The Journal of the Royal Astronomical Society of Canada November-December 1909: Vol 3 Iss 6
An issue of the Royal Astronomical Society of Canada's bimonthly journal, published in Toronto in 1909 for members and working astronomers, reproduced here from microfilm. The plate shows stacked spectrograms — horizontal bands of dense vertical absorption lines, each labelled with an exposure time and set against grainy grey film stock; usable as ready-made line patterns, barcode-like rules, and halftone texture.
