Note 8 — Chapter VIII

The reckoning of our Castilian marco in accordance with the laws which prescribe its form originates with grains of wheat. The weight of thirty-six grains is computed as an adarme; sixteen of these make one onza, and sixteen onzas one libra; twenty-five libras make one arroba, and four arrobas the greatest weight, which is a quintal. Laying aside the declarations that wheat may not be used to supplement the established weights of metal (a custom of various ports and provinces), it appears that, with only this information, a corresponding standard could not be made in Manila, since it was deficient in that species of wheat to which the laws refer, and although there is likewise a harvest of these grains in Philipinas, and quantities of wheat are also brought hither from China—some [having grains] of larger size and less weight, and others that are small and compact—the variety in them arouses great uncertainty, for a matter so delicate. Certain it is that, whatever might be taken for the origin [of this computation], it must produce a system corresponding [to the Castilian]; and, by being made general for both buying and selling goods, it would furnish due fulfilment to the form prescribed in the respective laws. But, as that system would always be deemed more conformable to the intention of the laws the more [nearly] its ratios were identical [with those of Castilla], and when the variety of weights and measures (which, considering the laborious nature of mercantile operations and the interests at stake in them, is at times a very onerous burden) in the provinces with which trade is carried on should be reduced to a common basis: as these islands possess the trade with Nueva España, the importance which any unforeseen disagreement might indicate could not be overlooked. This consideration led to the most careful investigation of the basis to which the matter could be reduced; and, in order to find the system equivalent [to that of Castilla], various standards were adjusted to one another, from which a safe conclusion might be drawn. Accordingly, grains of lentils (which give name to the marco8 of Aragon) were taken, and search was made for grains of wheat whose weight would correspond, with the difference of one-eighth. The same was done with grains of alberjones9 (from which sort originated the marco of Venecia), and it was found that the weight of each one agreed with that of four grains of separated wheat. The same was done with chick-peas [garvanzos] (from which the marco of Flandes took its origin), and it was found that one of these weighed the same as thirty-six grains of wheat. As a result, through the weight of the aforesaid legumes, in the respective ratios of the marcos of Aragon, Venecia, and Flandez, and the corresponding weight of the grains of wheat, to which reference is made by our Castilian marco, sufficient basis was formed on which to make the standards [of weight]. In fact, they were made by this rule, weights of metal being made which should correspond to one, two, and three grains of wheat, and which together should weigh as much as the weight which is called a grano of silver; another of one, two, and three granos of this sort, the aggregate of which should be equivalent to the weight of one adarme; and by this [were established] the rest of the weights corresponding [to those of Castilla], as far as that one which would contain one onza, from which resulted the greater weights of libras and arrobas. Metal weights were also made equivalent to half a grain of wheat, and to one-fourth, one-eighth, one-sixteenth, and one-thirty-second of a grain, which last is the same as the eleven hundred and fifty-second part of the adarme; or, if this latter weight were divided into so many and small parts, each one of them would alike agree with the weight made for the thirty-second part of the grain of wheat.