Thomas Tompion, the eminent watchmaker of Water Lane, Fleet Street. Graham formed a very high estimate of his pupil's ability. On the expiration of his articles Mudge took lodgings, and continued to work privately for some years. One of the best watchmakers of the time for whom he constantly worked was Ellicot. When the latter was requested to supply Ferdinand VI of Spain with an equation watch, Mudge was entrusted with the construction of the instrument, although Ellicot's name was attached to it when finished, in accordance with the usual practice. Subsequently, when explaining the action of the watch to some men of science, Ellicot had the misfortune to injure it, and, being unable to repair the damage himself, he had to return it to Mudge. This circumstance reached the ears of the Spanish king, who had a mania for mechanical inventions, and he employed Mudge to construct for him a much more elaborate chronometer. This watch, which was made in the crutch end of a cane, struck the hours and quarters by solar time, and the motions of the wheels at the time of striking were revealed by small sliding shutters. The king constantly spoke admiringly of the maker.
Mudge had been admitted a free clockmaker on 15 Jan. 1738. In 1750 he entered into partnership with a former fellow-apprentice, William Button, and took the old shop at No. 67 Fleet Street, where the firm constructed for Smeaton a fine watch, with a compensation curb, and also made Dr. Johnson his first watch in 1768. In 1760 Mudge was introduced to the Count Bruhl, envoy extraordinary from the court of Saxony, who henceforth became a steady patron. During his partnership he also invented the lever escapement, the first instrument to which this improvement was applied being a watch made for Queen Charlotte in 1770.
In 1765 Mudge had published 'Thoughts on the Means of Improving Watches, and particularly those for the Use of the Sea,' and in 1771 he quitted active business and retired to Plymouth, in order to devote the whole of his time and attention to the improvement of chronometers designed to determine, with the aid of the sextant, the longitude at sea. The improvement of timekeepers for this purpose had long been an object of solicitude with the government, and a reward of 10,000l. had been offered by parliament in 1713 for a chronometer which should determine the longitude within sixty geographical miles ; if within thirty geographical miles, twice that reward was offered. John Harrison (1693-1776) [q. v.] ultimately obtained the larger reward in 1773 for a chronometer which only erred four and a half seconds in ten weeks. Further rewards were, however, offered in the same year for a more perfect method, and Mudge felt confident that he could attain the degree of exactness required. In 1776 he was appointed king's watchmaker, and in the same year he completed his first marine chronometer. He submitted it to Dr. Hornby, Savilian professor of astronomy at Oxford, who tested it, with satisfactory results. It was then committed to Nevil Maskelyne [q. v.], the astronomer, for some more protracted tests at the observatory (1776-7). The board of longitude in the meantime gave Mudge five hundred guineas, and urged him to make another watch in orderto qualify for the government's rewards, the terms of which required the construction of two watches of the specified accuracy. Mudge forthwith set about making two more timekeepers, which were known as the green and blue chronometers (one of them is still preserved in the Soane Museum, and is in going order). These were submitted to the same rigorous tests as the first, but, like it, they were described by the astronomer royal as not having satisfied the requirements of the act. A controversy ensued, in which it was stated that Maskelyne had not given the timekeepers fair trial, but that they had gone better in other hands both before and after the period during which they had been under his observation. Mudge's case was strongly urged in a pamphlet issued by his eldest son, entitled 'A Narrative of Facts relating to some Timekeepers constructed by Mr. T. Mudge for the Discovery of the Longitude at Sea, together with Observations upon the Conduct of the Astronomer Royal respecting them,' London, 1792. Maskelyne retorted in ' An Answer to a Pamphlet entitled A Narrative of Facts . . . wherein . . . the Conduct of the Astronomer Royal is vindicated from Mr. Mudge's Misrepresentations' (1792), and the controversy closed with the younger Mudge's ' Reply to the Answer . . . to which is added . . . some Remarks on some Passages in Dr. Maskelyne's Answer by his Excellency the Count de Bruhl' (1792). Mudge was supported throughout by M. de Zach, astronomer to the Duke of Saxe-Gotha, who had observed the variations of the first of Mudge's chronometers for two years, and by Admiral Campbell, who carried the chronometer on voyages to Newfoundland in 1785 and 1786 respectively. This chronometer was afterwards stated by Thomas Mudge junior to vary less than half a second per diem. It is curious that Harrison entertained similar grievances against Maskelyne, and it waa currently supposed that the astronomer
