NEW BALAMCm . \S9i 



A certificate, dated March 6th, 1805, was received from 

 Mr. Alexander Cuming, of Pentonville, stating that he had 

 seen Mr. Hardy's expansion balance ; that in his opinion 

 it has considerable merit, and promises to act uniformI|l9 

 steadily, and permanently. 



Reference to the Engraving of Mr. William Hardy'' s Perma. 

 nent Balance, Plate IV. Fig. 4, 5/ expressing in indies 

 and d^cim^ parts of an inch, the dimensiom ofihei^verat 



pieces, '■■■ ' •' (■'•' '- 



Fig. 5. A A. Two globes which slide on the cylindrical pjg^re and 

 stems of two upright levers, and are fastened by screws, diagrams of 

 by which the effect of the expansion is increased or ^^"^ "^^ ''*' 

 diminished. ^''^^ 



C C. Two equal and similar screws, by which the watchift-' 

 adjusted to mean time. 



D D. The verge or axis of the balance. 



EE. The combination of the steel bar with the brass 

 bars. 



Fig. 6. S S. The steel bar, whose length is 1.600 



Its breadth .,. , O.'^S^ 



Its thickness ,..,., 0.03^ 



B B. Two similar and equal brass bars, in length 



each 1,470 



In breadth each , 0.078 



In thickness each 0.032 



Length of the two springs formed out of the 



steel bar , , , .,,.,.,. 0.030 



