424 8KC. 11. ASTRONOMY. 



1859. Specimen Impression made with the small spec- 

 trograph. Prof. H. W. Vogel, Berlin. 



b. PHOTOGRAPHS. 



1860a. Photographs of the Arrangement for Obtaining 

 Solar Photographs, by means of Huyghen's lens of 123 feet 

 focal length. J. Norman Lockyer, F.R.S. 



1861. Photographs of the least refrangible end of the spec- 

 trum, by iron and other processes. Capt. Abney, R.E., F.R.S. 



1862. Daguerreotype of the Total Eclipse of the Sun 



of the 28th of July 1851, taken at the Observatory of Konigsberg. 



Dr. Schur, Strassburg. 



During the eclipse four photographs were taken. This one was formerly 

 in the possession of Prof. A. C. Petersen, late Director of the Observatory 

 in Altona, and after his death it became the property of his grandson, the 

 exhibitor. 



1863. Photographs of the Sun, taken with the Kew helio- 

 graph, and one of a scale put up for determining the amount of 

 distortion produced by the instrument. 



Kew Committee of the Royal Society. 



The Kew Observatory possesses a set of these negatives, extending from 

 1858 to 1872, and it is now employed in accurately determining from them 

 the positions and areas of the spots observed during the 10 years 1862-1872, 

 during which they were uninterruptedly obtained. 



They are photographed on collodion fibrine, and developed by pyrogallic 

 acid. 



The sixth picture in the frame is one of a series of views taken, of a 

 standard scale, suspended to one of the galleries of the Pagoda in the Kew 

 Gardens, distant 1,500 yards, for the purpose of determining the optical 

 distortion of the heliograph. 



930a. Photo-engraving of a Group of Sun Spots. 



W. De La Rue, D.C.L., F.R.S. 



Made from an original solar negative obtained with an equatorial reflector 

 of 13 inches aperture, 10 feet focus, and a secondary magnifier attached to 

 the eye end of the telescope. The negative being on a scale of 4 feet to the 

 Sun's diameter. 



1914d. Collection of Photographs, illustrating various 

 expeditions for observing Total Eclipses of the Sun. 



J. Norman Lockyei*, F.R. S. 



1914e. Three enlarged Photographs of the Moon, by- 

 Mr. Rutherfurd, of New York. J. Norman Lockyer, F.R.S. 



1917a. Photograph of the Sun, by Mr. Rutherfurd, taken 

 with his triple combination. J. Norman Lockycr, F.R.S. 



1917b. Enlarged Photographs of the Sun, taken by M. 

 Janssen. J. Norman Lockyer, F.R.S. 



