Halley, to whom he communicated his plans of building a fleet, and in
general of introducing the arts and sciences into his country, and
asked his opinion and advice on various subjects; the doctor spoke
German fluently, and the Tzar was so much pleased with the
philosopher's conversation and remarks, that he had him frequently to
dine with him; and in his company he visited the Royal Observatory in
Greenwich Park.

As in Amsterdam, so also in London, he visited the manufactories and
workshops of various artificers, and purchased whatever he deemed
either curious or useful; and among other things "he bought the famous
geographical clock made by Mr. John Carte, watchmaker, at the sign of
the Dial and Crown, near Essex-street in the Strand, which clock tells
what o'clock it is in any part of the world, whether it is day or
night, the sun's rising and setting throughout the year, its entrance
into the signs of the zodiac; the arch which they and the sun in them
makes above or below the horizon, with several other curious
motions."[14] He was very curious in examining the mechanism of a
watch, and it is said he could take one of these ingenious machines to
pieces, and put it together again, before he left London.

[14] Postman, No. 136.

The king had promised Peter that there should be no impediment in his
way of engaging, and taking with him to Russia, such English
artificers, and scientific men, as he might desire, with such
instruments as their trade or profession required.

The number of all descriptions of persons that finally left England,
when the Tzar returned to Holland, is stated to have been nearly as