United States Army Training ManualU.S. Government Printing Office, 1925 |
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absolute humidity adjustment air density Alfred Vail Allow no partial altitude ARMS ARMS Page artillery ballistic density ballistic wind barograph binding posts cloud có có có command Begin correct credit student determined dew point Directions for scoring dry bulb Equipment feet Figure Form horizontal hose cock hygrograph inches indicated inflated Information maximum ordinate maximum possible score measured mercurial barometer meridian METEOROLOGICAL OBSERVER miles per hour minimum score required minimum thermometer note and record partial score Pencil plotting board points precipitation pressure problem Procedure protractor psychrometer quadruple register questions rain gauge record sheet report at once required to pass scale short dotted line Signal Corps sling psychrometer snow sunshine recorder surface observations temperature theodolite thermograph thermometer tion tripod true north tube unit operations vernier vertical visibility weather weight wind direction wind speed wind vane wind velocity yards per minute Yards Yards Yards zero
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Página 347 - In connection with the installation of refrigerating plants, a knowledge of the highest temperatures experienced and the usual duration of excessively hot spells is of fundamental importance. The mean monthly rainfall, the time of freezing up, and of spring thawing are of prime importance to engineers in connection with road building, control and bridging of streams, and water supply. Transportation and all supply services are thus directly affected.
Página 333 - ... etc., respectively. If observations have been made of the temperature, barometric pressure, and vapor pressure at the levels specified the air density may be computed with the following formula: Where D is air density in grams per cubic meter b is station barometer reading in inches e is vapor pressure in inches of mercury t is temperature on Fahrenheit scale. After the actual air density has been computed for each of the levels named, these densities must each be reduced to the percentage of...
Página 348 - It is especially concerned with, whether or not it will have a clear field to land on when it returns. The clear nights usually chosen for such operations are frequently accompanied by early morning fogs. The forecaster's statement of the time the fog will begin may therefore determine which of several objectives will be chosen, since it determines the time available for the expedition. Squall and high-wind warnings are of especial interest to all Air Service units.
Página 346 - If a field for training in chemical warfare is to be installed in a given locality it is apparent that site "A," which has a great percentage of winds the speed of which is too high for the use of gas, is not so advantageous as site "B" perhaps not more than 10 or 20 km.
Página 346 - ... determine approximately the number of days in a year, season, or month in which ingress and egress are comparatively easy and safe. In a given locality this number may be very different for sites at no great distance apart since it is dependent chiefly on -surface conditions. Planes well in the air can take care of themselves under conditions which would result in crashes if they were near the ground in the act of landing. The layout of the field and the orientation of buildings and hangars in...
Página 310 - Knox, 1904. Longitude OED Distance east or west on the earth's surface, measured by the angle which the meridian of a particular place makes with some standard meridian. The meridian which is now almost universally used is that of Greenwich, London, which is considered as 0° and distance is recorded in degrees, minutes and seconds East and West Longitude.
Página 129 - CLOUDS Courtesy, US Department of Agriculture, Weather Bureau (1) Tufted cirrus, seen at Mt. Wilson, Cal. ; (2) Thin alto-stratus (lower right) transforming to growing alto-cumulus, which becomes merged into dense alto-stratus (lower left), seen at Tortosa. Spain; (3) Thin, undulated alto-stratus forming above a layer of fog or stratus (such thin A. St. is distinguished from cirrus-St.
Página 346 - Probably the installation most dependent on statistical meteorological information is the airdrome. Considering it as a harbor approached by aerial routes and affected by the direction and prevalence of winds, it is possible to determine approximately the number of days in a year, season, or month in which ingress and egress are comparatively easy and safe. In a given locality this number may be very different for sites at no great distance apart since it is dependent chiefly on surface conditions....
Página 334 - After the actual air density has been computed for each of the levels named, these densities must each be reduced to the percentage of standard density for the level at which each particular density was observed. This is done by dividing the observed density at a particular level by the standard density for that level. It is next necessary to compute the ballistic density from these percentage densities. This is done by multiplying the percentage densities found at the several levels by appropriate...
Página 349 - It is often quite possible to "pull off" safely effective local gas attacks when observations of the general air movement indicate conditions unfavorable for gas attack in the sector. This type of detailed shorttime forecast is better done at or near the place of the attack, but may be based upon carefully prepared topographic charts and done at some point farther to the rear.