[1] From an early age, the younger Rowland exhibited marked scientific tastes and spent his spare time in electrical and chemical experiments.

He was unable to secure the publication of many of his early scientific papers; but James Clerk Maxwell at once saw their excellence, and had them printed in Philosophical Magazine.

When the managers of Johns Hopkins University in Baltimore, Maryland, asked advice in Europe as to whom they should make their professor of physics, Rowland was overwhelmingly recommended as the best choice.

[2] In the interval between his selection to Johns Hopkins and the assumption of his duties there, he studied physics under Hermann von Helmholtz in Berlin (1875–76),[3][4][5] and carried out a well-known research on the effect of an electrically charged body in motion, showing it to give rise to a magnetic field.

[8] For this he obtained a value which was substantially different from that ascertained by the committee of the British Association appointed for the purpose, but ultimately he had the satisfaction of seeing his own result accepted as the more correct of the two.

In 1882, before the Physical Society of London, Rowland gave a description of the diffraction gratings,[11][12] with which his name is specially associated,[a] and which have been of enormous advantage to astronomical spectroscopy.

These gratings consist of pieces of metal or glass ruled by means of a diamond point with a very large number of parallel lines, on the extreme accuracy of which their efficiency depends.