The researches of Daguerre and Nicéphore de Niepce had established, before Queen Victoria ascended the throne, the possibility of obtaining permanent images by the action of light on silver-plated copper, but the first notable advance in the new art of photography was the invention of the calotype by Fox Talbot, who applied iodide of silver to paper, which was rendered sensitive to light by further treatment. Then, in 1850, came the collodion process, and the subsequent discovery of dry-plate processes brought photography within easy compass of amateurs, and greatly enhanced the value of photography as an aid to science. The exposure of thirty minutes, required under the Daguerrotype process, has been reduced to one-fifteenth of a second by the use of gelatine emulsion. The latest manifestation of photographic skill is certainly very marvellous, namely, the kinematograph. By a rapid succession of instantaneous exposures a series of plates is obtained so closely consecutive that when the images are reflected in equally rapid succession upon a screen, men and animals may be seen the size of life in natural movement. [Illustration: THE BUILDING OF A WARSHIP. Finishing the upper works of H.M.S. _Jupiter_ at Clydebank. In the dock are also five torpedo-boat destroyers.] [Sidenote: Its Effect on Painting and Engraving.] Photography has had a powerful effect on the art of painting, not only by the cheap reproduction of acknowledged masterpieces, which is not without risk of encouraging conventionalism in design, but by creating a more exacting standard of fidelity to nature. While it has caused some painters to seek after intense realism, it has led others to a reactionary course which they term impressionism. Judging roughly from the vast numbers of pictures painted and exhibited each year, and from the immense prices given for the works of favourite masters, both living and dead, it is difficult to believe that, however great may be the aggregate expenditure by the purchasing public on photographs, it has interfered appreciably with the sale of pictures. One branch of art certainly has suffered by the rivalry of sun pictures, namely, the various kinds of engraving. Wood-engraving, indeed, had already run to seed during the present century, from the affectation of craftsmen to a freedom and rapidity of which the material was not really capable: but engraving on copper and steel, etching, lithography, and, above all, mezzotint engraving (said to have been the joint invention of Prince Rupert and one of his officers named Siegen), had lost none of their delicacy and power when photography invaded their province. Excellent results are obtained from the best methods of photogravure and photolithography, and, where absolute accuracy of detail is required, they leave little to be desired; but the extent to which cheap "process" plates have supplanted the older arts of book illustration affords much to deplore from an artistic standpoint.