THE DOUBLE-SLIDE PLATE-HOLDER ON YERKES 40-INCH REFRACTING
TELESCOPE 49
Photo: H. J. Shepstone.
MODERN DIRECT-READING SPECTROSCOPE 49
By A. Hilger, Ltd.
CHARLES DARWIN 56
Photo: Rischgitz Collection.
LORD KELVIN 56
Photo: Rischgitz Collection.
A GIANT SPIRAL NEBULA 57
Photo: Lick Observatory.
METEORITE WHICH FELL NEAR SCARBOROUGH AND IS NOW TO BE SEEN
IN THE NATURAL HISTORY MUSEUM 57
Photo: Natural History Museum.
A LIMESTONE CANYON 60
Reproduced from the Smithsonian Report, 1915.