Science Siftings

New Zealand Tablet, 19 September 1912, Page 59

Science Siftings

By ‘ Volt.’

The Cost of Great Canals. The cost of the Panama Canal — 40 miles, including losses on M. de Lesseps’ scheme (£80,000,000), will be £160,000,000; that of the Suez Canal 100 miles — 1 was £20,000,000; that of the Manchester Ship Canal--351 miles was £15,000,000, and that of the Kiel Canal —6l miles was £8,000,000. Rope Horseshoes. Rope horseshoes are largely used in Germany and some other European countries. The rope portion is inserted in a metallic body or frame, and in most instances provision is made for withdrawing a worn rope section and replacing it with a new one. In some instances the rope, which is sometimes tarred, has wire of other reinforcing material interwoven with it. Berlin is the headquarters of a syndicate composed of eight manufacturers located at different points of Germany. Electric Light Service in Denmark. According to recent information about the progress of electric light and power industries in Denmark, it appears that all the towns of 5000 inhabitants and over are now provided with public electric service. As to towns lying between 5000 and 3000 inhabitants, there are only three in which electric mains are not installed, so that it will be seen that Denmark is one of the most progressive countries in this respect. The largest sized electric stations are to be found at Copenhagen, and at present there are three large plants in operation, giving a total of 27,000 horse-power. Current is supplied for the city mains as well as for the tramway lines, As regards the Danish stations in small towns, in general each town has its own plant, and there is but one example of an intercommunal system. This is at Skovshoved, near Copenhagen, and the central station extends its power lines over all the suburban region also supplying the tramways of Hellerup and Klampenburg. In most of the towns electric stations the Diesel heavy oil engine is used. Inventor of Photography. The science of photography, which has in recent years been brought to such a high degree of perfection, was first introduced by the French inventor, Louis Jacques Maude Daguerre, of Cormeilles, Prance, in 1839. Daguerre began life as a scene painter, and soon surpassed his competitors by his originality of design and effectiveness of execution. He travelled extensively in Europe and worked on many of the famous panoramas in Rome, Naples, London, and other cities, and conceived the idea of giving effectiveness to the views by showing colored lights and shadows on them, so as to produce the various changes of the day and season. He had a partner, Niepce, with whom he studied and experimented for years to perfect a plan for producing facsimile copies of objects from the chemical action of the sun. Niepce died in 1833, and Daguerre continued his studies alone, and made such improvements in the process that the son of Niepce cheerfully consented that the invention should be known by the name of Daguerre alone, instead of both, as had been agreed upon. The invention was announced at the session of the Academy of Sciences in January, 1839, and the practical tests excited a profound interest. The same year Daguerre offered to the French Government to make the invention public for the small annuity of £l6O to Niepce’s son and a similar one to himself. The offer was accepted, and Daguerre’s annuity was made £240 upon his agreeing to make public all further information he should possess in regard to improvements. He was made an officer of the Legion of Honor, in recognition of the generous and noble spirit which prompted him to place his valuable invention at the disposal of the public, instead of keeping it as a private monopoly for personal gain. He died on July 12, 1851, at the age of sixty-two years.