PREFACE. Vll 



promote their wishes, nor their children's enjoyment, 

 more than procuring for them an assortment of appa- 

 ratus, whereby they may be able to follow up practi- 

 cally those experiments of which they have read in 

 text books of science, or have seen in lectures. The 

 moderate prices of some of these articles are enumera- 

 ted at the end of this volume. 



In the construction of apparatus, it will be the 

 maker's aim to use the various pieces of apparatus to 

 the best advantage, by adapting them to the perform- 

 ance of as great a variety of purposes and experiments 

 as is possible. 



The writer might enumerate to his patrons a num- 

 ber of diplomas and silver medals received for his 

 Air-Pumps, Galvanic Batteries, Magnetic Machines, 

 Barometers, Theodolites, Magic-Lanterns, Sliders, &c., 

 at various Fairs of different Institutes ; and also the 

 commendatory letters of distinguished Professors in 

 various Colleges and Universities, who are using in- 

 struments of his manufacture ; but having been long 

 established in this business, he trusts that the charac- 

 ter of his instruments is understood, without further 

 reference. 



He would beg leave to notice his improved Magnetic 

 Machines for medical purposes ; and though, unlike 

 many that have followed in his wake, he has not 

 trumpeted abroad the various cures the instrument has 

 accomplished, yet the remarkable cures it has and still 

 is effecting, are beyond question, although he has de- 

 clined to publish cases, from the fact that the most 

 remarkable are among some of the very first families 

 of this city, and elsewhere, to whom it would not be 

 agreeable to have an account of their infirmities seen 

 in print. Let it suffice to say, that this instrument arose 



