64 



MECHANICS 



which the motions are to be made, and 

 of lenjfths proportional to the circular 

 arcs through which their extremities 

 are to vibrate. 



If the motions be not on the same 

 axis, the two axes may be connected by 

 almost any of the methods used in 

 transferring continued circular motion 

 from one axis to another. 



Inyfg-. 1 22 is represented a contrivance 

 Of M. Camus, for the purpose of moving 



Fig. 122. 



sieves. A B C D is a table, on which 

 is a plank E F, capable of revolving on 

 the pivots m n. To an arm, s, attached 

 to one of the pivots, a pendulum, R S, 

 is suspended. The first mover gives 

 the pendulum an alternate circular 

 motion, and this gives the plank a vi- 

 brating motion on the pivots. 



There are numerous other contri- 

 vances for accomplishing this change, 

 but our limits preclude us from prose- 

 cuting this subject further. 



CHAP. XIV. Works on Mechanics. 



The treatises which have been pub- 

 lished on this subject, not to mention 

 innumerable detached pieces which 

 have been printed in the transactions 

 of learned societies, scientific perio- 



dicals, &c., Sec., are so numerous, that 

 we cannot pretend to insert here any ca- 

 talogue of them. Nevertheless, we may 

 refer the student, who is desirous of ex- 

 tending his inquiries on the subject, to 

 sources where he may find ample mate- 

 rials for the extension and improvement 

 of his mechanical knowedge. 



To those who are not very familiar 

 with mathematical science, we should 

 recommend Dr. Brewster's edilion of 

 FERGUSON'S MECHANICS. In the se- 

 cond volume of this work, more espe- 

 cially, a vast quantity of valuable in- 

 formation is collected and explained 

 with admirable clearness and simplici- 

 ty. This volume is entirely from the pen 

 of Dr. Brewster, and is by far the best 

 part of the work. The student should 

 be cautious not to consult the old edi- 

 tions of Ferguson, as they contain nu- 

 merous errors. 



The second volume of Dr. Gregory's 

 MECHANICS contains a great quantity 

 of interesting and useful practical in- 

 formation, explained in a very familiar 

 style, and without much mathematical 

 reasoning. The mathematical student 

 will be greatly benefited by the study 

 of the first volume of this excellent 

 work. 



For those who seek an acquaintance 

 with the mathematical theory of Me- 

 chanics, there is a very numerous class 

 of English authors, amongst whom we 

 may mention Bridge, Desaguliers, 

 Emerson, Gravesande, Playfair, Ro- 

 bison, Whewell, Wood, Young, &c. 



The foreign authors, on this sub- 

 ject, are also very numerous: La- 

 place, Lagrange, Prony, Poisson, Be- 

 lidor, Biot, Venturoli, &c. &c. 



