194 



THE AMERICAN MONTHLY 



[October, 



then set up my instrument and showed 

 him, as the first object, the scales of 

 the Podura. He almost instantly ex- 

 claimed, with warm earnestness, ' I 

 am sure that will show the hippocatn- 

 pus.' I replied that I feared not, as 

 I had not one of my best highest 

 powers with the instrument. Prof. 

 Bailey insisted upon finding the ob- 

 ject on the slide, and the instant his 

 eye caught it he exclaimed : ' It 

 shows it beautifully — this is a perfect 

 treat.' I then looked at it, and must 

 confess almost instantly lost my rev- 

 erence for the ' English test-object 

 par excellence.' " 



Besides resolving the N. hippocam- 

 pus, which was then the most diffi- 

 cult test-object in use, the new ob- 

 jective revealed markings on numer- 

 ous other frustules which Prof. 

 Bailey had not succeeded in resolv- 

 ing by any other objective. 



The statements of this letter were 

 fully endorsed by Prof. Bailey in a 

 letter to Dr. Torrey ; he pronounced 

 the microscope " decidedly superior 

 to Chevalier's." Among the advan- 

 tages claimed by Mr. Spencer for 

 this instrument, was an increased an- 

 gle of aperture for the objectives — 

 the -^-inch having an angle greater by 

 about one-half than the Chevalier, 

 and the higher power nearly double 

 that of the corresponding one of that 

 maker. Also the field was larger in 

 'the Spencer instrument — the power 

 of 350 had a field more than double 

 that of the power of 325 by Che- 

 valier. 



This microscope immediately at- 

 tracted the attention of scientific 

 men, and it was acknowledged that 

 Spencer's objectives were superior to 

 all others. A short account of the in- 

 strument was given in the New York 

 Literary World for October, 1847, 

 and a more complete one was pub- 

 lished in the American Journal of 

 Science and Arts during the next 

 year.* 



No doubt much of Mr. Spencer's 



* Second Series, Vol. V, 1848. 



success is due to the conscientious 

 care with which all his work was done; 

 but it should not be forgotten that he 

 was an enthusiast in his work, and 

 therefore able to overcome many ob- 

 stacles, so, when he found that he 

 could not obtain such optical glass as 

 he desired, he began experimenting 

 in the manufacture of glass, and for 

 many years he used glass of his own 

 production. 



About the year 1850 (or 185 i) 

 Spencer made a -j^-inch, which he 

 said had an aperture of " as near 

 180° as can be obtained," and this 

 was regarded as a great triumph for 

 the American optician, who had al- 

 ready proved that a limit of 135°, 

 which had been fixed by some, was 

 far too low. Mr. Spencer's later work 

 is so well known that we need not 

 allude to it here. 



Charles A. Spencer was born at 

 Canastota, N. Y., in the year 1813. 

 He was educated at the Cazenovia 

 Academy, from which he graduated ; 

 afterwards he spent one year at Ho- 

 bart College. He lived at Canastota 

 until about six years ago, when he 

 went to Geneva and became associat- 

 ed with the Geneva Optical Company, 

 but soon separated from that firm, 

 and in company with his two sons 

 produced objectives which made the 

 name of C. A. Spencer & Sons fam- 

 ous throughout the world. But fail- 

 ing strength rendered him incapable 

 of steady application to his work ; 

 during the past few years he did little 

 more than superintend the labor of 

 others, and perhaps the latest pro- 

 ducts of the manufactory were mainly 

 due to the skill and close application 

 of his son Herbert. 



Mr. Spencer died at his residence 

 in Geneva on Wednesday evening, 

 September 28th, 1881. He was modest 

 and always allowed his work to speak 

 for itself — his reputation rests upon 

 what he has done not upon what he 

 has said. His death is sincerely 

 mourned by many friends. 



Looking back over the short period 

 of fifty years, we can almost say that 



