Mr. Glaisher has found that “the amount of ozone at stations of low elevation is small; at stations of high elevation, it is almost always present; and at other and intermediate st...
Since the increased attention paid to the signs of forthcoming weather of late years, and the good which has resulted therefrom to farmers, gardeners, civil engineers, miners, fish...
Professor W. Thomson, of Glasgow, has devised an atmospheric electrometer, which is likely to become eminently successful, in the hands of skilful observers. It is mainly a torsion...
Fig. 1. The first instrument which gave the exact measure of the pressure of the atmosphere was invented by Torricelli, in 1643. It is constructed as follows:—A glass tube, CD (f...
A RISING BAROMETER. A “Rapid” rise indicates unsettled weather. A “Gradual” rise indicates settled weather. A “Rise,” with dry air, and cold increasing in summer, indicates wind fr...
The two fixed points having been determined, it is necessary to apply the scale. The thermometers in general use in the United Kingdom, the British Colonies, and North America are...
Fig. 31. Very recently quite a novel design has been patented by Mr. Howson, for a long range barometer. The construction requires neither distortion of the tube, nor mechanism for...
Alcohol does not expand equally for equal increments of heat, consequently errors are likely to exist in the scale indications unless the graduations are very accurately—not nece...
The directions for fixing the barometer, and making it portable when it has to be removed, should be attended to carefully. The barometer should be suspended against a frame or pie...
“As the interchange of heat between two bodies by radiation depends upon the relative temperature which they respectively possess, the earth, by the rays transmitted from the sun d...
The normal boiling temperature of water all nations have tacitly agreed to fix under a normal barometric pressure of 29·922 inches of mercury, having the temperature of melting ic...
In this thermometer a principle is used that has been long known to scientific men, viz. the affinity of mercury for platinum. If mercury be placed in contact with platinum under o...
Fig. 67. This instrument is composed of a shallow cylinder of steel, A, fig. 67, which is filled with mercury. Into the cylinder a thermometer, D, is introduced, the stem of which...
Bodies are said to possess the same temperature, when the amounts of heat which they respectively contain act outwardly with the same intensity of transfer or absorption, producing...
Either the prolonged effect of the atmospheric pressure upon the thin glass of the bulbs of thermometers, or the gradual restoration of the equilibrium of the particles of the glas...
Fig. 12. Fig. 12 gives a representation of these coast and fishery barometers. The frame is of solid oak, firmly screwed together. The scales are very legibly engraved on porcelain...
Thermometers for ascertaining the temperature of the sea at various depths are constructed to register either the maximum or minimum temperature, or both. The principle of each ins...
The pressure of the atmosphere affects the height of the tide, the water being in general higher as the barometer is lower. The expressions of seamen, that “frost nips the tide,” a...
The limits within which the ordinary barometric column oscillates, do not exceed four inches for extreme range, while the ordinary range is confined to about two inches; hence it h...
This barometer, with Fortin’s cistern, as arranged by Messrs. Negretti and Zambra, is an elegant, manageable, and very accurate instrument for travelling purposes, and well adapted...
Fig. 78. (Fig. 78) consists of a tube, C, made of silver, very thin, and perfectly polished; the tube is larger at one end than the other, the large part being 1·8 inches in depth...
The rain-gauge can be combined with clock-work and other mechanism so as to be self-recording of the amount of rain, the time, and duration of its fall. For the details of construc...
Fig. 24 represents the most accurate form of the Gay Lussac barometer. The short limb is closed at the top, after the mercury is introduced, and a small lateral), and here illustra...
Other forms of barometer (to be immediately described) have superseded this in the British Marine, but the French still give the preference to the wooden frames. They think the bar...
Rain gauges should be placed on the ground, in any position exposed to a free fall of rain, snow, or hail, where neither walls, buildings, nor trees shelter or cause eddies of wind...
The pressure of the atmosphere being measured by the barometer, it is evident that as the instrument is carried up a high mountain or elevated in a balloon, the length of the colum...
Those who possess a boiling-point thermometer should satisfy themselves that it has been correctly graduated. To do this, it is advisable to verify it with the reading of a standar...
Having considered how to make observations with the proper care and accuracy, it becomes necessary to know how to deduce the height by calculation. That a constant intimate relatio...
This barometer has been suggested to Messrs. Negretti and Zambra by Wentworth Erk, Esq. It consists of a regular barometer; but attached to the vernier is a double rack worked with...
Admiral FitzRoy deemed it desirable to construct a form of barometer as practically useful as possible for marine purposes. One that should be less delicate in structure than the K...