OP THE UNITED STATES. 371 



Promiscuous Remarks upon the PrmcipJes of Construction^ the 

 Choice and Trial of Instruments. 



After having; described various instruments, it may not be 

 improper to add sonic general observations upon the subject, 

 which niv experience has enabled me to make. 



The navy, and ships employed in commeice, constitute in 

 England the principal support of the mathematical instrument 

 making, and have established this branch of the arts on a 

 large scale, and contributed to its perfection in the last cen- 

 tury, after tiie invention of tiie reflecting instruments. 



The next encouragement arises from gentlemen who take 

 a pleasure, and rationally amuse themselves in astronomical 

 observations. These amateurs occupy the artists on instru- 

 ments of larger dimensions, of greater accuracy, and more 

 complicated and varied construction. 



The use of instruments for scientific establishments come 

 after these two in the line of influence. The instruments 

 constructed for such purposes are, comparatively speaking, 

 limited as to their number, and last too long to be of much 

 consideration to those who construct them. 



From this results the following state of things in relation to 

 the instrument making in England. 



The instruments suitable for naval purposes and for com- 

 mon surveyitig and levelling fiu'nish the principal support of 

 the artist. From the profits arising from these, he i)ays his 

 workmen, and l)rings up his apprentices. The extent of 

 these two liranches is proved by the numl)crs whicli arc put 

 upon the instruments in regular succession. 



Amateurs requiring Iron) the artist a greater variety, and 

 instruments of a larger size, he is enabled to extend his esta- 

 blishment, and to employ his workmen at a greater variety 

 of work. This prevents their passing itito the class of com- 

 mon mechanics, to which those are really reduced who arc- 



