CLOCK. 



on its lower point was suspended from 

 above by a double cord, or cat-gut ; the 

 twisting of this cord, caused by each vi- 

 bration, tended to raise the balance, and 

 its own weight made it descend again, 

 and at the same time turn round in the 

 opposite direction, when the impulse of 

 the first pallet ceased to act on it. The 

 balance was very heavy, as weight was 

 necessary to make it act in the above 

 manner; and this has caused the mode 

 of its operation to be mistaken by many, 

 who supposed that the cord was" merely 

 added to prevent the great friction on 

 the lower end of the arbor, which the 

 weight of the balance would cause. 



The introduction of the spiral spring, 

 as a first mover, instead of a weight, 

 took place about the beginning of the 

 sixteenth century. Mr. Peckett, of Old 

 Compton-street, had one of this construc- 

 tion, which, from an inscription on it in 

 the Bohemian language, was made by 

 Jacob Lech, of Prague, in . the year 

 1525. 



Clocks with the balances above de- 

 scribed, imperfect as they were, gave,, 

 however, some assistance to astronomy. 

 Tycho Brahe had four of them, but of 

 such a massy construction, that a single 

 wheel in one of them, which had but three 

 wheels, contained 1200 teeth, and was 

 three feet in diameter. These clocks 

 continued in use till about 1650, when 

 a new icra in the art commenced, by 

 the application of the pendulum as a re- 

 gulator. 



Bernard, one of the professors of as- 

 tronomy at Oxford, in the last century, 

 lias asserted that the Arabians used pen- 

 dulums in astronomy long before the 

 above period, (as we know that Ricoli, 

 Tycho Brahe, Langrenus, Vendelin, 

 Mersenne, Kircher, Hevelius, Monton, 

 and Galileo himself did,) in a detached 

 state ; but we do not find that any of them 

 used it in conjunction with wheel work. 

 According to professor Venturi, Sancto- 

 rius applied a pendulum to clock-work 

 some time before the year 1625 ; and 

 Becker mentions a native of Switzerland, 

 called Juste Birge, who did the same in 

 1597 ; but these experiments, if really 

 made, never were sufficiently made pub- 

 lic to benefit the world. 



The person to whom mankind is real- 

 ly indebted, for bringing this important 

 discovery into universal notice, is the 

 celebrated Christian Huygens, of Zuy- 

 lichem, who, in his excellent treatise 

 " De Horologio Oscillatorio," has de- 

 scribed the construction of a pendulum 



clock, and proved that he made one L/C 

 fore the year 1658. 



Galileo is supposed to have claims to 

 the priority of the invention of the mode 

 of applying the pendulum to clock-work, 

 and his son Vincentio Galilei is reported 

 (Exper. del Acad. del Cimento) to have 

 made a pendulum clock so early as in 

 1649, at Venice, suggested by his father's 

 discoveries. But it is thought that Huy- 

 gens' method was much more masterly 

 and scientific ; and that the world is not 

 under any obligation to Galileo for the 

 invention ; for, if he really made it, the 

 manner of performing it was kept so se- 

 cret, that Huygens himself never heard 

 of it, though one of the most philosophi- 

 cal characters of his time. There has 

 another claimant appeared of late years 

 for the honour of the invention, on the 

 authority of Mr. Thomas Grignon, of Rus- 

 sel-street, Covent Garden, who produces 

 a well authenticated writing of his fa- 

 ther's, to prove his having seen the in- 

 scription on the great clock, formerly 

 fixed in the turret of St. Paul's, Covent 

 Garden, which ascertained that it was 

 made by Richard Harris, of London, in 

 1641. This clock was regulated by a 

 long pendulum ; and, if the above infor- 

 mation is correct, must have been one of 

 the first made, as it precedes that said to 

 have been constructed by Vincentio Ga- 

 lilei by eight years. Mr. Grignon senior 

 was a very ingenious mechanist, and a 

 man of excellent character, and brought 

 to perfection the horizontal principle in 

 watches, and the dead beat in clocks, 

 which the celebrated Tompion and Gra- 

 ham were unable to effect. These cir- 

 cumstances render his testimony of con- 

 siderable weight. 



Huygens must, however, still be con- 

 sidered as the chief introducer of the in- 

 vention, which no one disputes having 

 been made by him, even though others 

 may be supposed to have made it like- 

 wise, unknown to him. He also invented 

 a clock with a centrifugal regulator, 

 which is contrived to perform its move- 

 ment in a curve that he has demonstrat- 

 ed will render its gyrations isochronal, 

 and which, at least, is worthy of a farther 

 investigation, before it be condemned to 

 an oblivion that it probably does not me- 

 rit. But his discovery of the isochronism 

 of all vibrations made by a pendulum 

 formed to move in a cycloidal curve is 

 that which is the most noted, although it 

 has never yet been really applied to use. 

 Mr. Huygens' method of doing so has 

 been shown clearly to be erroneous, by 

 Mr. Alexander Cummings, in his " Trea- 



