﻿Mr. A. Sharp on an Harmonic Analyser. 



121 



He has also introduced a celluloid ring below the sphere, 

 which on being raised presses the sphere against a similar 

 ring above, thus preventing any damage to the integrating 

 apparatus when the instrument is not being used. 



Note. — At the request of Herr Coradi I add the statement 

 that the idea of the new integrating apparatus, consisting of a 

 sphere with two recording-wheels at right angles to each 

 other, is not his own, but is due to Herr Max Kiintzel, of 

 Charlottenhof, near Konigshutte in Silesia. Herr Kiintzel 

 invented the arrangement for an instrument designed to 

 determine the coordinates of the vertices of a polygon, and 

 submitted his design to Herr Coradi for the construction of 

 such an instrument. 



IX. Harmonic Analyser, giving Direct Readings of the Am- 

 plitude and Epoch of the various constituent Simple Harmonic 

 Terms. By Archibald Sharp, B.Sc, Wh.Sc, A.M.I. C.E.* 



LET the curve (fig. 1) be that represented by the equation 

 y=f(x), the scale of abscissae being such that the 

 period is iir. Suppose a wheel W to roll on the paper 



1 F 



tz - 



i 





> 



i§r 





\^' 



"^N 







\i~ _ 







J 



.— iV* 



^JTZ. - - 





-M 



V* 



*j 



'..-IP. 



SL-* -_->!_ 



F7C. / 



(fig. 2), and to be connected with a tracing-point P (fig. 1) 



in such a manner that as P moves uniformly in the direction 



* Communicated by the Physical Society : read April 13, 1894. 



