London, Harrison & Sons, 1909 Large4to. Original printed wrappers. Offprint from: "Philosophical Transactions of the Royal Society of London, Series A, Vol. 209. pp. 281-317." With cloth backstrip and I small nick to upper and lower corner of front wrapper. A fine and clean copy. Pp. 281-317.
Scarce first edition, off-print issue, of Bohr's first published paper, constituting his only ever work in experimental physics.
"His first research project, a precision measurement of the surface tension of water by the observation of a regularly vibrating jet, was completed in 1906, when he was still a student, and it won him the gold medal from the Academy of Sciences. It is a mature piece of work, remarkable for the care and thoroughness with which both the experimental and theoretical parts of the problem were handled." (DSB).
This Bohr's fist paper grew out of a work which Bohr did in 1906, and for which he won a gold medal from the Academy of Sciences. The subject was to experimentally investigate a method, proposed by Lord Rayleigh, for measuring the surface tension of water by the observation of a regularly vibrating jet. "Bohr [...] included in his work essential improvements on Rayleigh's theory by taking into account the influence of the liquid's viscosity and of the ambient air, and by extending the earlier theory from infinitesimal to arbitrary large vibration amplitudes. In order to execute his experiments he had first of all to cope with one complication. The university had no physics laboratory." (Pais, p. 101). Bohr thus constructed many of the instruments himself using his father's laboratory. ""I did the experiments completely alone alone in the physiological laboratory... it was a great amount of work", which was technically demanding." (Pais, p. 102).
In spite of being Bohr's only ever work in experimental physics, it documents his deep understanding of the methods of experimentalists.
"On 23 February 1907 the Academy notified him that he had won its gold medal. In 1908 he submitted a modified version to the Royal Society in London. It was his first and last paper on experiments he himself performed. His second publication was his last to deal with surface tension of liquids; it was purely theoretical. Both papers were favorably referred to in later literature.
The manuscript of the prize essay, never published in its original form, is preserved in the Bohr Archives. It is handwritten, by Harald Bohr [i.e. his brother]." (Pais, p. 102),
Rosenfeld, Bohr Bibliography No. 1. Rosenfeld, Dictionary of Scientific Biography II, pp. 239. Pais, Niels Bohr's Times, pp. 101-02.
Order-nr.: 54014