The invention of the magic lantern dates back to 1650, and is attributed to Professor Kircher, a German philosopher of rare talents and extensive reputation. The instrument is simple and familiar. It is a form of the microscope. The shadows cast by the object are, by means of lenses, focussed upon something capable of reflection, such as a wall or screen. No essential changes in the principles of construction have been made since the time of Kircher; but the modern improvements in lenses, lights, and pictures, have raised the character of the instrument from that of a mere toy to an apparatus of the highest utility. By its employment the most wonderful forms of creation, invisible, perhaps, to the eye, are not only revealed but reproduced in gigantic proportions, with all the marvelous truth of nature itself. The success of some of the most celebrated demonstrations of Faraday, Tyndall, Doremus, Morton, and others, was due to the skillful use of the magic lantern. As an educator, the employment of this instrument is rapidly extending. No school apparatus is complete without it; and now that transparencies are so readily multiplied by photography upon glass, and upon mica, or gelatin, by the printing press or the pen, it is destined to find a place in every household; for in it are combined the attractive qualities of beauty, amusement, and instruction.
The electric light affords, probably, the strongest and best illumination for the magic lantern; then comes the magnesium light; but their use is a little troublesome and rather expensive; next to these in illuminating power is the oxy-hydrogen or Drummond light. The preparation of the gases and the use of the calcium points involve considerable skill.
Need has long been felt for some form of the magic lantern, having a strong light, but more easily produced than any of those just mentioned; and this has at last been accomplished, after several years' study and experiment, by Prof. L.J. Marcy, 632 Arch St., Philadelphia, Pa.
The "Sciopticon," is the name of his new instrument, and from actual trial we find that it possesses many superior qualities. Its lenses are excellent, and in illuminating power its light ranks next to the oxy-hydrogen. The sciopticon light is produced from ordinary coal oil by an ingenious arrangement of double flames, intensifying the heat and resulting in a pencil of strong white light. Prof. Marcy's instrument is the perfection of convenience, simplicity, and safety. Any one may successfully work it and produce the most brilliant pictures upon the screen. It is peculiarly adapted for school purposes and home entertainment. Those who wish to do a good thing for young people should provide one of these instruments. Photographic transparencies of remarkable places, persons, and objects, may now be purchased at small cost; while there is no end to the variety of pictures which may be drawn by hand at home upon mica, glass or gelatin, and then reproduced upon the screen by the sciopticon.
The Largest Well in the World--Capacity 1,000,000 Gallons of Water per Day.
One of the grand necessities of the Prospect Park, Brooklyn, N.Y., that of providing for a continual supply of water for all the purposes of the Park developed itself, as the Commissioners progressed with their stupendous undertaking. Mr. Stranahan, the President of the Board, after carefully weighing the cost, the practicability, and importance of having an independent water supply for the Park, advised the Commissioners of the plan which had suggested itself, and the calculations which had been made by the engineers relative to the project, and the work was commenced, the first idea being to secure at least a partial supply of water by means of a well constructed in the Park. The subject was thus treated in the last annual report of Mr. C.C. Martin, the engineer in charge:
"This well has been located on the south side of Lookout Hill, near the lake, and work was commenced upon it late in the season. After a careful consideration of various methods for sinking the well, it was decided to build the wall and then to excavate the material from within, trusting to the weight of the wall to force it down. Sixteen feet of the wall were laid securely bolted together, before the excavation was commenced. A derrick with a boom fifty-five feet in length was set up near the wall, so that the sweep of the boom commanded the interior of it. Iron buckets containing fourteen cubic feet each were obtained, and a six-horse power hoisting engine purchased. With these appliances the excavation was commenced, and carried on with slight interruption until the work was suspended on account of the frost."
The well is now completed, and is one of the most important features of the Park. It is worthy to rank as a feat of engineering skill with, any of the great works of modern times. The Commissioners decided to put its powers to the test yesterday afternoon, but owing to the unpropitious weather of the forenoon the trial was postponed. Nevertheless, Commissioners Stranahan, Fiske, and Haynes, with Mr. Martin, engineer in charge, and Mr. John Y. Culyer, his assistant, were at the well. During the last summer some difficulties were encountered in the sinking of the wall, which were set down by superficial observers as the utter failure of the enterprise. Mr. Stranahan received but little encouragement from his fellow Commissioners, some of whom had never seen greater works of engineering than the construction of street sewers. He assumed the responsibility of seeing the work through, feeling that the whole thing depended entirely upon the ability of the engineers, in which he had abundant faith. All obstacles were surmounted; the work proceeded and the well is now finished, and so far as is known, is understood to be the largest one in the world.