A German handbook on the patterns of light that atoms and molecules give off, 1910

Spectroscopy studies the light that atoms and molecules give off or absorb, and before there were electronic spectrometers to take the measurements, physicists and chemists relied on printed reference works to look them up. Heinrich Kayser’s Handbuch der Spectroscopie was one of the large ones, issued in several volumes; this is the fifth, published in Leipzig by S. Hirzel in 1910.

It is a book to consult rather than to read through. The pages sampled are dominated by tables of numbers, the observations and measured data of atomic and molecular spectra, and the title page lists two plates and three figures. Matching copies are recorded at about 853 pages. For a historian of science, it shows how much had been measured, and how it was organised, at the start of the twentieth century.

This is the fifth volume on its own, issued separately, not a set. It is in its original pinkish paper wrappers, chipped and torn at the corners, with a rubbed and fragile spine, and its completeness has not been fully checked.