The unequal expansion of paper is a subject of interest, not only in connection with gelatine paper for development, but with various photographic processes. In making carbon transparencies for instance, the gelatine film which is squeegeed against the glass necessarily takes its dimensions from the paper to which it is attached, and if that be expanded more in the one direction than another, the transparency is similarly deformed; and so, of course, is any negative, enlarged or otherwise, produced in the camera therefrom. A reproduced negative by contact printing may either have the distortion due to expansion of the paper bearing the gelatine film removed or doubled, according to the direction in which the paper is used for the new negative.--_W.E. Debenham, in Br. Jour. of Photography_. * * * * * MEASURING THE THICKNESS OF BOILER PLATES. An ingenious process for determining the thickness of iron plates in boilers, or places where they cannot otherwise be measured without cutting them, has been invented by M. Lebasteur. He spreads upon the plate the thickness of which he desires to find, and also upon a piece of sheet iron of known thickness, a layer of tallow about 0.01 inch thick. He then applies to each, for the same length of time, a small object, such as a surgeon's cauterizing instrument, heated as nearly as possible to a constant temperature. The tallow melts, and as in the thicker plate the heat of the cautery is conducted away more rapidly, while in the thin plate the heat is less freely conducted away, and the tallow is consequently melted over a large area, the diameters of the circles of bare metal around the heated point, bounded after cooling by a little ridge of tallow, will be to each other inversely as the thickness of the plates. The process is stated to have given in the inventor's hands, results of great accuracy. * * * * * GROUPS OF STATUARY FOR THE PEDIMENT OF THE HOUSE OF PARLIAMENT IN VIENNA. The pediment of the central pavilion and the two side pavilions of the new House of Parliament, at Vienna, are to be ornamented with groups of statuary. The group in the middle pediment represents the granting of the constitution by the Emperor Francis Joseph, and was executed by Professor Helmer. [Illustration: STATUARY FOR THE VIENNA HOUSE OF PARLIAMENT.--SCIENCE AND LITERATURE. (GROUP TO THE LEFT.)] The pediment of the left wing is ornamented by a group representing Justice, and the pediment of the right wing by a group representing the Home Government. Johannes Benk, the well known Austrian sculptor, designed and executed the last mentioned group. The two figures at the left hand end of this group represent Science and Literature, and those at the right hand end, Industry and Commerce. The entire group consists of nine figures, the middle figure being seated and the rest standing, sitting, and lying, as the space in the pediment allows.