Rensselaer Union, Volume 7, Number 52, Rensselaer, Jasper County, 16 September 1875 — MECHANICAL AND SCIENTIFIC. [ARTICLE]

MECHANICAL AND SCIENTIFIC.

i —Trichin* have lately' been found for the txr.it time in the flesh of a wild boar Rilled in the Harz Mountains, (Germany. Hitherto this parasite has been supposed to be coiiflned to the domesticated animal. —ln calculating the strength of iron columns the safe plan is to find the diameter of a solid column necessary to bear the compression,, and then distribute the same area of metal in tube form or a hob tow column. —Having observed that the discharge from a power fill electrical machine produced remarkable changes in the color of plants, M. Becquerel ascribes this result to the rupturing of the cells containing, the coloring matter. This opinion is sustained by the fact that when the cellular envelope* Is washed the leaf becomes white —for the protection of iron and steel tools against rust Vogel recommends a solution'of white wax in benzine. The latter, heated, will dissolve half its weight of wax." This will preserve the metal, even from the action of acid vapors. Apply with a brush. —ln order to remove all doubt as to the accuracy of the results of preceding investigators Dr. Herwig has sought to determine the velocity of transmission of magnetic influences by separating die various portions of his* apparatus to very considerable distances, and he concludes that if the action of the terrestrial magnetism really possesses a definite velocity it must amount to at least a half million miles per second; or, in other words, that the terrestrial magnetic influence makes itself felt at any point of the earth’s surface in less thap 1:300 of a second. —Oadogan Morgan, in 1785, was the first experimenter who produced the electrical light in the interior of solid bodies. He inserted two wires in wood and caused the spark to pass between them. The wood was illuminated with blood-red or with yellow light, according as the depth at which the spark was produced was greater or less. Many of our readers have doubtless seen an egg or a series of eggs lighted up by being placed in the line of discharge of a 1-eyden jar. An ivory ball, an orange or an apple may be illuminated in a similar way. According to Tyndall a lemon is especially suited to this experiment, “ flashing forth at every spark as a spheroid of brilliant golden light." The wires used for the discharge should be brought within about half an inch ot each other inside the lemon. —Pictures maybe transferred to painted surfaces in the following manner: Cover the ground with an even coat of light-cbl-ored carriage varnish, which should he allowed to set (nearly as dry as if for gilding). If the print to be transferred be col-, ored soak it in salt and water; if not colored use water alone. Remove superfluous water by pressing between blotting pads, and tlieu place the picture face down upon the varnish, pressing it srpooth. When the varnish is dry dampen the paper ami rub it oil with the finger. The picture will be found upon the varnish, and another coal of the latter should be added to Unng ou! the effect. This process answers equally well for glass or metal surfaces. — Scientific American. % ■ —A new arrangement for preventing the dangerous irregularities which occur in steam cylinders has been devised by M. Waeyeubcrdi, in which the plan is adopted ot piecing tw o or more escapes and sets of slides\>n different sides of the cylinder, and in such a manner that they are all connected with the extremity of the cylinder by the same passage. The steam is admitted and its introduction governed directly by the regulator, according to the work to be done. With this object the arbor of the levers which command the valve slides forms part of a sliding sector, which is furnished with moving work, rendering it at any determined moment independent of the slides and transmission rods. When this occurs the steam-way. which was open, closes instantaneously, and, the inlet being suppressed, the steam acts by means oi expansion in the cylinder until the piston has reached the end of its stroke; on the latter taking place the discharge port opens and the steam passes into another cylinder, into the condenser, oj- into the air. according to the circumstances of the c'ase.