Democratic Sentinel, Volume 17, Number 38, Rensselaer, Jasper County, 6 October 1893 — POPULAR SCIENCE NOTES. [ARTICLE]

POPULAR SCIENCE NOTES.

To Take the Place of Leather.—* A new material is proposed as a substitute for leather. It is called “flexus fibra,” and is derived from fl%x, suitably prepared and oiled. It has the same appearance as leather, is particularly supple, and takes a polish eqaliy well with the best kinds of calf. The material is said to possess great tenacity, while affording great ease and comfort to the foot when made into shoes, Flexus fibra. being of vegetable origin, is calculated also to facilitate free ventilation, and thereby to obviate the discomfort arising from what is called “drawing”the feet.

The Inter-Relation or Foaoss.— Water freezes and becomes ice at 32 degrees of Fahrenheit, whereas mercury freezes at 39 degrees below zero of Fahrenheit; olive oil, on the contrary,shows signs of oongelation at from 40 to 45 degrees of Fahrenheit. The three substances quoted being all liquids the difference in the lose of heat requisite to bring them to solidification is very great indeed. The action of heat on fluids or solids is equally various. Water boils at 212 degrees Fahrenheit, lead melts at 612 degrees; the fusing point of gold is 2,016 degrees, and of iron 8,000 degrees. Wo five these particulars in order to show . hat enormous changes can be effected by cold in the transmutation of a substance from a liquid to a solid, or by beat from a solid to a liquid state. Ether boils at 96 degrees Fahreuheit, but has never been frozen by the severest cold. The forces exerted by the action and reaction of heat and cold are best exemplified under the head of steam, which has only been called forth and made use of by man since about the middle of the eighteenth contury, but it has been in action on a gigantic scale in nature for probably hundreds of thousands of years, it being the opinion of many geologists, including Lyell, that it ie the generation of steam, whether developed by the internal heat of the earth in a state of fusion, or whether by that of the chemical action of the elements in the bowels of the earth developing heat, which, acting on water and thus generating steam, is the great force that throws up such enormous rocks and masse* of lava as Etna has been doing. The rocks and lava thus thrown up areiu a state of fusion by heat; but they gradually cool by exposure to the air and form solid rocks and mountains. This action and reaction has been ?oing on for thousands of years with little cessation. Heat and cold, again, cause the oceanic currents on our earth between the equator and the poles, and vice versa, and thereby affect the earth’s magnetism or polarity, not only on our globe, but probably all throughout the universe. This is borne out by the fact that “the aurora borealis is decidedly an electrical phenomenon, which takes place in the highest regions of the atmosphere, since it is visible at the same time at places very distant from each other. Dr. Faraday conjectures that the electric equilibrium of the earth is restored by aurora oonveying the electricity from the poles to the equator.”—[Westminster Review.

Thr Ordinary Thermometer.—Ordinary thermometers are generally defective, says a scientific writer, because of slovenly work in making them; ihe testing, pointing and sealing being carelessly done. Tests should only be made by comparison with a standard thermometer, placed with the instrument to be tested under water. But in the cheap shop the water used is often allowed to grow cool, and is then suddenly warmed by an addition of hot water. The testing accordingly is inaccurate. In these shops also the zero point is determined simply by placing the bulb in snow, and when the mercury has become stationary the thumb is placed on the point where this is shown and a file makes the mark. The initial point is usually thus misplaced from a sixteenth to an eighth of an inch, and the whole scale is rendered wrong. Thermometers with metallic plates arc sometimes incorrect. The degrees on them are marked by means of dies, which cause a warping or curling of the plates. These have to be rolled to flatten them again, and this causes an increase in the size both of the plates and the degrees. Allowance is sometimes made for this in making the dies, but the result is usually unsatisfactory. A further source of error in this kind of thermometer comes from the fact that most of them are tested at one point. The manufacturer relies on a scale of degrees that is very nearly true, aud uses it for all instruments haring a bulb of like size. The result is that the thermometers are in error at certain points. It is for this reason also that glass thermometers, which have degrees marked upon the glass with type, are apt to be incorrect. The type used is the same for all glass of a similar kind, notwithstanding thi t the bulbjs may vary in size. Sc’entific thermometers are usually tested as to their accuracy before they are used at some authoritative observatory. In England this is done at the government station at Kew; in this country at the physical laboratory at Yale and Harvard Universities, and at the Smithsonian Institution. Certificates are granted showing the amount of error, if any.