Ford Madox Brown, The Manchester Murals:
"The Proclamation Regarding Weights and Measures, 1556."
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 caused 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.
"Ford Madox Brown, ""The Manchester Murals: The Proclamation Regarding Weights and Measures, 1556"" (Michoro ya Manchester: Taarifa Kuhusu Uzito na Vipimo, 1556) " Kwa sababu ya kuwa na viwango vya juu vya kupima, kilo moja ya Florentine ilihesabiwa kuwa tofauti na kilo moja ya maeneo mengine kama vile Massa na Piedmont. Kila jiji la Italia lilikuwa na viwango vyake vya uzito na kiasi ambacho wafanyabiashara walitarajiwa kushikamana nacho. Kwa kweli, tofauti hizo zilikuwa ndogo na huenda zilihusishwa zaidi na siasa kuliko usahihi. Tangu enzi za kale, wafanyabiashara wa bidhaa waligundua kwamba ikiwa seti yao ya uzito iliyotumiwa katika mauzo ilikuwa chini kidogo ya kiwango, kwa muda uhifadhi ungepatikana, sio kubwa lakini muhimu. Miji pia ingeweza kutumia kanuni hiyo; ilifaa kuweka viwango vilivyo juu au chini kidogo kuliko miji jirani ambako mtu alikuwa akinunua au kuuza bidhaa mbalimbali. Kwa kweli, tofauti hizo hazikuwa kubwa kwa sababu tu biashara yenye mafanikio ilihitaji kwamba wanunuzi na wauzaji waweze kukubaliana na kufanya mapatano. Hata katika nchi mbalimbali za Ulaya na Mediterania, tunapata makubaliano ya karibu katika vitengo mbalimbali vya kipimo. "Mtafsiri wa kwanza wa Neri, Christopher Merrett, alitoa tafsiri ya Kiingereza ya ""L'Arte Vetraria"" mwaka 1662." "Mwanzo wa kitabu cha Neri, kitabu cha ""Six Pints of Water"" kinaonyesha kwamba Neri alikuwa na uwezo wa kutengeneza ""libre sei di acqua"" (mafuta sita kwa kila lita) kwa kutumia pesa za kawaida." Mwanzoni, inaonekana ajabu kuwa kugeuza uzito katika kiasi, lakini hii ilikuwa sahihi kabisa. Wakati huo huko Uingereza, lita moja ilifafanuliwa kuwa kilo moja (ya divai au bia). Mara nyingi kila mmoja wa mabaharia alipewa lita moja ya pombe kwa siku; pia lita hiyo ilikuwa sehemu ya nane ya futi ya kiunzi. (Kilamu ya mraba ilikuwa sawa na galoni moja.) Mfumo huu ulikuwa rahisi sana kwa makampuni ya usafirishaji ambao walihitaji kuhesabu kiasi cha mizigo na ballast katika meli zao za biashara na pia kuepuka uasi uliosababishwa na kukoma kwa bia baharini. Baadaye, Mfalme George wa Nne aliongeza kiasi cha maji kutoka galoni moja hadi galoni moja, na hivyo kuondoa wazo la Merritt. Mabadiliko mengine yalikuwa na matatizo zaidi. Kwa kuwa vipimo vya hakika vilitofautiana kutoka mahali hadi mahali, ukubwa wa kundi ungeweza kuwa mkubwa au mdogo; si jambo la kuhangaikia sana. Hata hivyo, uwiano ulikuwa wa maana sana katika mapishi. Kama vile katika kuoka keki, kundi zima la glasi laweza kuharibiwa kwa kubadilisha uwiano wa vifaa. Mfumo wa Trojan na mfumo wa Apothecary ulitegemea pauni ya pauni kumi na mbili wakati mfumo wa Avoirdupois ulitumia pauni ya pauni kumi na sita. Wakati Merritt alipokuwa akifanya tafsiri yake, Uingereza ilikuwa chini ya mfumo wa avoirdupois tangu Henry wa Nane (ingawa, mwaka wa 1588, Elizabeth wa Kwanza alifanya mambo kuwa magumu zaidi kwa kuongeza uzito wa paundi kwa asilimia ishirini na moja). Wakati huohuo, Florence na sehemu kubwa ya Ulaya ziliendelea kutumia mfumo wa Troya. Watengenezaji wa glasi Waingereza waliotaka kutumia kitabu cha Neri kama hati ya kazi wangehitaji kujua ni mfumo gani wa kutumia. Tafsiri ya moja kwa moja ya Merrett iliongeza kizuizi ambacho kingewatatanisha wale wasiojua. Ili kufikia muundo wa Neri chini ya mfumo wa avoirdupois uliokuwapo, wasomaji wa Merrett wa Uingereza waliohitaji kupunguza kwa 1 5 kiasi kilichoelezwa katika paundi, na kuongeza kwa 1 15 kwa ounces. Ujumbe huu ulionekana kwa mara ya kwanza mnamo Septemba 18, 2013.