294 INVENTION OF CHRONOMETERS, &C. 



consequently the detent with pivots, which its universal use in this country 

 pie erable. seems to prove, that property, combined with the economy in the 

 manufactory, must secure to the mechanism in question, the 

 character of an improvement in the construction of tmie- 

 keepers. 

 The spring de- To whom are we indebted for the invention of the spring 

 re\'h?inven-^'' '^®'^^"* • '^^^^ general opinion attributes it to the late Mr. 

 tion of Arnold, Arnold; and wc do not see any reason of sufficient weight to 

 shAvv^clSsVt. ^^f"^^ h'"^ ^^^^t merit. Mr. Earnshaw has claimed it in his 

 own favour ; but Mr. Arnold's labours have, at least, the advan- 

 tage of priority; and the strength of this advantage, not having 

 been done away by any proofs, which in our opinion can be 

 esteemed satisfactory, must decide, our judgment in the pre- 

 sent case, as in the like controversies upon other points, which 

 have been considered in the course of this inquiry. The contri- 

 vance of the locking spring, or spring detent, therefore, appears 

 to us to be due to the late Mr. Arnold. With regard to this 

 mechanism, it is also worthy of remark, that the invention is 

 It Ts not a fo- entirely English, not a single passage existing in the writings of 

 tfon" '"^^"' the French authors, by which any one of them might claim it 

 with reason, or even plausibility. The first mention of any 

 thing like the locking spring, to be found in foreign publications, 

 is the detent without pivots, given by F. Berthoud in his Supple^ 

 ment au Traite des Horloges Marines (Fig. 6, Plate IV.) ; but 

 that book was published in 1787, that is five years after Mr. 

 Arnold had taken out his patent, and when many watches upon 

 that construction had been in circulation. We cannot, there- 

 fore, allow him the credit of this thought; nor do we find, that 

 other French artists have availed themselves of that hint, to 

 carry the spring detent to the great degree of simphcity, which 

 it has attained in this country. 

 The modern A little after the invention of the detached escapement, the 



discovery, or Jsochronism of the vibrations of the balance, by means of 

 re-d)scovery, ot . i /• 



theisochron- the spiral spring, was, if not newly discovered, at least perfect- 

 ism of the VI- gj ^^^ brought into seneral notice; and that principle added 

 brations by the *=> ° ' . . , . 



balance spring, a great value to the detached escapement, while this mechanism 



secured tlie utility of the principle, by offering the species of 

 insulated balance which it required. From some theories and 

 experiments long known to the world, it would appear that the 



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