Elementary physiography, adapted to the syllabus of the South Kensington science departmentW. & R. Chambers, 1881 - 166 lappuses |
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ascend Atlantic atmosphere attraction barometer becomes binary compounds bismuth body bottom called carbonate of lime carbonic acid cause chemical affinity climate cloud coal coast cohesion cold colder condensation cooled crust CURRENT ELECTRICITY deposited depth distance earth earthquake effect electricity elements energy equator equatorial evaporation fall fathoms feet flow fluid force freezing galvanic gases glacier glass globe gravity Gulf Stream heat heat-rays hydrogen igneous igneous rocks iron island land latent heat lava layers less light limestone liquid magnet mass matter melting mercury metal miles minerals molecules molten motion nitrogen ocean ounces oxide oxygen particles polar poles portion pressure produced quartz radiation rain rainfall rays Reading-Book reefs regions rise rocks seen side silica solid stone strata stratum stream substance summer surface temperature thermometer tion tricity tube vapour velocity volcanoes waves weight whole wind wire
Populāri fragmenti
155. lappuse - It may be doubted whether there are many other animals which have played so important a part in the history of the world, as have these lowly organized creatures.
99. lappuse - Hebrides, the north of Norway, and Spitzbergen. But this is accounted for by the general flow of the surfacewater towards the poles, forming part of the vertical oceanic circulation ; a flow which receives an eastward deflection as it proceeds northwards, in the way above explained. This general set of the surface-water...
47. lappuse - Dense bodies are generally the best conductors ; light and porous ones the worst. Feathers, down, fur, flannel, and most of the fabrics used for winter dresses, owe their so-called warmth to their low-conducting power for heat. Their action is altogether negative, being limited to the prevention of the rapid escape of heat generated by the living beings whose bodies they cover. Hence the best...
56. lappuse - ... ohm in line resistance makes a large error in the reading. Another way of stating the same thing is to say that a millivoltmeter measures the potential drop across its own resistance and the larger the ratio of its own to the total resistance the smaller the percentage error introduced by a given change in total resistance.
45. lappuse - Fahrenheit chose the temperature of 32° below freezing as the zero-point of his scale, because it was the lowest that had then been observed, and was considered to indicate the complete absence of heat ; but it is now known that there are natural temperatures at least 90° below this; and by artificial mixtures, a cold has been produced of —-146° F.
50. lappuse - The rate of cooling of a hot solid body, so far as radiation is concerned, is remarkably influenced by the state of its surface, and in the case of liquids and gases, by the state of the surface of the vessels containing them. Thus, hot water placed in a tin vessel coated externally with lampblack, cools twice as fast as it does in a bright tin vessel. Similarly, if two metallic vessels be taken, the one left bright, and the other covered with linen, hot water will be found * to cool much faster...
51. lappuse - Absorption and reflection of rays of heat.— Rays of heat follow almost the same laws as to reflection, absorption, refraction, &c., as rays of light (see OPTICS). When they fall on the surface of a body, they either enter it or are reflected. Those, again, that enter are either transmitted, like light through glass, or are retained and absorbed. It is only the rays that are absorbed that warm the body; those that are reflected off, as well as those that are transmitted, produce no effect on the...
110. lappuse - ... declination ; so that the whole diurnal change in any one of the elements, and at any station, is made up of two portions, one of which retains the same sign, and a constant coefficient all the year round ; the other changes sign, and varies in the value of its coefficient with the annual movement of the sun from one side of the equator to the other. That...
18. lappuse - Adhesion of liquids to solids takes place much more readily than that of solids to solids, because in the case of a liquid and a solid the surfaces come into more complete contact. When the hand or a rod of metal is dipped into water, a film of the water adheres to the surface, and is borne up against its own weight; nor can any force shake it all off. Plunge a bit of gold, or silver, or lead, into mercury, and a •portion of the mercury will in like manner adhere. Wherever we have wetting, we have...
48. lappuse - They conduct heat very slowly, as may be proved by applying heat to the top of an air-tight glass vessel with a thermometer suspended a little below the heated portion. But when the heat is applied from below, currents of circulation immediately begin, as in the case of a liquid.