96 . Mr. H. Tomlinson. The Influence of 



Table I. 



ivietai. 



lx n, 

 position vertical. 



I x n, 



position horizontal. 





192,650 



195,567 





136,410 



141,700 





136,410 



140,067 





140,500 



142,200 





243,900 





261,700 





The results shown in this table are far from being satisfactory, and 

 the numbers in the third column differ from those in the second 

 column by amounts which are in all cases considerably larger than the 

 differences in the values of Z x n, as determined for different lengths 

 of the same metal, either in the vertical or the horizontal position. 



Final Method of Experimenting. 



Though the notes obtained by rubbing the wires longitudinally 

 were fairly clear and well defined when the wire was arranged accord- 

 ing to either of the above methods, yet the divergence of the results 

 given above was such as to induce the author to try a third method, 

 which, when certain corrections have been applied for want of rigidity 

 of the masses to which the ends of the wire are clamped, seems to be 

 capable of considerable accuracy. In fig. 1, Plate 2, AB is a hollow 

 box,* made of wooden planks half an inch thick. The length of the 

 box is 600 cm., the breadth 10 cm., and the depth 10 cm. At one 

 end of the box is a pulley C, round which the wire passes to the 

 scale-pan S. D and B are two pairs of stout blocks of wood, each of 

 which can be firmly clamped to any part of the box by a pair of very 

 stout wooden screws. f The stout blocks of wood carry each an iron 

 clamp, by which the wire can be secured, and the blocks of wood 

 together with the screws are ail well insulated from the box by means 

 of thick layers of baize M, so that the vibrations of the wire cannot 

 be imparted to the box. J The wire is first clamped to the wooden 



* There is no advantage in having a hollow box ; a solid piece of wood or metal 

 of sufficient stoutness would answer the purpose equally well, 

 f Only one of each pair of screws is shown in the figure. 



% This the author found to be a matter of some considerable importance, as the 

 note was very much clearer and purer when the blocks were insulated from the box 

 than when they were not. A rather curio U3 case of synchronism occurred in one of 

 the earlier experiments where the blocks were not insulated from the box. An iron 

 wire had been arranged to give, as far as could be judged by the note, 512 vibrations 

 per second. The note was, however, very far from clear; but by shortening or 



