THE KINEMATICS OF MACHINERY. 



ILLUSTRATED BY THE BERLIN COLLECTION OF KINE- 

 MATIC MODELS. 



TWO LECTURES. 



BY PROF. ALEX. B. W. KENNEDY, C.E., OF UNIVERSITY COLLEGE, 

 LONDON. 



T/^e substance of the following pamphlet formed two lectures 

 delivered to Science Teachers at South Kensington during the month of 

 August 1876. They have been recast only so much as to make them 

 intelligible without the aid of the set of models by which they were then 

 illustrated. Any readers' who may wish further to study Rculcaux's 

 treatment of the subject, of which I have attempted here to no'e a few 

 salient points, I must refer to his own " Theoretische Kinema'ik," or to 

 my translation of it, published under the title of " The Kinematics of 

 Machinery. " In th'is work the whole matter is taken up in great detail 

 from the point of view which I have endeavoured to indicate. 



A. B. W. K. 

 LECTURE I. 



MOST of the models used to illustrate this and the follow- 

 ing lecture belong to the Kinematic Collection of the Gewerbe- 

 Akademie in Berlin, and have been designed by Professor 

 Keuleaux, who is the Director of the Academy and a 

 Professor in it. The rest were sent to the Loan Collection 

 by Messrs. Hoff and Voigt of Berlin, and Messrs. Bock and 

 Handrick of Dresden. In essentials there is no difference 

 between the Berlin and the Dresden models. Both have 

 been designed specially for use in instruction in the Kine- 

 matics of machinery. 



I must first try to explain briefly but exactly what I 

 mean by the phrase " Kinematics of machinery." Professor 

 Keuleaux, whose models are before us, defines a machine as 

 " a combination of resistant bodies so arranged that by their 

 means the mechanical forces of nature can be compelled to do 

 work accompanied by certain determinate motions." The 

 complete course of machine instruction followed in some of 

 the continental technical schools covers something like 

 the following ground : 



First, there is the perfectly general study of machinery, 



