NEW BALANCE. X23 



centrifugal force, the weight is thrown inward by the 

 elasticity of the rim. 



My weights or spheres are firmly braced in every degree 

 of temperature, and consequently not influenced in the 

 smallest degree by any change in their centrifugal forces ; 

 therefore, in every respect, this balance may be considered 

 as permanent. 



The great difficulty in constructing a balance, and in T^g ^g^y ^,J^. 

 applying the direct expansion of metals, is to contrive it 90 lance preserver 

 as that it shall preserve its equilibrium in every degree of "*^"'"'°' 

 temperature, and also admit of having all its parts made 

 perfectly equal and similar by mechanical means. Both 

 these important problems I have solved, by the introduction 

 and application of a different principle from any yet used 

 in the cqnstruction of the balance of a timekeeper ; and 

 I am fully satisfied, from a variety of experiments which 

 I have made, that by this total change of system, I have 

 made a higher step towards the perfection of time-keepers, 

 than has been effected by any other means that have come 

 within my knowledge. 



Letter to the Secretary, by the Editor'^. 



Dear Sir, 



I take the liberty to express my opinion of the compen- 

 sation-balance, which Mr. Hardy has submitted to the 

 consideration of the Society of Arts. I think it a very 

 excellent contrivance ; the following are some of the 

 reasons which, I presume, will entitle it to the approbation 

 of that respectable Institution. 



1st. — The invention of confining the flexure of the steel Advantages of 

 bar to a small part near the end is new, and no less re- JM^r. Hardy* 

 markable for its ingenuity and simplicity, than for the "^*^* 

 steady effect it produces. 



2d. — The whole combination is particularly firm; and 

 as the workmanship depends upon faces which are either 



• The useful and patriotic society to which this letter was addressed 

 through their Secretary, is always ready to receive communication* 

 rcspectiqg the subjects proposed for their coasideration.— N 



M 2 ' pisy-n 



