In 1862 and 1863 it was frequently employed in Spain during the night in the construction of railways. During the late Franco-German war in 1870 it was applied to submarine illumination, and more lately it has been used in a series of street illumination in St Petersburg.
The electric light apparatus was placed on the tower of the Admiralty Buildings of that city, and by means of it three of the larger streets were illuminated at night from 7 until 10 o’clock. In this latter case, as well as in that of the Rouen Docks, the lamps were supplied with the electric current generated in batteries.
It may be said, however, to have been only within the last two years that the question of electric lighting has developed into a burning one, and that the light itself has become so much more generally and extensively adopted.
This new era in the history of artificial illumination may be said to date from the introduction of two forms of dynamic magneto-electric apparatus, the one invented by Dr Siemens, the eminent telegraphic engineer, the other by M. Gramme, of Paris, who, from having been formerly a journeyman carpenter, has now become the head of a manufacture which forms a most important branch of scientific industry.
In the apparatus of Gramme and Siemens three marked features and improvements over the older machines have been achieved:—
1. A great reduction in size, and, consequently, in cost, and requisite space for the machine.
2. The method of generating large quantities of electricity by the mutual action between the different parts of the same machine, and the induction therein set up.[14]
[14] This discovery was made independently and nearly simultaneously by Drs Siemens and Sir Charles Wheatstone.
3. The production of the electric current at a much less expenditure of motive power.
On this latter point Professor Tyndall, in his report to the elder brethren of the Trinity House, states that magneto-electric machines of old construction cost ten times more, occupied twenty-five times the space, and weighed fourteen times as much as the recent machines, while they produced only one-fifth of the light with practically the same driving power; which in effect amounts to this—that taking illuminating effect in each case into consideration, the new machines cost one-fiftieth, and are, as regards space occupied, 125 times more advantageous than the earlier forms.