1869.] The Sutherland Steam Pump. 533 Lehigh, and different parts of our own and other States, have adopted and recommend it, as unqualifiedly as Mr. Follensbee. We have mentioned the stillness with which the one at " Ripka Mills" does its work. A gentleman the other clay, in our hearing, spoke of the annoyance suffered, in one of our finest hospitals, from the rattling of the steam-pump, used to force water to the different wards and apartments, and we thought that, perhaps, the most agreeable of the advantages attained by the Sutherland Steam-Pump, is its quietness ; for it can be used, in public institutions, or private dwellings, without disturbing any of the inmates. So far, we have spoken only of the Engine, because the chief specialty is found in its construction ; but the Pump part, also, is characterized by an inge- nious and efficient arrangement. It is double-acting; and has two hinge-valves, communicating with the suction-pipe ; and two similar valves, communicating with the delivery-pipe. These valves are hung singly, or in pairs, or all to- gether, in a plug, or cylinder, which is inserted in an opening, made for the purpose, and fastened there. Thus the valve may readily be removed and ex- amined. The accompanying perspective view, while it shows the compactness of the machine, will not enable an}', but an experienced e} T e, to trace the internal construction, from the description we have given ; and we regret, that we can- not give a vertical section, by means of which an}- person could follow the course of the steam through its ports and pass- ages, so admirably and yet so simply adjusted, one can hardly help thinking, that the expansive creature, as it rushes along, must rejoice at the ingenuity, which allows it to do so much work, with such celerity and certainty. This Pump is already in extensive use; and the manufacturers warrant all sizes. It was patented, in the United States, August 14th, 1866. Re-issued March 26th, 1861, and February 18th, 1868. Patented in England, October 8th, 1868.' The agents are Messrs. Gregory & Stewart, No. 447 North Broad Street, Philadelphia. Glass Mosaics. — The production of glass mosaics requires unwearied pa- tience, combined with much skill and taste. In the first place, the materials of glass are mixed with various coloring substances, chiefly metallic oxides, so as to form opaque colored enamels ; these enamels are cast into slabs, or flat cakes; and the slabs are cut into very small cubes, or rectangular pieces. Not only is every color imitated, but every grada- tion of tint in each color ; insomuch, that, at the great mosaic establishment at Rome, maintained by the Papal gov- ernment, they have no less than thirty thousand different tints of colored enamels, all classified and registered. With these little colored cubes, a picture is built up, cop3'ing some celebrated work of the Italian or other masters. The pieces are inserted, one by one, in a bed of cement, which dries to extreme hardness. Each piece is ground, at a kind of lathe, to the exact shape re- quired by the particular tint in each part of the picture ; and when the pic- ture is completed, by this extremely slow process, the surface is ground down and polished. Views of St. Peter's, the Colosseum at Rome, the Roman Forum, the Temple of Passtum, the Harbor of Genoa, the Bay of Na- ples, &c, were in the Italian compart- ment of the Great Exhibition. The minutest touches, the most delicate tints, were imitated, and in some in- stances with surprising f ucc^ss^ It must be remembered, too, that these colors are not mere surface tints, not merely "skin deep." They permeate the sub- stance of the glass, each little fragment having the same tint all through its thickness.
