BELT POWER TRANSMISSION. LXXXIII. 
BELT POWER TRANSMISSION witH soME NEW FORM OF 
BRAKE ABSORPTION DYNAMOMETER. 
By Hersert E. Ross. 
[Read before the Engineering Section of the Royal Society of N. S. Wales, 
October 20, 1897.] 
Tue history of the use of belting as a power transmitting device 
has apparently no beginning. The custom of the ancient historian 
to chronicle the arts of war rather than the industries of peace, has 
left no record of the earliest part of the subject behind the veil 
of antiquity. Tolerably certain it is, however, that in modified 
forms the use of flexible cords was well known to the pioneers of 
engineering over three thousand years ago. The author has, 
therefore, some hesitation in putting forward a paper on a matter 
which has already received so much attention. 
The subject is however, one eminently suited to discussion, and 
even at this late date, there would appear to be no reliable data 
of the comparative efliciency of all the various kinds of belting 
now in general use. And while leather and rope have received 
much attention, the less common belts, in gutta percha, .india 
rubber, canvas, balata, raw-hide, and hair, have either had no 
reliable values assigned to them, or where coefficients have been 
determined, they are the results of investigation under such vari- 
ous conditions as to render comparison incomplete. 
At the recent Engineering and Electrical Exhibition Buildings 
the author had undertaken a number of tests dealing with the 
classes of belts enumerated. The tests were made under working 
conditions, the same tension, speed and pulleys being used for 
each particular case to establish due comparison. As it was 
necessary to cause the belt to definitely slip on the pulley, a special 
absorption brake dynamometer was designed, a transmissiow 
apparatus not meeting the requirements of the case without means 
of even application of an increasing load. 
