IMPROVEMENT IN AMERICAN TELESCOPES. 



New- York, March 13, 1855. 

 To the Trustees of the American Institute : 



Gentlemen — Your favor was duly received requesting an ac- 

 count of improvements in telescopes lately manufactured by me; 

 you will find annexed description of two telescopes, one being 

 medium size, the other the largest I have finished up to date. 



I regret not being able to offer at this time the account of per- 

 formance of the Equatorial, now being finished for the Michigan 

 University. This instrument is the largest for which I have re- 

 ceived an order, being 12^ inches clear aperture, 16 feet focal 

 length ; it will be mounted the present month. 



It is unnecessary to add anything to the description annexed, 

 except to state that the 9 inch is not considered quite perfect at 

 present, and it will afford me pleasure to add a full description of 

 its perfective performance in time for your next year's report, if 

 desired. 



Respectfully yours, 



HENRY FITZ. 



Newark, February 23, 1855. 



Dear Sir — In reference to the performance of the achromatic 

 telescope furnished by you with an object glass of 6| inches, it 

 affords me much pleasure to say that it has given entire satisfac- 

 tion, and from a happy combination of good material and skilful 

 finish, it transmits the most delicate light, and gives a correct 

 image. It will bear high powers in a good atmosphere without 

 showing any trace of prismatic color, and still preserving the dis- 



