Dear Readers,

As you may have seen elsewhere, in mid February my wife and I suffered the loss of our home in a fire, in the hills of central Massachusetts. The good news is that we got out safely and had no animals in our care at the time. The fire crews were able to contain the fire from spreading, in what turned into a 3-alarm, 5-hour-long ordeal in subzero temperatures; they did amazing work, and no one was injured. The bad news is that all of my physical historical materials and research of 30 years have gone up in smoke. As a result I have decided to suspend this blog for the time being. It will remain online as a resource for those interested in the history of glass and glassmaking in the seventeenth century and beyond. I do intend to resume writing when I can, but for now my time and energy are required in getting us back on our feet.

Friends are providing temporary shelter for us nearby and our intention is to rebuild as soon as possible. To those who have reached out with a steady hand, to those who have opened their wallets, and offered advice in our time of need, we thank you from the bottom of our hearts. In what are already difficult times for all of us, you have made a huge difference in our lives.

Paul Engle
6 March, 2021

Monday, June 29, 2015

Galleria dei Lavori

Giovanni Stradano  (Jan van der Straet) 
Alchemy Studio, 1571
(Inside the Uffizi Galleria dei Lavori)
In 1560, Cosimo I, Duke of Tuscany, commissioned Georgio Vassari to begin construction on the Uffizi Palace in Florence. Two wings of the structure frame a long, narrow courtyard leading out to banks of the Arno River. Today it houses one of Europe's premier art museums, but its original design was as the central administration of the Medici government. The lower floor held offices of the regional magistrates, and the upper floor of the west wing (above the mint) held a variety of workshops highlighting Tuscan industry. Grand Duke Cosimo de' Medici built a glass furnace there, which he staffed with Muranese masters of the art. He won their expertise through long, hard negotiations with the doge of Venice. 

A 1571 painting by Giovanni Stradano is entitled the Alchemy Studio. It shows Cosmo's son, Francesco I, in the Uffizi surrounded by laboratory equipment and workers. Under the watchful eyes of a senior alchemist, he stirs a chemical preparation over a stove with intense concentration. The prolific glassware in this scene drives home the close relationship between glassmaking and scientific investigation.

By 1588 Francesco's brother, Ferdinando I de' Medici, formally declared this space the Galleria dei Lavori or 'gallery of the works'. There is no direct evidence that Antonio Neri gained his education in alchemy at this facility, but it makes a very attractive candidate. Of note to this story is that a demonstration was performed for Ferdinando de' Medici that purported to turn half of an iron nail into gold; the work of German alchemist Leonhard Thurneysser. In the 1590s, when Neri was being schooled, several accounts describe that the nail (chiodo) remained on display for some time in the Galleria. Neri mentions the nail in his Discorso and Thurneysser is discussed in a 1601 letter to the priest from his friend Emanuel Ximenes.

This post first appeared on 16 August 2013.

Friday, June 26, 2015

Thévenot in India

Mirror ring with inlaid foiled glass
late 18th to early 19th c Rajasthan India.
This is the third and final installment of a series that has followed seventeenth century French tourist Jean de Thévenot from Europe to the Levant and then into Syria. We have specifically looked into his diary with an eye toward passages that mention glass or glassmaking. While our intrepid traveler had no special connection to this art, he did possess a keen, inquisitive mind; collectively, his observations about glass give us a glimpse into the state of affairs in the Middle and Far East in the mid 1600s.

We left off with Thévenot as he headed up the Tigris River toward Baghdad, in the autumn of 1663. While he was anxious to see Mughal India, actually getting there presented some difficulty due to hostilities between the Dutch, British and Portuguese, which extended to their trade operations around the world. After a first attempt was aborted, he made a strategic retreat to Isfahan and bided some time with shorter excursions from there. Finally, in the autumn of 1665 he booked passage on the originally English ship “Hopewell” recently purchased by an Armenian trader and captained by an Italian. [1] The ship departed from Basra and made port at Surat, India in January of 1666.

The city of Agra is in the Northwestern part of India, a thousand kilometers from Surat and the coast; it is known most famously as the home the Taj Mahal. When Thévenot passed through, he noted of the women “They wear a great many [rings], and as they love to see themselves, they have always one with a looking-glass set in it, instead of a stone, which is an inch in diameter.” [2]

These rings, set with a mirror, are known as “arsi” and can still be found in some areas around the country. Indeed, Sharma and Seth note in their 1997 book on contemporary regional costumes and ornaments that mirror rings were popular in the northern most reaches of India. In the western Himalayas at Chamba and as throughout India, they are still worn today. “Arsi or arsu means a mirror. An ornament with this name is a ring fitted with a round mirror or a looking-glass. It is usually worn on the thumb of the right hand. With the help of arsi, the hill woman can look at herself in the mirror and feel assured of her beauty in such places like fairs and festivals. Thus she can stealthily have a glance in the mirror whenever she desires, even in the company of males without feeling awkward.” [3]

Another reference states that in the seventeenth century arsi rings were worn by both men as well as women, but I have been unable to confirm this. In any event, they appear to have been wildly popular. On an earlier expedition through Aleppo, Syria, Thévenot observed “five or six hundred cases of [mirrored] glass” being shipped down the Euphrates River. When he expressed surprise at the rough handling, he was told “that it mattered not, though it were all broken into pieces, because the Indian men and women buy it only to have little pieces set in rings, which serve them for looking-glasses to see themselves in.” [4]

Thévenot’s first landing was in Surat on the west coast of India, about 300km north of Mumbai. In 1688, Captain Alexander Hamilton landed at the same port and recorded, “The [Muslim] women wear gold rings on their fingers, and sometimes one on their thumbs, with a small looking-glass set in it.” [5] Other travelers also noticed the rings:  In the 1660’s Frenchman Souchu de Rennefort observed similarly, “They wear also many [rings] on their fingers, and among the rest, one with a small looking-glass in it, which serves them to contemplate themselves.” [6]

The earliest account I have been able to find recounts not a glass mirror but one of metal. On 25 September 1637, ambassadors from the Danish duke of Holstein were visiting the King of Persia and were entertained by six dancing women from India. The women were accompanied by their husbands who played musical instruments. “Some of them had bracelets of pearl, others of silver, but they had all rings on their fingers, and among the rest, they had upon the thumb, upon which in the place where the stone should be, there was a piece of steel, about the bigness of a crown-piece of silver, and so well polished that it served them for a looking-glass.” [7]

As these accounts suggest, vanity may well have been the motivation for the popularity of the arsi rings, but it is worth noting that mirrors did play a role in some religious practices. Wikipedia states, “The Nizhal Thangals and Pathis have, in their sanctuary, a mirror to reflect the images [of] worshippers. […] The mirror's placement symbolizes that God is inside oneself and it is of no use to seek God elsewhere.” [8] In some Muslim weddings of Southern India, a traditional ritual is called ‘Arsi-Mushaf’ or “the mirror ring and the Quran,” in which the newly betrothed observe each other through a mirror.

Thévenot stayed in India for over a year and crossed the country to its East Coast. Finally, he returned to Surat, sailed to Persia and traveled north back to Shiraz. He spent the summer of 1667 at Isfahan, after suffering an accidental gunshot wound. In the autumn, he started north for Tabriz, but died on the way at Meyaneh on 28 November 1667.


[1] Armenians in Asian Trade in the Early Modern Era, ed. Sushil; Kevonian Chaudhury (Keram). (France: Les Editions de la MSH, 2008) p. 106.
[2]Jean de Thévenot: The Travels Of Monsieur De Thévenot Into The Levant: In Three ..., Volume 3
 (London: Archibald Lovell Faithorne, 1687)v. 3,  p. 38.
[3] Kamal Prashad Sharma, Surinder Mohan Seth: Costumes and Ornaments of Chamba (New Delhi: Indus Publishing,1997), p.113
[4] Jean de Thévenot: “The Travels of Monsieur Thévenot Into The Levant” (London: H. Clark, 1687), v.2, p.40.
[5] Alexander Hamilton, A New Account of the East Indies: Giving an Exact and Copious ..., Volume 1(London: C. Hitch; and A. Millar, 1744) v. 1, p. 165
[6] Gabriel Dellon, Jodocus Crull, Souchu de Rennefort: A voyage to the East-Indies: giving an account of the isles of Madagascar (London: D. Browne, 1698) p. 25
[7] Adam Olearius, John Davies, Johann Albrecht von Mandelslo: The Voyages & Travels of the Ambassadors from the Duke of Holstein, to the ... (London: Thomas Dring, and John Starkey, 1662), p.277
[8] Wikipedia: https://en.wikipedia.org/wiki/Ayyavazhi_rituals

Wednesday, June 24, 2015

Alchemist Priest

"Brother Mauritio" detail from
Tesoro del Mondo  (Treasure of the World,) 
by Antonio Neri 1598-1600, f. 19r.
The fact that Antonio Neri was both a dedicated alchemist and a Catholic priest may seem a bit odd to current sensibilities. If we take a broader view and try to accommodate history, the situation can seem odder still since in Neri's time, the late sixteenth to early seventeenth century, alchemists were sometimes portrayed as practicing sorcery. As far as the Church was concerned, sorcery was a heretical offence. In some quarters, the seemingly miraculous manipulations of alchemists to duplicate or even improve on materials found in the natural world were seen as tapping into divine powers. As the bubonic plague ravaged Europe, finger pointing at suspected culprits for bringing down the wrath of God was not terribly uncommon. Nevertheless, the fact is that Antonio Neri was both a Catholic priest and an alchemist, and in good standing on both counts. To understand how this could occur, we need to scratch beneath the surface of history a little deeper.

Taking an even longer view, we see that both religion and alchemy have been practiced for a very long time, since before recorded history. Both conferred cohesive benefits to society and both required the keeping and passing of secretive knowledge. In this light it becomes very reasonable that the two disciplines might be conducted by some of the same people. Muslims, Hindus, Buddhists, Jews, Christians, all have rich traditions of alchemy that stretch back to their beginnings. That religion and alchemy coexisted for so long is really a pragmatic issue; alchemy formed the foundation of medicine, metallurgy, the production of paints and many other arts. It was essential to even very small communities, not to mention the advent of distillation: the art of producing a good stiff drink. When a religion, any religion, was adopted into a community, the practices of the community were also adopted into the religion. From this we can infer that the ancient practices that eventually became alchemy were alive and well in the prehistoric Mediterranean tribes, in Celtic and Etruscan societies and in the Asian states long before written history. 

Now, returning to the early 1600s and Antonio Neri, many Christian orders boasted long traditions of alchemy. The Dominicans had Albertus Magnus, the Franciscans had Roger Bacon and Ramon Llull. It is true that in the fourteenth century, Pope John XXII signed a decree banning the counterfeiting of gold and silver by alchemical means, but this has often been wrongly interpreted as a general prohibition, which it was not. In fact, there is every indication that this pope, a trained physician, was well acquainted with the positive benefits of alchemy. Furthermore, the prohibition did not it stop a long line of chemical experimenters within the Church from trying their hand at gold transmutation. In a more pedestrian vein, monks in far-flung monasteries regularly maintained herbal gardens from which they distilled medicines and spirits, and made pigments for paints using alchemical methods. Monasteries were the repositories of knowledge and within their walls, alchemical texts were studied closely.

Neri's specific affiliation, his sect, within the Church is currently unknown although there are a few good guesses. His sponsor was Medici prince Don Antonio, who maintained a palace laboratory called the Casino di San Marco on the north side of Florence; this is where Neri worked at the beginning of his career. The laboratory was located directly across the street from one of two apothecaries maintained by the Dominicans. It is hard to imagine that there was not some kind of relationship between two facilities, both practicing alchemy mere steps from each other on opposite sides of the same street. This apothecary was part of the San Marco Convent complex, which a century earlier harbored Savonarola. There are strong indications that Neri’s family was sympathetic to his reform minded agenda. Savonarola sponsored the first Florentine pharmacopoeia -- a book of medicinal recipes used by physicians and apothecaries. Neri's father, who happened to be the grand duke's personal physician, presided over a later revision of the same book.

Neri's sponsor, Don Antonio, held high office in the Knights of Malta, a religious military order which reported directly to the pope and had great latitude in the types of projects it pursued. The Knights of Malta ran two churches in Florence and Neri can be connected to both.  The order traces its roots to the crusades and has various associations with alchemy such as George Ripley. One legend tells that Ripley helped to finance the knights through the production of alchemical gold. The knights followed the rule of Augustine and enjoyed a close relationship with the Augustinians.

The Augustinians counted a Francesco Neri as abbot of their San Clemente monastery near the Casino. The same abbot Francesco also worked for Don Antonio de' Medici at the Casino and may have been Antonio's brother. Antonio's aunt, Faustina, apparently entered an Augustinian convent after the death of her husband. 

But there is no shortage of other possibilities; as a child, the priest's home parish church was the Benedictine San Pier Maggiore. His father was buried at a Cistercian church, his grandfather at the Franciscan cathedral. At the end of his life, Antonio Neri's confessor was a Carmelite, but also served as the parish priest of an abbey run by the Canons Regular of the Lateran. Whichever group served as his base of operations, through Antonio Neri, they continued a very long tradition of alchemy practiced within the Church.

Monday, June 22, 2015

Waxing Moon

In Chapter 5 of L'Arte Vetraria, Antonio Neri shows how to extract salt for glass from fern plants in an evocative recipe. Fern was and still is widely abundant in Tuscany. It presented a ready source material for glassmakers of the region. Neri directs that harvesting of the plants be done in the spring:
Cut this herb from the ground when it is green, between the end of the month of May and mid June. The moon should be waxing and close to its opposition with the sun, because at this point the plant is in its perfection and gives a lot of salt, more than it would at other times and of better nature, strength and whiteness.
At first, it is tempting to dismiss this lunar influence as the product of a fertile imagination, but let us take a closer look. Tidal forces of the moon do in fact subtly affect plants, fish and animals in ways that can be measured. A closer look at Neri’s advice reveals reasoning that is hard to dismiss as mere astrological superstition. When the moon is waxing, tides rise and so do water tables. According to folklore, this is when sap rises from the roots of plants into stems and leaves. Sap carries the dissolved mineral salts required for glass. Neri also stipulates that harvesting should take place during lunar opposition. When the moon is 'opposed' to the sun, it is on the opposite side of the earth from the sun. In opposition, the moon is near full and rises as the sun sets. Plants see more light at night, leading to increased photosynthesis and growth.

In contrast, violin makers from Cremona valued high alpine spruce called moon wood. Trees were felled in the wintertime, when lunar tides were low. This minimized the amount of vibration deadening sap in the wood. In his Natural History, Pliny relates Cato’s advice on felling trees in accordance with the lunar cycle. In fact, centuries-old tradition specified lunar conditions for a host of needs from construction timbers to cheese boxes.

This post first appeared on 5 August 2013.

Friday, June 19, 2015

Weights and Measures

Ford Madox Brown,  The Manchester Murals: 
"The Proclamation Regarding Weights and Measures, 1556."
In his book L'Arte Vetraria, Antonio Neri's glass recipes depended on precise amounts specified in units as small as the 'grano,' [grain] named after the weight (mass) of a single grain of wheat or barley. In interpreting his formulas, the glassmaker must understand the quantities he used. For us, there are unfamiliar units like the 'fiasco' and the 'dita.' The dita or digit was simply the width of a finger. A fiasco or flask was the volume of a glass wine bottle, about two-and-a-quarter liters in Florence or two-thirds of a US gallon - about half of British imperial gallon. (As an aside, there are many fanciful stories of how the word 'fiasco' came to be synonymous with failure or disaster, perhaps the most believable is that the losers of competitions or bets were expected to buy the next round of drinks.)

In addition to unfamiliar units, there is the problem of standardization; a pound in Florence weighed different from a pound in other areas as close as Massa or Piedmont. Each Italian city maintained its own set of master weights and volumes to which merchants were expected to adhere. In reality, the differences were minor and may have been more attributable to politics than accuracy. Since antiquity, commodity merchants realized that if their own set of weights used in sales were ever so slightly below the norm, over time a savings would be realized, not large but significant. Towns could apply this principle as well; it paid to set standards slightly above or below neighboring towns from which one was buying or selling various goods. In truth, the differences were not great simply because successful commerce demanded that buyers and sellers could agree and strike a deal.

Even in different countries throughout Europe and the Mediterranean, we find close agreement in the various units of measure. Neri's first translator, Christopher Merrett, made an interesting substitution in his 1662 English version of L'Arte Vetraria. In chapter 132, Merrett writes "six pints of water" for Neri's "libre sei di acqua," changing pounds into pints. At first, it seems odd to be converting weight into volume, but this was perfectly valid. At that time in England, the pint was defined as exactly a pound (of wine or beer). Sailors were often each allotted a pint a day; the pint was also one-eighth of a cubic foot. (A cubic foot was equivalent to a gallon.) This system was very convenient for shipping companies who needed to calculate cargo volume and ballast in their trade ships as well as avoid mutiny by running out of beer at sea. Later, in 1824 King George IV increased the gallon from eight to ten pounds of water, invalidating Merrett's substitution.

Other conversions were more problematic. As absolute measurements varied from place to place, the size of a batch would be larger or smaller; not a big worry. However, ratios were of critical importance to a recipe. Just as in baking a cake, an entire batch of glass could be ruined by changing the ratio of materials. This sort of difficulty was especially prevalent with the size of an ounce; the troy and apothecaries system were based on a twelve-ounce pound while the avoirdupois system used a sixteen-ounce pound. When Merrett wrote his translation, England had officially been under the avoirdupois system since Henry VIII (although, In 1588, Elizabeth I complicated matters further by raising the weight of a pound by about twenty-one percent.) Meanwhile, Florence and much of Europe continued to use the troy system.

English glassmakers who wished to use Neri's book as a working document would need to know which system to use. Merrett's direct translation added a hurdle that would confuse the unaware. In order to approximate Neri's intended composition under the prevailing avoirdupois system, Merrett's "ingenious" (as he called them) British readers would need to decrease by 1/5 quantities specified in pounds, and increase ounces by 1/15.

This post first appeared on 18 September 2013.

Wednesday, June 17, 2015

Old Post Road

In the winter of 1603-1604, Antonio Neri left Italy to visit his friend Emmanuel Ximenes in Antwerp. There is no way to know the exact path he took, but based on the advice in Ximenes' letters and on well-established trade routes; a good estimation can be made. It is likely that Neri was starting from Pisa. The path  suggested by his friend took the priest first back east to Florence, then perhaps through Bologna, Ferrara and Padua to Venice. Ximenes offered to make arrangements for Neri to travel from Venice with traders headed to the Frankfurt fair held at mid-lent. There would have been plenty of time for him to celebrate Advent in Florence and Christmas in Venice before his caravan headed north. The group could have left as late as the end of January.

Ximenes suggested that Neri travel with the courier from Florence to Venice. He was referring to the system of coaches that delivered the mail throughout Habsburg Europe, run since the early 1500s by the De Taxis family. While the Medici and other heads of state maintained their own fast couriers for diplomatic and military messaging, the De Taxis had a monopoly on almost every other piece of correspondence, a privilege for the family that was later extended to other parts of the world by the Holy Roman Emperor. They ran an efficient system well into the eighteenth century. An elaborate series of 'posts' were set up at intervals, where tired horses were watered and swapped for fresh steeds and riders so that the journey could continue uninterrupted. Independent travelers could partake in the system for a fee based on equipment required and the weight of luggage. In Neri's time, accounts were settled at each post and travelers could elect to stay over in a town and pick up a later expedition. On well-established popular routes like between Florence and Rome, travelers could pay a flat rate that included lodging and meals. If Neri had traveled light and spoke some German, he might have completed the entire journey in as little as ten days; the time letters from Venice to Flanders took to arrive. However Ximenes advice suggests a longer excursion.

I would recommend that you should go with the courier from Florence to Venice, arriving in Venice in time that you would be able to accompany the merchants who come to the fair held in Frankfurt at mid Lent;  you  will stay there the length of the fair for fifteen days, which will not displease you for having seen it. After that, you would go in the company of other merchants to Cologne, and then with them or others, by land or sea to Holland, ending up at this city. This sea, however, is nothing more than rivers. I recently went by land to Basel and from there by water ending here. But for Your Lordship,  who does not speak the German and Flemish languages, I would consider better the way that I say, with merchants from Venice to Frankfurt and then with others by water to arrive here. 

On Embarking from Venice, the party of traders would head west, back to Padua, on to Verona and then north along the ancient trade route through Bolzano to the Brenner Pass. The journey from Venice to Frankfurt was about 600 miles (950 km). Traveling an average of 30 miles per day, they would be on the road for three weeks. Depending on their itinerary, the journey could have varied by a week in either direction. The start of the fair was mid-lent, the date of the traditional feast held three weeks before Easter. In 1604 mid-lent Sunday fell on 28 March.

Brenner is the lowest pass across the central Alps, connecting Bolzano on one side to Innsbruck on the other and was passable year round. The distance of this, most difficult part of the journey, was about 75 miles (120 km), with a vertical climb of 4,495 ft (1,370 m), almost a full mile, but all below the tree line. Assuming a slow pace for pack animals, this segment could still be completed in less than a week, stopping in Bressanone, (Brixen), then at the alpine city of Vipiteno (Sterzing), where perhaps some extra time was taken to rest and view the nearby silver mines. Gries am Brenner was just over the pass on the Austrian side. With the majestic Wipp valley (Wipptal) at their backs, the remaining journey was down hill from there. From Innsbruck, the traders would head towards Augsburg, perhaps with an excursion through Munich, which was then the capital of Bavaria. The route from Augsburg through Wurzburg to Frankfurt was riddled with small towns accustomed to hosting traders since Roman times. After a few weeks on the road, the fair at Frankfurt would have come as a welcome diversion.

At the end of the fair, a week before Easter, Neri would start the final 250 miles (400 km) of his journey. First, he would travel over land with merchants or the Ximenes family servant to the walled city of Cologne on the Rhine River. Next, he would move by water toward the sea. The northern route, along the Rhine, avoided the military conflicts between the Dutch Republic and the Hapsburg Empire. The most dangerous were between Liege and Antwerp. From Rotterdam, the inland waterways led south to Antwerp. Priest Neri may well have arrived in time for Easter Vigil.

This post first appeared in a shorter form on 21 October 2013.

Monday, June 15, 2015

Thévenot Continues East

Stained glass windows of the Nasir al-Mulk 'Pink Mosque', Shiraz, Iran
Photo by Domiri Mohammad Reza Ganji.
Previously, we followed the progress of seventeenth century tourist Jean de Thévenot, noting his comments about glass as he traveled. He sailed from Rome to Malta to Constantinople to Egypt. He then continued overland through Syria and sailed down the Euphrates River toward the Persian Gulf.  At Basra he turned around and headed north, picking up the Tigris River to Baghdad where he continued eastward to Persia. In Isfahan he described numerous species of plants, animals and insects. Further south he took note of a city where glassmaking captured his attention:


The people of Schiras [Shiraz, Iran] are very witty and the city hath given birth to most of the best poets of Persia. There is much glass made there, and several glass-shops are in town, though they work not constantly in their glass-houses, but let the fire go out after they have employed a certain quantity of materials. They make their glass of a white stone, almost as hard as marble, which they get in a hill four days journey from Schiraz and it is very clear: especially they make great bottles as clear and delicate as in any other place in the world; but it is wonderfully strange how they can blow the great bottles they call ‘Caraba,’ which are as thick as one finger and hold nearly thirty quarts of wine; these bottles are covered with the straw of canes. [1]

Preceding Thévenot in Shiraz by a number of years (1627) was the British traveler, Sir Thomas Herbert, who stated that there was “…no part of the Orient showing better or richer wine.” [2] The mutually beneficial association between the production of wine and glass is one that appears in numerous locations throughout history. That both crafts should occur here, at the center of activity for this region’s premier vineyards should be no surprise. 

The region’s ‘Shirazi’ wines have been connected by various legends to the French Rhone variety now known as ‘Shiraz,’ but the vineyards in Iran are now defunct, and no definite conclusions have been reached, except that if a kinship exists, it is a very ancient one. In other quarters, Marco Polo mentioned Persian wines [3] and Omar Khayyam praised them throughout his Rubaiyat. [4]

At the same time that Thévenot passed through the region, so did fellow Parisian Jean Chardin (Sir John Chardin) who spent about eighteen months visiting (1666-7). It is unknown if the two travelers met. In his own published diary Chardin stated  “The art of glass-making; there are glass houses all over Persia, but most of the glass is full of flaws […] The glass of Chiras [Shiraz] is the finest in the country” and he went on to say that “Moreover, the art of glass-making was brought into Persia within these four score [80] years. A beggarly and covetous Italian taught it at Chiras for the sum of fifty crowns.” [5]

This last passage is often quoted in reference books without comment, to the point that it has become quite famous. At the risk of stating the obvious, the notion that one man, a foreigner, down on his luck, could single handedly bootstrap an entire industry that would fully mature throughout Persia in eighty years is absurd on its face. Beyond that, it is something of an insult to a culture that current scholarship credits with key developments in the invention of glass more than five thousand years ago. [6] Chardin’s condescendence toward Persian artisans and craft in general is well demonstrated throughout his book. His claim is plain enough, however if we want to be charitable, we could speculate that he misunderstood his source, who actually told him that the Italian was responsible for showing European style glassmaking to a well established technical community in Shiraz. Historian Stefano Carboni identifies a fifteenth century downturn and says “in Iran the industry was revived with the help of European, mostly Venetian, craftsmen in Isfahan and Shiraz from the seventeenth century.” [7]

[1] Thévenot v.2, p. 125, 126
[2] Thomas Herbert  “A Relation of Some Yeares Travaile, Begunne Anno 1626.” (London: Stansby and Bloome, 1634), p. 133.
 By Thomas Herbert   also see http://www.saddleflasks.com  “An extensive reference site devoted to Late Persian glass.”
[3] By Marco Polo, “The travels of Marco Polo, the Venetian,” trans. by William Marsden (London: J.M. Dent, 1926), p. 41 (bk.1 ch. 15).
[4] Omar Khayyam, “Rubaiyat of Omar Khayyam” trans. by Edward Fitzgerald (Boston: Branden Books, 1989), for example, stanzas VI, XI, XII, XLI, LVI.
[5] John Chardin “Sir John Chardin's Travels in Persia” (New York: Cosimo, 2010) p.275  (abridged English translation of 1724 original).
[6] For instance, see  https://en.wikipedia.org/wiki/History_of_glass http://www.iranicaonline.org/articles/glass ,  https://en.wikipedia.org/wiki/Sasanian_glass .
[7]  Stefano Carboni, “Glassware” in Medieval Islamic Civilization: An Encyclopedia edited by Josef W. Meri (New York, Routledge, 2005) v. 1, p. 298.

Friday, June 12, 2015

Travels To The East

Jean de Thévenot, from
"Relation d'un voyage fait au Levant" (1664)
In 1652, at the age of eighteen, a wealthy Frenchman named Jean de Thévenot finished his studies at the University of Paris. He celebrated his achievement with a grand tour that would take him, not just through Europe, but unexpectedly half-way around the world. In Rome, he befriended fellow Parisian, Barthélemy d'Herbelot, where they conspired to travel together to the Levant. 

Circumstances detained d'Herbelot and after waiting five months in Malta, Thévenot gave-up on his companion and set out on his own to Constantinople. Four years later, in 1659. He returned home only to prepare for an even more epic adventure, one that would last until his 1667 death in Azerbaijan from an accidental pistol shot. 

Thévenot kept a travel diary, he picked up languages easily and endeavored to blend-in to local culture as much as possible. Throughout his travels he made keen observations of people, customs and of the natural world around him. He published a volume of his adventures to great acclaim, two more would follow after his death. In 1687 his work was translated into English, when it found a whole new audience. 

Of special interest to us are his numerous observations about the glass trade. This was a subject to which he had no special interest or connection, but his natural curiosity and communication skills open a window into an otherwise poorly documented piece of the glass history puzzle.

On Malta, even before embarking for the Far East, he notes that “sore eyes” are a problem because of the bright sun on the white (limestone) earth of the island “which makes many commanders and knights wear green spectacles”; certainly an early incarnation of sunglasses. [1] In Constantinople (today Istanbul) he visited the great mosque Hagia Sophia and remarked “it is full of lamps and curiosities in glass balls, of which one for instance, contains  a little galley, well rigged, another a model of the mosque in wood and the rest a great many pretty knacks of that nature.” [2] Having booked passage out of Alexandria, Egypt on an English gun boat, he explains that the sailors kept track of their speed with a “little slat and very thin piece of wood tied to a line and when they throw it into the sea, they turn a half-minute sand glass […] every seven fathoms of the line making a mile in an hour.” [3] This is the origin of the nautical unit of speed known as the 'knot', the method of paying out line spaced with knots tied in the line at intervals of  8 fathoms - 47 feet 3 inches (14.4 m). This method of reckoning progress with a line was used well into the nineteenth century, the units are still used today, both for boats and aircraft.  A vessel travelling at 1 knot along a meridian travels approximately one minute of geographic latitude in one hour. [4]

In Damascus, Syria, he visited the great mosque there (Umayyda). Some natives kindly offered to take him in, disguised with a turban on his head, but he declines, fearing that if discovered, he will be forced to choose between his life and his Christian faith. Nevertheless he walks around the tremendous structure and observes that “The pavement is all of lovely stones that shine like lookinglass” and he continues “I went up to the terrace-walks, to the windows of that mosque, which are made like the windows of our churches and have panes of glass set in plaster, which are wrought into figures.” [5]

West of Aleppo, Syria, on the banks of the Euphrates River, Thévenot explains that, “barks loaded with glass (of which I will presently speak,) go to Bassora [Basra].” A ‘bark’ or ‘barque’ was a small three masted sailing ship. “While I was at Aleppo, the Sheik Bandar hired a bark to carry five or six hundred cases of glass, which he sent to the Indies.” And “I wondered to see that they who baled up these chests for the Sheik Bandar, tumbled them so rudely that they broke all the glass; but they told me, that it mattered not, though it were all broken into pieces, because the Indian men and women buy it only to have little pieces set in rings, which serve them for lookinglasses to see themselves in. That glass is all over laid with quicksilver on one side and is a very salable commodity in the Indies and profitable to the merchants.” [6]

One implication from this passage is that the named Sheik Bandar ran a glassmaking operation in Aleppo. It is interesting to note that Florentine glassmaker Antonio Neri had an uncle, his father’s brother Francesco, who was a merchant living in the Tuscan enclave inside Aleppo about sixty years earlier.

In the next installment we will continue to follow the thread of glassmaking references in the chronicles of Thévenot’s travels which take him to Persia, where he finds a glassmaking center.

[1] Jean de Thévenot, “The Travels of Monsieur Thevenot Into The Levant” (London: H. Clark, 1687) v.1, p. 6.
[2] Ibid, p. 22.
[3] Ibid, p. 268.
[4] See Wikipedia http://en.wikipedia.org/wiki/Knot_(unit).
[5] Ibid, v.2, p 17.
[6] Ibid, p.40.

Wednesday, June 10, 2015

Neri in Pisa

Majolica vase by Niccolò Sisti,
decorated in the grotesque style.
Antonio Neri's career in glassmaking took him from the city of his birth, Florence, to Pisa, Antwerp and possibly other places yet to be confirmed, like Rome and Venice. Under the reign of Grand Duke Ferdinando de' Medici, a glass furnace at Pisa became an important source of diplomatic gifts in both glass and ceramics. Antonio Neri worked at this facility in the first years of the seventeenth century. Later, the same foundry would receive an order for exceptionally clear glass to be used by Galileo in his telescopes. It is unknown how that project worked out, but the furnace master Niccolò Sisti made a name for himself supplying glassware to the Vatican, the king of Spain, and many nobles throughout Italy and Europe. Undoubtedly, Neri's glass career was strongly influenced by his tenure in Pisa with Sisti. 

In the early seventeenth century, there were several glass furnaces in Pisa. One was run at the pleasure of Grand Duke Ferdinando by Niccolò Sisti. Raised in Norcia in Perugia, he likely learned his trade at an early age;  Sisti's father, Sisto de' Bonsisti, was said to be an expert in making paste gems. This would account for the son's apparent skill in the medium of glass in addition to his ceramics prowess for which he was previously employed at the Casino di San Marco in Florence. For Neri, working at Sisti's glass house in Pisa played an important role in his glassmaking education. Sisti would serve three Medici grand dukes, Francesco I, Ferdinando I and Cosimo II. When work came to a stop at the Casino di San Marco, after Francesco’s death, Sisti may have opened his own factory in Florence for a short time, but then moved to a new facility in Pisa.

 In 1592, Grand Duke Ferdinando set up a glass shop in the central part of Pisa, along the north bank of the Arno River. This furnace was staffed by Muranese workers and was located in the city center, along the river. Archaeologists have unearthed its remains in the courtyard of what is now 43-44 Lungarno. The operation was capitalized with a loan of five hundred scudi made by Ferdinando I to Sisti, with a special mandate: he was to introduce new forms of pottery to the region. In addition to glass, the furnace at Pisa would produce soft-paste porcelain and majolica ceramics. These were both forms that Sisti had helped to develop when he worked in Florence at the Casino; he was involved in Francesco’s quest to duplicate Chinese porcelain.

In 1602, Neri was to be found working alongside Sisti at the Pisan furnace. According to his own account, this is where he worked on special colors, and collected river stones for glass frit. Here he made kermes based paints, enamels and used ferns as an alternative plant salt for glass. In all likelihood, he would have had access to the nearby botanical gardens and the small adjacent laboratory located just a few blocks from the glass furnace. 

Early in 1604, the priest would make his trip north to Antwerp to visit his friend Emmanuel Ximenes. During Neri's seven year absence, Sisti's projects included cristallo table service for the Vatican, and special glass for the lenses of Galileo's telescopes. Upon Neri's return from Flanders, we again find him working in Pisa, this time on alchemy. In a copy of his last known manuscript, a heading reads, "Techniques copied from an old book here in Pisa."  The university at Pisa was an intellectual center and a repository of technical knowledge. There, Neri had access to a wide range of materials in the libraries. The furnaces and laboratories provided him with hands-on experience, but there can be little doubt that he was a voracious reader as well. On the same page of this manuscript appears the date 26 January 1614. This is the last known specific information on the priest's whereabouts, since he would be dead within the year, at the age of thirty-eight.

*This post first appeared here in a shorter form on 18 October 2013.

Monday, June 8, 2015

We were Trojans

Giovanni Domenico Tipeolo, 
Procession of the Trojan Horse in Troy. 1773
In January of 1600, Antonio Neri finished an ambitious manuscript called Treasure of the World, which was devoted to "all of alchemy." On the first page of text after the contents, above the first recipe, on the first line, written in Neri's own hand, are two solitary words, "fuimus troes"; a celebrated quote in Latin from Virgil’s epic poem, The Aeneid. The words translate to "We were Trojans" or more specifically "We Trojans are no more." They lament the fall of a city, sparked by the deception of the great wooden horse concealing enemy soldiers. These were words spoken in grief, in a charged, emotional scene, accepting defeat. We were once proud Trojans, but no more. While the intended significance in Neri’s manuscript may be lost, it is further affirmation of his academic grounding. What rings through the fog of history in these words, is the unmistakable passion behind them.

        Tis come, the inevitable hour,
        The supreme day of Darden power;
        Our history’s ended: Troy’s no more,
        And all her mighty glory o’er. 
            - Aneid 2,324.
            (William King, trans.)

The scene in the Aeneid takes place at night, under the stars. The hero Aeneas  sound asleep, wakes from his bed to the burning pillage of his city. After years under siege, the gates of Troy were breached – not by brute force, but by cunning deception. The streets are in flames, piled with the bodies of slaughtered innocents. Panthus, the priest from the temple of Apollo, with his grandson in tow, runs to Aeneus and exclaims that Troy and the Trojans are no more: "Fuimus Troes, fuit Ilium." He entrusts Aeneus with the sacred vessels and icons from the temple. Aeneus fights his way out to safety, carrying his own father on his back. He goes on to wander the Mediterranean. Later he enlists the help of the Etruscans (the ancient Florentines). Together, on the banks of the Tiber River, he fulfills his destiny by founding the city of Rome, or so the story tells.

In its broadest interpretation, those two words written by Virgil in the first century BCE, fuimus troes, have since been used to evoke the human drive to continue after a devastating blow. The loss of their widowed father in 1598 put the Neri children into a similar situation. The following year, Antonio's younger brother Emilio died at the age of sixteen on Christmas day. Two simple words scribbled at the top of a manuscript, yet they evoke the imagery of a man fighting his way out of a burning city, carrying the temple's sacred treasure. Behind all the recipes for glass and medicine and alchemy, there is a man of flesh and blood, one who felt life’s cruelties yet did persevere.

This post first appeared on 30 August 2013.

Friday, June 5, 2015

Artificial Gems

Pastes (glass) set in silver openwork (Portugal c. 1750)
Victoria and Albert Museum, London.
Acq. nr. M.68-1962
In many ways, the story of artificial gems traces the story of glass technology itself. From ancient times, when glass could only be produced in very small quantities it was regarded and used as a type of stone that was made through art. Alchemists thought the bright colors produced by metallic pigments in glass were a key to the philosopher's stone, and the transmutation of base metals into gold. As the technical prowess of glassmakers expanded, so did the ability to simulate specific stones, most notably coveted gems. Glass went on to be used as material for utilitarian objects like goblets and as an indispensable part of scientific enquiry. All the while, artificial gems have continued to dazzle us with their beauty. 

In the fifth part of Antonio Neri's 1612 book, he teaches the secrets of making artificial gems "of so much grace, and beauty, that they will surpass the natural stones in everything except hardness." It is not a difficult argument to make that this section alone is responsible for much of the lasting popularity of L'Arte Vetraria. It is easy to see why enterprising artisans would want to make glass imitations that could pass for the real thing. It is also perhaps too tempting to jump to the conclusion that Neri intended his recipes to be used in deception, since there is no evidence whatsoever that this was the case.

Neri gives full credit for his innovative methods in paste gems to Dutch alchemist Isaac Hollandus. Hollandus is an enigmatic figure, whose writings survive, but not much is known of the man, his family, or even if he was living in Neri's time. What is known is that Antonio's dear friend Emmanuel Ximenes was the brother-in-law to Baron Simon Rodriguez d'Evora, a famous diamond dealer and jeweler of choice to royalty throughout Europe. He lived and worked on the same street in Antwerp as Ximenes' palace, only a few steps away from Neri's new temporary home. It was a common request of wealthy patrons to have duplicate jewelry made in paste for travel and security reasons. If a fake necklace or jewel could pass for the real thing, it was well worth the added expense, when the genuine article could remain safe under lock and key.

No artificial gem recipes have ever been found among Hollandus' writings, excepting one for ruby which is then crushed up as part of a prescription for the philosopher's stone. It is quite possible that Neri was applying a more general technique from the Dutchman. The basic material for all of Neri's paste gems is a fine lead crystal. The crux of his innovation lay in the form of lead used. Normally, metallic lead sheet was cut into small pieces, and roasted in a kiln such that it would oxidize into powder, but not melt. The powder was then added to the glass melt. In Neri's method the lead was chemically converted into a water-soluble form, which could then be filtered and purified to a much greater extent. The end result was a far better grade of crystal.


In 1697, Jean Haudicquer de Blancourt translated into French and greatly expanded Christopher Merrett's English edition of Neri. Blancourt gave no credit to the Italian for his work, and two years later, when it was translated back into English by Daniel Brown, the connection to Neri was completely lost, but the credit for paste gems remained with Hollandus. In the eighteenth and nineteenth centuries, numerous general encyclopedias of art and craft were published and the so-called 'Hollandus' paste gem recipes turned up many times. Meanwhile, a properly credited French version of L'Arte Vetraria was completed by Holbach in 1752. This edition was more suited to a scientific audience; he faithfully translated the Italian, but also incorporated the full comments of Merrett as well as those of Kunckel who issued his famous German version of Neri in 1679.

For more reading on Neri's artificial gems see Glass as Pasta and on the work of later investigators see Marieke Hendriksen at The Medicine Chest
*A shorter version of this post appeared here on 16 September 2003.

Wednesday, June 3, 2015

Dear Friends

The library of the University of Leiden (1610)
Christophe Plantin worked here from 1583 to 1585.
One day in July of 1601, in Florence, early in the morning, we imagine two men shaking hands, embracing and saying goodbye. Both knew it might well be the last time they saw each other. The older man climbs into a coach bound for his home in distant Antwerp and signals the driver to begin his journey. That man, Emmanuel Ximenes, had been in Florence to visit his sister, Beatrice, his brother, Niccolò, and several other relatives living in the area. Antonio Neri first met the wealthy banker at the home of Beatrice and her husband, Alamanno Bartolini. The priest lived there after his ordination and, according to nineteenth century historian Francesco Inghirami, functioned as house-master. Both men wished for more time together; they shared a fascination with alchemy and with the work of Swiss-born physician Paracelsus. They had become fast friends and formed a bond that would last until the end of their lives.

As soon as Ximenes arrived home in Flanders he wrote to Neri, on 17 August, 1601, "to the quite magnificent clergyman Mr.Antonio Neri, in the house of Mr. Alamanno Bartolini, in Florence, or where found." He expressed his great pleasure at receiving a booklet of recipes from Neri and declares him "molto caro" [most dear]. He goes on to warn his friend: "With your permission, I will not fail to bother you with my tiresome letters." Over the next two years, the men corresponded frequently. A set of twenty-seven letters written by Ximenes and one by his brother Eduardo, addressed to Neri, survive in the National Library of Florence. The two men discuss a wide variety of subjects including herbal remedies, glassmaking, enameling and in more careful language, the topic for which they were both most passionate: alchemy. They trade information on the results of their experiments and by 5 December, 1602, the banker wrote:

I have seen the tender affection which Your Lordship shows me and demonstrates with the hope to see me before death, which is no different from my own hope. I have desired this from the start… because if we were together, we could easily set to work on some small projects, being that our talents, if I am not deceiving myself, are very well suited...
Neri would ultimately make the journey to Antwerp, but not for another year. That winter he became quite ill in Pisa, postponing his planned visit. Finally, on 2 May, his friend wrote: "Praise God that your indisposition has ended." By the following spring the two men were reunited and Neri would spend the next seven years in a city that was in the eye of a storm. The low-countries (what today is the Netherlands and Belgium) were in the midst of a bloody civil war. The port of Antwerp was blockaded by the Dutch fleet and the countryside was being ravaged by troops from Spain and the Holy Roman Empire. The population of Antwerp was a shadow of its former self, but the city was left untouched by both sides, in an accord of political convenience. It had been burned and pillaged as recently as the 1570's, but by the early 1600's Antwerp was simply too valuable a jewel to be sacrificed.

Emmanuel's immediate family was among the wealthiest in Antwerp and strong patrons of the arts. He counted among his close friends humanist printers Christophe Plantin and Jan Moretus. Other branches of the Ximenes family topped the social ranks in Venice, Hamburg, Lisbon and Florence. Their ancient ancestors were kings of Pamplona, Navarre, Castile and Aragon. Emmanuel's father Rodrigo headed the prestigious Ximenes (Jiménez) Bank in Antwerp. By the end of his visit, Neri would present the prince of Orange with vessels of his chalcedony glass.


This post was first published here, on 6 September 2013.

Monday, June 1, 2015

Agnolo della Casa

Spine of volume 3 of Della Casa's notebooks,
Biblioteca Nationale Centrale Firenze.
At the turn of the seventeenth century, when Priest Antonio Neri was employed in Florence by the Medici prince Don Antonio, he worked closely with another alchemist by the name of Agnolo della Casa. Casa chronicled Neri's work and after his colleague's death in 1614, he undertook a special mission for Don Antonio to interview Neri's other associates and uncover the priest's recipe for the philosopher's stone. Don Antonio went as far as consulting a medium in Venice to contact Neri in the afterlife, but that is a story for another time. 

Thousands of pages of notes relating to Antonio Neri's work in Florence were recorded by fellow alchemist Agnolo della Casa. A significant portion of this nineteen-volume transcript is devoted to Neri's work on transmutation and specifically on the fabled philosopher's stone. The trouble is that he wrote much of it in obscure language, which renders it among the most cryptic in the entire canon of alchemy. Other sections of Della Casa's notebooks contain copies of the works of various adepts including Geber, Ramon Llull and Arnold Villanova. Neri took a keen interest in all of them.

In 1597, Prince Don Antonio de' Medici occupied the dormant Casino di San Marco and made it his new home. His father, the former grand duke, built this combination palace and laboratory on the north side of the city to indulge his own fascination with natural secrets. Don Antonio began to assemble a team that included Neri and Della Casa. The three men were all about the same age, in their early twenties, ready to do great things; ready to reveal nature and change the world.

In their time, it was reasonable to think that one metal could be 'purified' into another and that a single medicine could cure all disease or counteract any poison. These notions had been around since ancient times. In this realm, a skeptical eye was an absolute necessity, but there was no specific evidence that disproved the old stories. Don Antonio reportedly spent a fortune collecting recipes and testing them; he and his men worked to separate the real from the bogus. Swindlers and con men were in plentiful supply; they hawked miracle cures in public squares throughout Europe. Without a firm grasp of the underlying chemistry, the task of understanding a particular compound or chemical reaction could be quite difficult. Even to experienced, careful researchers, there was no guarantee that conclusions were correct.

Don Antonio was convinced that the glassmaking priest had indeed discovered the secret of transmutation. He put Della Casa to work interviewing Neri's acquaintances to see what could be learned. An expert gold refiner, Guido Antonio Milani, reported to Della Casa that in July 1596, Neri had performed before his eyes a transmutation of base metal into "twenty-four carat" gold. He said he pressed the 20-year-old, who in reluctance, confided that he had learned the secret from a German, who performed the gold transmutation with a "tablet of medicine." The German told Neri the medicine was nothing but the simple quintessence of green vitriol and the method to produce it was described by Paracelsus.

* This post first appeared here in a shorter form on 2 Sept 2013.