Primary Natural Philosophy, Designed for the Use of the Younger Class of LearnersC. Desilver, 1864 |
عبارات ومصطلحات مألوفة
apparent magnitude appear aqueous humor atmosphere attraction ball bottom burning-glass called camera lucida camera obscura candle centre clouds cold colors concave lens conductor current of electricity direction distance double convex lens downward earth effect excited explain fall feet figure filled fluid force freezing friction gases geographical pole glass gravity heat illustrated inches inclined plane instrument iron kind lenses LESSON lever Leyden jar liquid luminous body machine magic lantern magnet manner means meant mercury metal microscope moisture motion move needle north pole object OPTICS CONTINUED particles pass piece piston placed plane portion position pressure produced pulley rain rainbow ray of light reflecting telescope refraction represented retina rise screw seen shown side simply sound south pole substance surface temperature thermometer tube usually vapor velocity vessel of water vibrations visual angle voltaic pile warm weight wind wire zinc
مقاطع مشهورة
الصفحة 114 - The mountain-shadows on her breast Were neither broken nor at rest ; In bright uncertainty they lie, Like future joys to Fancy's eye.
الصفحة 57 - This result gives the weight of a bulk of water equal to that of the specimen, and by dividing the weight of the specimen in air by this number, the specific gravity is obtained.
الصفحة 69 - Fig. 27, the column being sustained by the pressure of the atmosphere upon the surface of the mercury in the shorter arm, the end of which is open. A small float of iron or glass rests upon the mercury in the shorter arm of the tube, and is suspended by a slender thread, which is passed round a wheel carrying an index.
الصفحة 114 - This is called the vitreous humor, (h.) 77. The object of this apparatus is to receive the rays of light, which diverge from all points of bodies placed before it, and to bring them again to a point upon the retina. It is a well-known fact, that when a ray of light passes obliquely from one medium to another of different density, it will be refracted or turned out of its course more or less, according to the difference of this density, and the obliquity at which the ray strikes the surface.
الصفحة 130 - ... IV. Armed with these terrestrial facts, the experimenter proceeds to examine the celestial phenomenon. He finds, on examining the sun's altitude and that of the summit of the bow, that the two vary inversely. The bow is always opposite the sun. A line may be drawn from the centre of the sun through the eye of the observer and the centre of the circle of which the bow is an arc to the sun's nadir. As one extremity of this line is depressed, the other is elevated. It becomes thus possible to compute...
الصفحة 101 - ... temperature of single days being found, •we may go on to determine the mean annual temperature, which is at the same time the mean heat of the place where the observations are made. The mean temperature of the year is very easily found, either by taking the average of all the daily observations, or by dividing the sum of the daily means by the number of days.
الصفحة 35 - simple pendulum," in which the bob is conceived to be a mere material particle, and the suspending rod is assumed to be devoid of mass, and the motion is assumed to be confined to some one vertical plane passing through the point of support, and all retarding influences, such as the resistance of the air and the friction at the point of support, are neglected. The "period of oscillation...
الصفحة 32 - That point in a body about which all the parts of the body exactly balance each other.
الصفحة 89 - Outdoors in the winter, why does a piece of metal feel colder than a piece of wood?
الصفحة 56 - The weight of the body as compared with the weight of an equal bulk of water.