No. 199.] 179 



An emergency of recent occurrence, brought Mr. Fitz conspicu- 

 ously before the public as a manufaclurer of achroinalic telescopes. 

 A series of astronomical observations in the southern hemisphere, 

 were about to be made by direction of Congress. Tliose in charge 

 of the expedition having received information from the successor of 

 Frauenhofer, that it was impossible to make a nine feet equatorial in 

 the time specified, Mr. Fitz volunteered to make an object glass from 

 Guinand's discs, of the same dimensions as that at the High School 

 Observatory at Philadelphia, viz : 6j inches cl^ar aperture, and 6 

 feet focal length, which should be compared with that instrument, 

 and if it proved equal to it, he would charge for it only the cost of a 

 similar lens at Munich, (about $500,) otherwise the Smithsonian In- 

 stitute, which had consented to the loan of theur instrument for the 

 use of the expedition, should have the use of it free of charge until 

 another could be obtained from Germany. Mr. W. J. Young, of 

 Philadelphia, guaranteed to furnish the mountings in the required time, 

 and the glass was made. Professor Kendall, director of the High 

 School Observatory, after trying it by the test proposed, gave the 

 following deckion : 



Philadelphia, May Ist, 1849. 

 My Dear Sir — I had the pleasure to make a trial of the Fitz object 

 glass last evening, and was highly gratified with the result. It was 

 compared with ours (of the same size) upon the Moon, Jupiter, seve- 

 ral double stars, and the bright star Vega, with its companion, using 

 a variety of powers. 



It is my opinion Mr. Fitz bias fully accomplished all he undertook 

 to perform. From this trial I am unable to pronounce which is the 

 better glass — the Frauenhofer doing nothing which was not equally 

 done by the Fitz glass. 



There was one point only about which a doubt arose, viz : color. 

 On fiist looking at Jupiter, I thought there was too much violet about 

 the edge ; but on applying the other (Frauenhofer) object glass with 

 the same eye-piece, I could not discover any improvement, except 

 that which might justly be attributed to the improved state of the 

 atmosphere. 



