Popular Science Monthly/Volume 23/July 1883/Machines Driven by Solar Rays
By GASTON TISSANDIER.
OUR readers have already been informed respecting the solar machines constructed by MM. Mouchot and Abel Pifre, in which the heat of the sun is employed, either directly or through the agency of steam generated directly by it, as the source of power, and of their successful application to certain purposes in Algeria. M. Pifre, who is an assistant to M. Mouchot in his engineering work in Algeria, has continued his experiments, and made some improvements in the machines, by which their operation has been rendered more effective. The principal improvement is in the form of the reflector, or insolator, by means of which the rays of the sun are concentrated upon the boiler or other object to be heated. M. Mouchot's reflector was in the form of a simple hollow cone, formed with a straight line of projection. M. Pifre bends the line of projection so as to give it three different inclinations, and thereby obtains for the surface of his mirror a form nearly like that of a paraboloid. An interesting experiment upon the possibility of adapting the apparatus of M. Pifre to a European sun was made on the 6th of August last, in the Garden of the Tuileries, Paris, on the occasion of the festival of the Union Française de la jeunnesse. An insolator, the reflector of which had an extreme diameter of three and a half metres, or nearly twelve feet, was set up near the steps of the Jeu de Paume. The steam generated in the boiler, which was placed in the focus of the mirror, was applied to a small
Printing a Newspaper by Solar Heat.
Experiment by M. Abel Pifre in the Garden of the Tuileries, Paris, August 6, 1882.
vertical engine of thirty kilogrammetres power, and this was connected with a Maroni press. Although the sun was not very hot, and the radiation was interrupted by frequent clouds, the press was kept in regular operation from one o'clock in the afternoon till half-past five, printing on an average five hundred copies an hour of a journal specially prepared for the occasion, and called "Soleil-Journal" (Sun-Journal). This little experiment is not likely just yet to produce a revolution in the art of printing, but its success may enable us to judge, in some degree, how useful the insolators may be made in latitudes where the solar radiation is more intense and more constant than in Paris. The engraving correctly represents the arrangement of the apparatus. M. Pifre's insolator is shown in the center, with its great parabolic mirror. The engine which it drove is shown by the side of it, while on the right and in the foreground may be seen the press printing the journal. We have a right to believe that heliodynamics may at some future time be usefully and profitably employed in hot countries.