Library of Useful Knowledge: Natural philosophy, المجلد 3

الغلاف الأمامي
 

ما يقوله الناس - كتابة مراجعة

لم نعثر على أي مراجعات في الأماكن المعتادة.

طبعات أخرى - عرض جميع المقتطفات

عبارات ومصطلحات مألوفة

مقاطع مشهورة

الصفحة 70 - If two triangles have one angle of the one equal to one angle of the other and the sides about these equal angles proportional, the triangles are similar.
الصفحة 2 - ... invisible. These animals are of a great variety of shapes and sizes, and in such prodigious numbers, that, in a short time, the whole surface of the rock appears to be alive and in motion. The most common...
الصفحة 155 - D'Alembert, was the Precession of the equinoxes and the Nutation of the earth's axis, according to the theory of gravitation.
الصفحة 31 - The lowest and most level parts of the earth, when penetrated to a very great depth, exhibit nothing but horizontal strata composed of various substances, and containing almost all of them innumerable marine productions. Similar strata, with the same kind of productions, compose the hills even to a great height. Sometimes the shells are so numerous as to constitute the entire body of the stratum. They are almost...
الصفحة 2 - The examination of a coral reef during the different stages of one tide, is particularly interesting. When the tide has left it for some time it becomes dry, and appears to be a compact rock, exceedingly hard and ragged ; but...
الصفحة 18 - Scotland was divided into two provinces — the one on the north, and the other on...
الصفحة 185 - ... the squares of the periodic times are as the cubes of the distances from the common centre, the centripetal forces will be inversely as the squares of the distances.
الصفحة 19 - ... they pass rapidly along the surface of the sea, and continue a quarter of an hour or more before they disappear. A notion has been entertained that they are very dangerous to shipping, owing to the descent, at the instant of their breaking, of a large body of water sufficient to sink a ship ; but this does not appear to be the case, for the water descends only in the form of heavy rain.
الصفحة 31 - On the barren flank of a rock grows a tree with coriaceous and dry leaves. Its large woody roots can scarcely penetrate into the stone. For several months of the year, not a single shower moistens its foliage. Its branches appear dead and dried; but when the trunk is pierced, there flows from it a sweet and nourishing milk. It is at the rising of the sun that this vegetable fountain is most abundant. The blacks and natives are then seen hastening from all quarters, furnished with large bowls to receive...
الصفحة 19 - Whirlwinds sometimes arisfi from winds blowing among lofty and precipitous mountains, the form of which influences their direction, and occasions gusts to descend with a spiral or whirling motion. They are frequently, however, caused by two winds meeting each other at an angle, and then turning upon a centre. When two winds thus encounter one another, any cloud which happens to be between them is of course condensed and turned rapidly round ; and all substances sufficiently light are carried up into...

معلومات المراجع