1895.] The Kinematics of Machines. Ifi7 



The distances between the junctions were BM = 2'57 cm. and MT 

 2'6 cm. Hence by the formula of 2, 



73-1 -=-2-6 _ 28a 0-91 

 '" 



_ 



, M) 79-0-7-2-57 307 



Aberdeen granite : 



i?(T) = 81'l. 



u(M) = 145'6. 

 v(B) = 214'6. 



The distances between the junctions were BM = 1*9 cm. and 

 MT = 2-0 cm. 



64-5-7-2-0 32'2 _ 

 69-0-7-1-9 ~ W~3 ~ 88> 



13. Thus we see, that for slate, with, lines of flux parallel to 

 cleavage planes, the mean conductivity in the range from 123 C. to 

 202 C. is 91 per cent, of the mean conductivity in the range from 

 50 C. to 123 C., and for granite, the mean conductivity in the range 

 from 145 C. to 214 C. is 88 per cent, of the mean conductivity in 

 the range from 81 C. to 145 C. The general plan of apparatus, 

 described above, which, we have used only for comparing the con- 

 ductivities at different temperatures, will, we believe, be found 

 readily applicable to the determination of conductivities in absolute 

 measure. 



II. " The Kinematics of Machines." By T. A. HEARSON, 

 M.Inst.C.E., Professor of Mechanism and Hydraulic Engi- 

 neering, Royal Indian Engineering College, Coopers Hill. 

 Communicated by Professor COTTERILL, F.R.S. Received 

 March 19, 1895. 



(Abstract.) 



In this paper the author regards a machine as an embodiment of 

 a movement. The method of construction and the proportions of the 

 parts are not taken into consideration, except so far as may be neces- 

 sary to explain the conditions requisite for the kinds of motions with 

 which they are supposed to be endowed. All other considerations 

 relating to form and proportion are omitted, as belonging to the sub- 

 ject of machine design. Neither does the author take account of the 

 forces which actuate and oppose the movement of the machine, such 

 matters belonging to the subject Dynamics of Machines. 



The object of the paper is to analyse the movements only, and to 



