He went to Zaandam to see the Greenland whaling fleet, visited the celebrated botanical garden with the great Boerhaave, studied the microscope at Delft under Leuwenhoek, became intimate with the military engineer Coehorn, talked with Schynvoet of architecture, and learned to etch from Schonebeck. An impression of a plate made by him, of Christianity victorious over Islam, is still extant. He made himself familiar with Dutch home life, mingled with the merchants engaged in the Russian trade, went to the Botermarkt every market-day, and took lessons from a travelling dentist, experimenting on his own servants and suite, probably not much to their enjoyment. He mended his own clothes, learned enough of cobbling to make himself a pair of slippers, and, in short, was insatiable in his search for information of every available kind. His work on the frigate whose keel he had helped to lay was continued until it was launched. It was well built, and for many years proved a good and useful ship, braving the perils of the seas in the East India trade. But with all this the imperial carpenter was not satisfied. The Dutch methods did not please him. The ship-masters seemed to work without rules other than the "rule of thumb," having no theory of ship-building from which the best proportions of a vessel could be deduced. Learning that things were ordered differently in English ship-yards, that there work was done by rule and precept, Peter sent an order to the Russian docks not to allow the Dutch shipwrights to work as they pleased, but to put them under Danish or English overseers. For himself, he resolved to go to England and follow up his studies there. King William had sent him a warm invitation and presented him a splendid yacht, light, beautifully proportioned, and armed with twenty brass cannon. Delighted with the present, he sailed in it to England, escorted by an English fleet, and in London found an abiding-place in a house which a few years before had been the refuge of William Penn when charged with treason. Here he slept in a small room with four or five companions, and when the King of England came to visit him, received his fellow-monarch in his shirt-sleeves. The air of the room was so bad that, though the weather was very cold, William insisted on a window being raised.