2 carte-de-visite photographs of solar PROMINENCES, Observatory of Dartmouth College, Hanover, NH, September 28, 1870, oval albumen prints mounted, each 2½ x 3¾ inches (65 x 97 mm), together with cabinet photograph of spectroscope that was made by Alvan Clark & Sons in 1869 for Dartmouth College, albumen print mounted, 4 x 6¾ inches (105 x 170 mm), captioned below in ink, all printed by H.O. Bly of Hanover, NH.

THE EARLIEST PHOTOGRAPHS OF SOLAR PROMINENCES. On September 28, 1870, Young announced that "this afteroon, with the help of Mr H.O. Bly, our photographer ... I have succeeded in obtaining photographs of protuberances on the sun's limb, of which I enclose a specimen. They were obtained by attaching a small camera to the eye-piece of the telescope and opening the slit somewhat widely" (Journal of the Franklin Institute, third series, vol LX pp 232a-233b).
The two cartes-de-visite have printed captions on verso reading, "Protuberances or Clouds of Incandescent Hydrogen on the edge of the sun's disc. Photographed by the aid of a Spectroscope at the Observatory of Dartmouth College, September 28, 1870." The cabinet photograph is illustrated in Warner and Arial p 36.