FOOTNOTES:
[1] According to the usual terminology of those times, an »electro-magnetic« machine means a machine driven by electricity, an electromotor, while, on the other hand, a »magneto electric battery«, or a »dry battery« is a machine for producing electricity.
[2] Specification of Patent No. 12295, 1848.
[3] After the publication of my first treatise in the »Elektroteknikeren«, for February 1907, various parties have objected that Hjorth, in his dynamos, did not use the dynamo principle in its purest form, as he had one large, unwound, cast iron magnet. On the contrary, the above-mentioned leaf of his sketch-book shows that Hjorth, as early as in 1851, has used the dynamo principle in its purest from—exactly the same as used by Siemens in 1867—as all the field magnets have been wound cast iron magnets, and the initial current is induced by the remnant magnetism of these magnets. S. S.
[4] This is correct, as long as he uses armatures with but a single winding, because, in that case, the number of armature windings is proportional to the number of steel magnets. Whereas Hjorth is mistaken, when in 1867 he makes the same statement about a machine, where nothing prevents the armature from being fitted with a great number of windings.
[5] Specification of Patent No. 2198, 1854.
[6] Specification of Patent No. 806, 1855.
[7] Specification of Patent No. 2199, 1854.
[8] Specifications of Patents No. 807 and 808, 1855.
[9] Hjorth’s English passport, from 1855, contains this information: Height: 5 feet 7 inches, Complexion: fresh, Eyes and Hair: grey.