In the year 1696 appeared a new kind of koban. The old koban was twenty carats eight and a half, and even ten, grains fine; that is, supposing it divided into twenty-four parts, twenty parts and a half were fine gold.[35] The new koban was thirteen carats six or seven grains fine, containing, consequently, only two-thirds as much gold as the old one, and yet the Dutch were required to receive it at the same rate of sixty-eight mas of silver. The old koban had returned on the coast of Coromandel a profit of twenty-five per cent, the new produced a loss of fifteen or sixteen per cent; but some of the old koban being still paid over at the same rate as the new, some profits continued to be derived from the gold, till, in 1710, the Japanese made a still more serious change in their coin, by reducing the weight of the koban nearly one-half, from forty-seven kanderins (two hundred and seventy-four grains) to twenty-five kanderins (one hundred and forty-six grains), which, as the Dutch were still obliged to receive these new koban at the rate of sixty-eight mas, caused a loss of from thirty-four to thirty-six per cent. From this time the old koban passed as double koban, being reckoned at twice their former weight. The koban of the coinage of 1730 were about five per cent better than the preceding ones; but the Dutch trade continued rapidly to decline, especially after the exportation of copper was limited, in 1714, to fifteen thousand chests, or piculs, and, in 1721, to ten thousand piculs annually. From this time, two ships sufficed for the Dutch trade. For thirty years previous to 1743, the annual gross profits on the Japanese trade had amounted to five hundred thousand florins (two hundred thousand dollars), and some years to six hundred thousand (two hundred and forty thousand dollars); but in 1743 they sunk below two hundred thousand florins (eighty thousand dollars), which was the annual cost of maintaining the establishment at Deshima. Upon this occasion, a “Memoir on the Trade of Japan, and the Causes of its Decline,” was drawn up by Imhoff, at that time governor-general at Batavia, which affords information on the change in the value of the koban, and other matters relating to the Dutch trade to Japan, not elsewhere to be found.[36] It is apparent from his memoir that the trade was not managed with the sagacity which might have been expected from private merchants. The cargoes were ill assorted, and did not correspond to the requisitions of the Japanese. They, on the other hand, had repeatedly offered several new articles of export, which the Company had declined, because, in the old routine of their trade, no profitable market appeared for these articles at the prices asked for them.