several hundred miles high; which is easy to be admitted, when we consider what he proves in another part of the same treatise, viz. that the air here about the surface of the earth, when the pressure is taken from it, will dilate itself about 152 times. The atmosphere is the scene of the meteors; and therein is collected the matter of rain, hail, snow, thunder and lightning; and a great many other things observable in the air. CHAP. VI. OF METEORS IN GENERAL. BESIDES the springy particles of pure air, the atmosphere is made up of several steams or minute partcles of several sorts, rising from the earth and the waters, and floating in the air, which is a fluid body, and though much finer and thinner, may be considered in respect of its fluidity to be like water, and so capable, like other liquors, of having heterogenious particles floating in it. The most remarkable of them are, first, the particles of water raised into the atmosphere, chiefly by the heat of the sun, out of the sea and other waters, and the surface of the earth; from whence it falls in dew, rain, hail, and snow. Out of the vapours rising from moisture, the clouds are principally made. Cloulds do not consist wholly of watery parts; for, besides the aqueous vapours that are raised into the air, there are also sulphureous and saline N particles that are raised up, and in the clouds mixed with the aqueous particles, the effects whereof are sometimes very sensible; as particularly in light-ning and thunder, when the sulphureous and nitrous particles firing break out with that violence of light and noise, which is observable in thunder, and very much resembles gun-powder. That there are nitrous particles raised into the air is evident from the nourishment which rain gives to vegetables more than any other water; and also by the collection of nitre or salt-petre in heaps of earth, out of which it has been extracted, if they be exposed to the air, so as to be kept from rain; not to mention other efforts, wherein the nitrous spirit in the air shews itself. Clouds are the greatest and most considerable of all the meteors, as furnishing matter and plenty to the earth. They consist of very small drops of water, and are elevated a good distance above the surface of the earth; for a cloud is nothing but a mist flying high in the air, as a mist is nothing but a cloud here below. How vapours are raised into the air in invisible steams by the heat of the sun out of the sea and moist parts of the earth, is easily understood; and there is a visible instance of it in ordinary distillations. But how these steams are collected into drops, which bring back the water again, is not so easy to determine. To those that will carefully observe, perhaps it will appear probable, that it is by that which the chymists call precipitation; to which it answers in all its parts. The air may be looked on as a clear and pellucid menstruum, in which the insensible particles of dissolved matter float up and down, without being discerned, or troubling the pellucidity of the air; when on a sudden, as if it were by a precipitation, they gather into the very small but visible misty drops that make clouds. This may be observed sometimes in a very clear sky, when, there not appearing any cloud, or any thing opake, in the whole horizon, one may see on a sudden clouds gather, and all the hemisphere overcast; which cannot be from the rising of the new aqueous vapours at that time, but from the precipitation of the moisture that in invisible par ticles floated in the air, into very small, but very visible drops, which by a like cause being united into great drops, they become too heavy to be sustained in the air, and so fall down in rain. Hail seems to be the drops of rain frozen in their falling. Snow is the small particles of water frozen before they unite into drops. The regular figures, which branch out in flakes of snow, seem to show that there are some particles of salt mixed with the water, which makes them unite in certain angles. The rainbow is reckoned one of the most remarkable meteors, though really it be no meteor at all; but the reflection of the sun-beams from the smallest drops of a cloud or mist, which are placed in a certain angle made by the concurrence of two lines, one drawn from the sun, and the other from the eye to these little drops in the cloud, which reflect the sun-beams; so that two people, looking upon a rainbow at the same time, do not exactly see the same rainbow. CHAP. VII. OF SPRINGS, RIVERS, AND THE SEA. PART of the water that falls down from the clouds, runs away upon the surface of the earth into channels, which convey it to the sea; and part of it is imbibed in the spungy shell of the earth, from whence sinking lower by degrees, it falls down into subteranean channels, and so under ground passes into the sea; or else, meeting with beds of rock or clay, it is hindered from sinking lower, and so breaks out in springs, which are most commonly in the sides, or at the bottom of hilly ground. Springs make little rivulets: those united makes brooks: and those coming together makes rivers, which empty themselves into the sea. The sea is a great collection of waters in the deep valleys of the earth. If the earth were all plain, and had not those deep hollows, the earth would be all covered with water; because the water, being lighter than the earth, would be above the earth, as the air is above the water. The most remarkable thing in the sea is, that motion of the water called tides. It is a rising and falling of the water of the sea. this is the attraction of the moon, The cause of whereby the part of the water in the great ocean, which is nearest the moon, being most strongly attracted, is raised higher than the rest; and the part opposite to it on the contrary side, being least attracted, is also higher than the rest. And these two opposite rises of the surface of the water in the great ocean, following the motion of the moon from east to west, and striking against the large coasts of the continents that lie in its way; from thence rebounds back again, and so make floods and ebbs in narrow seas, and rivers remote from the great ocean. Herein we also see the reason of the times of the tides, and why they so constantly follow the course of the moon. CHAP. VIII. OF SEVERAL SORTS OF EARTH, STONES, ME TALS, MINERALS, AND OTHER FOSSILS. THIS solid globe we live upon is called the earth, though it contains in it a great variety of bodies, several whereof are not properly earth, which word, taken in a more limited sense, signifies such parts of this globe as are capable, being exposed to the air, to give rooting and nourishment to plants, so that they may stand and grow in it. With such earth as this, the greatest part of the surface of this globe is covered; and it is as it were the store-house, from whence all the living creatures of our world have originally their provisions; for from thence all the plants have their sustenance; and some few animals, and from these all the other animals. Of earth, taken in thi sense, there are several |