He placed it in a sort of moveable frame, somewhat resembling what the sailors call a 'compass jumble,' but much more artificially and curiously made and arranged.

In this state the chronometer was tried from time to time in a large barge on the river Humber, in rough as well as in smooth weather, and it was found to go perfectly, without losing a moment of time.
Such was the condition of Harrison's chronometer when he arrived with it in London in 1735, in order to apply to the commissioners appointed for providing a public reward for the discovery of the longitude at sea.

He first showed it to several members of the Royal Society, who cordially approved of it.

Five of the most prominent members--Dr.
Bailey, Dr.Smith, Dr.Bradley, Mr.John Machin, and Mr.George Graham--furnished Harrison with a certificate, stating that the principles of his machine for measuring time promised a very great and sufficient degree of exactness.

In consequence of this certificate, the machine, at the request of the inventor, and at the recommendation of the Lords of the Admiralty, was placed on board a man-of-war.
Sir Charles Wager, then first Lord of the Admiralty, wrote to the captain of the Centurion, stating that the instrument had been approved by mathematicians as the best that had been made for measuring time; and requesting his kind treatment of Mr.Harrison, who was to accompany it to Lisbon.