*Edmond BECQUEREL (1820-1891) physicist. L.A.S., La Jacqueminière près Courtenay (Loiret), 14 August 1863, to a "dear colleague
and friend"; 4 pages in-8 to his number.
A long and interesting letter on his work on electric light, alternating and direct current, etc. He had to stay in the country until November and therefore could not give "all the indications you desire concerning the use of electric light. The electric light in question is that which is obtained with magneto-electric machines, built in Paris and which are only Clarke's great machines; but, and this is an interesting innovation, the induced currents are used alternately in opposite directions, so that there is no need for a switch. The electric light obtained, when the machines are powerful enough, is much cheaper than that of gas, but provided that the powerful focal point formed by the voltaic arc is used and not divided; it is therefore not in ordinary public lighting that it may be used, but in special cases such as for lighthouses, signals on board steamers, lighting of passes near the coast, mines, etc., and in the case of lighthouses, for example. He indicates several publications in which he has recorded the results he has obtained, as well as the editions of his reports and works, particularly on the light of electro-magnetic devices. If these works are not to be found in Turin, a request may be made to Prince Napoleon, President of the Imperial Commission. He can also refer to last year's exhibition in London, and he will also find documents in "nos annales du Conservatoire des Arts et Métiers", etc... His father [the famous physicist Antoine Becquerel] is sensitive to his good memory and recalls his excellent friendship: "he has all the activity possible and is preparing to reprint his treatise on electro-chemistry"...
Location of the item France - 75016 Paris