The brothers, Nicephore and Claude Niepce, made a boat run on the Saone in i8o6 by the combustion of lycopodium powder. On December ISth of that year Lazare Carnot, the famous " organizer of victory," and Berthollet rendered a report upon the machine to the Academy in Paris. In spite of the discarded term, caloric, we can readily understand their formal judgment. " In the apparatus of Messrs. Niepce no part of the caloric is dissipated in advance. The active force is an instantaneous product and the entire effect of the combustible is used to cause the expansion which serves as the active force." The two reporters cite experiments witnessed by themselves in which a simplified machine worked with lycopodium powder or with powdered coal mixed with resin.
The French Technical Aeronautics Service entrusted to M. Clerget the reconstruction of the Niepce machine, for which the patent was granted July 2o, ISo8. The drawings are so clear and comprehensive that it was possible to reproduce the motor with little difficulty. The machine worked well. With 5 cg. of lycopodium a weight of 20 kg. was lifted 3 ยฐ cm. This gives an efficiency of 4 per cent. with the machine cold. For the wick used in the original machine to explode the mixture a wire heated by the current was substituted. The author holds that to the Niepce Brothers must be conceded the following, the use of powdered combustibles fed mechanically by a rotary distributor and the injection of the fuel into the combustion chamber with the aid of compressed air. In these two points he holds that the Diesel patents of I892 and I894 were anticipated.
The Niepce Brothers tried also to employ petroleum but failed. For Nicephore Niepce is claimed the distinction of inventing photography and a statue in his honor adorns Chalons sur Saone, where he was born in I765. In the nmseum of that town the reviewer was disappointed, by failing to find any exhibit of his photographic work.
G. F.