310 LECTURES TO SCIENCE TEACHERS. 



educational purposes. I have some made in this way of 

 hard wood with brass pins, which are very serviceable for 

 college purposes. It is just the simpler models, which 

 are the most easily made, which are the most useful in 

 instruction. 



I venture to hope that the . treatment of the theory of 

 mechanism illustrated by the models now in the South 

 Kensington Collection, and of which 1 have here endeavoured 

 to set forth some leading principles, may prove valuable in 

 aiding the study and the comprehension of this branch of 

 machine science both to the student and the engineer. 



