Directions for Meteorological Observations, and the Registry of Periodical PhenomenaSmithsonian institution, 1858 - 70 من الصفحات |
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عبارات ومصطلحات مألوفة
Actaea ADDITIONAL OBSERVATIONS adjustment appearance arch ascertain atmosphere aurora aurora borealis baneberry boxwood bulb canadensis capillarity cirrus cistern clouds coincide corona correction covered Crataegus degrees diameter direction divisions entered estimate exactly Fahrenheit fall fastened feet fraction funnel gage German silver glass cylinder ground HARVARD COLLEGE heat height horizontal hour hundredths inch of rain indicated inserted instru instrument Integers omitted ivory point journal L.-Common layer leaf light magnet marked maxima and minima means ment mercurial column meteor millimetres motion necessary noted OBSERVATIONS DURING STORMS ombrometer Parhelia PERIODICAL PHENOMENA plate position psychrometer quantity rain-gage record rection ring scale screw sheet side signify Smithsonian Institution snow snow-gage spirit-thermometer streamers summit surface suspended taken temperature tenths thermometer thirty inches thousandths tion tube vane vapor vernier vertical vessel Viburnum wind wind-vane window wooden zero
مقاطع مشهورة
الصفحة 57 - G, i, j, and k, are of boxwood ; the other parts of brass or German silver. The screw O serves to adjust the mercury to the ivory point, and also, by raising the bag, so as to completely fill the cistern and tube with mercury, to put the instrument in condition for transportation."* 11 § 6.
الصفحة 57 - G, through the neck of which the barometer tube / passes, and to which it is fastened by a piece of kid leather, making a strong but flexible joint. To this plate, also, is attached a small ivory point h, the extremity of which marks the commencement or zero of the scale above.
الصفحة 11 - ... inches, and on which the barometer is suspended. The instrument remains generally in the box, which is closed by a movable cover, and which protects it from external injuries, from dust, and from the direct radiation of warm bodies, or the currents of air from the window, and diminishes the effect of the too sudden variations of temperature. When it is to be observed, the barometer is taken by the upper end of the tube, and the suspending...
الصفحة 26 - N. NNE. NE. ENE. E. ESE. SE. SSE. S. SSW. SW. WSW. W. WNW. NW. NNW.
الصفحة 26 - The observation of the vane requires more care than is usually given. In winds of considerable strength the vane is never at rest, or fixed in the same direction; it oscillates incessantly, and its oscillations increase in extent with certain winds and with the violence of the wind. In such cases observers must note the mean direction 'between the extremes. When the wind is too light to move the vane, and when it is calm, no direction will be...
الصفحة 49 - THOUGH the aurora boreal is has received attention during a considerable portion of the last two centuries, definite information is still wanting on several points which may serve as the basis of a sound induction as to its cause. These relate particularly to the actual frequency of...
الصفحة 26 - When the index is immovable, and there is no oscillation, we must give up its indications, and refer to the movement of light bodies, as that of the leaves of trees and the smoke of chimneys, to determine the direction of these feeble currents of air. During the night the direction of the wind may be easily ascertained by raising the hand in the air, with one finger wet. The least motion in the air increases evaporation, and a sensation of cold is experienced on the side of the finger turned towards...
الصفحة 50 - Auroral corona, or a union of beams south of the zenith. 8. Dark clouds accompanying the diffuse light. 9. Sudden appearance of haze over the whole face of the sky.
الصفحة 57 - B by means of four long screws P and the ring R; on the ring R screws the cap S, which covers the lower parts of the cistern, and supports at the end the adjusting screw O.
الصفحة 12 - ... the end of the hook. The instrument is then in the full light of the window, in front of which the observer places himself; the summit of the mercurial column, as well as the surface of the mercury in the cistern, are completely lighted, and the reading becomes easy and certain. Moreover, the slight oscillating movement impressed on the instrument, by changing its place, breaks the adherence of the mercury to the glass, and thus prepares a good observation. After the reading, the barometer is...