Reviewed by Alvaro Martinelli Appalachian State University

It is well known that during the 14th century the city of Pisa was a major center for the manufacture of and commerce in leather. There is ample evidence that, at the time, there existed fundamental basic conditions for the creation and development of a tanning industry, including an ample supply of water, easy access to myrtle and chestnut groves, and a reliable source of livestock from the country. In addition, the close commercial relationship with the Saracens from North Africa had further stimulated the development of this industry since the 12th century. In fact, we have knowledge that in 1156 the sovereign of Tunis exempted all Pisan merchants from the payment of export duties on alum, a basic tanning ingredient.

Additional supporting evidence enhancing the position of Pisa is to be found in a ledger discovered by the author among the documents preserved in the State Archives of the city. The manuscript is classified as Book of Debit and Credit, and in it the merchant-tanner, Bartolomeo di Tingo, recorded all the costs for the purchase of hides and manufacture and sale of leather for the period 1384-1388. By following closely the allocation and classification of different costs, one may perceive that the basic industrial process used by Bartolomeo was not much different from other various techniques adopted until the second half of the 19th century when great progress was made by the introduction of the tanning drum and the use of chromium salts.

The main operations were usually performed by the river Arno with rather inexpensive tools, such as knives, beams, buckets and vats. Before starting the long and tedious tanning process, hides were first rounded into different sections according to thickness. Imported hides were subjected to a prolonged soaking and subse-quently treated with lime in order to separate the corium from the epidermis and to destroy the root hair. The hides were later stripped of flesh, rinsed and repeatedly scrubbed to eliminate any trace of lime and to facilitate the penetration of tanning ingredients, such as myrtle, alum and oil.

The actual tanning process took place in big vats full of hot water, where hides were soaked in a solution of minced myrtle, and sometimes alum was added, to allow what it was called a “double tanning,” since the treatment with myrtle was known as vegetal dressing, and the treatment with alum as mineral dressing. The tanning in the myrtle was assimilated by the derma through an osmotic process, making the hides strong, flexible and water repellent. Finally, the finished product was allowed to dry up “in the loft” or “in the field.”
By the name of addobbo, or dressing, Bartolomeo indicates all the various operations that follow the fleshing until the hides were soaked into the vats. In all, we may count eight dressings that lasted from 24 to 95 days, with an average time span of 35-40 days per dressing. Since different groups of operations were performed at the same time, it appears that the labourers were performing repeti-tive tasks, as if a very slow assembly line was taking place.

Bartolomeo carried on his business in association with other partners: with Andrea di Puccino, leather-seller, until April 1385; with Dato di Borghese, tanner and merchant, from June 1385 to October 1386; with Piero Pancando, merchant, from February 1387 to July 1388. All the accounts are in paragraph form. The monetary unit is the lira of 20 soldi or 240 denari and the florin of 70 soldi, with the florin valued at three and one half liras. In the ledger there is record of the costs for the purchase of the hides, raw materials used in the tanning process, direct labour, and revenues from the sale of the finished product.

For the first association with Andrea di Puccino, there is no record of costs, but only revenues for the sale of leather in inventory: 450 backs still unfinished and 650 Berber skins were still unsold. The sale of 641 backs and 639 white bellies originated revenues of L. 4,215. This association is in a liquidation stage, and there is no reference to profits or losses. Only for the second association with Dato di Borghese is there reference to the capital contributed by the partners and the allocation of profits. The initial contribution of Dato was of F. 95 s. 12, and his final balance was of F.176 s. 9 d. 10, with a rate of return of about 85%. The total cost for 152 hides amounts to L. 498.2.7; costs for labour, raw materials and transportation amount to L. 129.16.11. Sales are recorded in four different lots of merchandise, for a total of L. 787.8.9.

For the third association with Piero Pancando, there is no record as to the distribution of profits nor the capital contribution of the two partners, who purchased a total of 1286 hides at a cost of L. 4,615. This cost includes, in separate accounts, the purchase price, transportation by sea and by land, weighing, brokerage: loading and unloading. Additional costs were: labour, L. 501.9.8; myrtle, L. 656.17.6; lime, L. 25.1.10; firewood, L. 64.13.6; gratuities, L. 4.2.5, for a total of L. 1,286.11.3. Total revenues for L. 7,084 were generated by the sale of 685 backs, 1,304 bellies and 590 shoulders.

Based on these data, it appears that the average cost of a raw hide was of s. 65 when imported from a foreign country, and s. 100 when bought from a local butcher. If we add all the costs for material and labour, the final total cost of a tanned hide amounts to s. 79-122, whereas its selling price was of s. 117-150 if tanned with alum, and s. 168-201 if tanned with myrtle. The cost of production may be broken down as follows: raw hides 77.84%, tanning ingredients 13.29%, labour 8.45%, and rent for the shop .42%. The total cost of a finished hide amounts to 84% of its revenue, with a profit of 16%.

If we roughly assume that one soldo is more or less equivalent to two dollars of today (although it is almost impossible to make a rational comparison of the two monetary units, due to the great disparity in the purchasing power of money and in the standard of living), we may conclude that raw hides were at least ten times more expensive and tanned hides about seven times more expensive as they are today. The disparity in values was probably due to the relatively low incidence of the cost of labour on the total cost of the finished product.
In this study, the author gives a detailed analysis of the cost ac-counting system implemented by a 14th century businessman. Bar-tolomeo, somehow, reflects the personality and aspirations of a typical Medieval entrepreneur dominated by the idea of gain, in his belief that exactitude and clarity were indispensable in the business world.