Being arrived here, we are gotten within a little of the glorious God. The very next step we take must be into Him, who is the immediate cause of weight in matter. None but He producing, imprinting, preserving that property in matter, is to be now considered. We will go on to take notice of that property."

ESSAY XXI. Of GRAVITY.

To our globe there is one property so exceedingly and so generally subservient, that a very great notice is due to it; that is, gravity, or the tendency of bodies to the centre.

A most noble contrivance to keep the several globes of the universe from shattering to pieces, as they would else evidently do in a little time, through their swift rotation round their own axis. Our globe in particular, which revolves at the rate of above a thousand miles an hour, would, by the contrifugal force of that motion, be soon dissipated, into the circumambient space, were it not kept well together by this wondrous contrivance of the Creator, gravity, or the power of attraction. By this power also, all the parts of the globe are kept in their proper place and order; all bodies gravitating thereto unite themselves with, and preserve the bulk of them entire; and the fleeting waters are kept in their constant equipoise, remaining in the place which God has founded for them, a bound which He hath set, that they may not pass, that they turn not again to cover the earth. It is by the virtue of this glorious contrivance of the great God, who formed all things, that the observation of the Psalmist is perpetually fulfilled: thou rulest the raging of the

"There is another pathetic remark, made more than an hundred years ago, but worthy to be for ever thought upon; every creature, but only the wicked sinner, loves God more than it loves itself."

As we go along, we cannot well avoid speaking of cohesion. We see two very plain, smooth, well polished bodies, will firmly cohere, even in an exhausted receiver. This renders it evident, that cohesion is not owing to the gravity, nor to any other property of the air. What appears in the surfaces of cohering bodies upon their breaking, shows us, that a necessary condition of cohesion is a congruity of surfaces; and such as excludes any fluid from lying between them. We may suppose, with Dr. Cheyne, that some of the primary atoms, whereof bodies are constituted, are terminated with plain and smooth surfaces on all sides; which will produce bodies of the strongest cohesion: others are partly terminated with plain and smooth; and partly with curve surfaces, which will produce bodies of a meaner cohesion. Others are entirely terminated with curve surfaces, which will produce fluids, and be. tween these entirely plain and smooth, and entirely curve, there are infinite combinations of surfaces, plain, and smooth, and curve, which will account for all the various degrees of cohesion in bodies, in respect of their figures. But now the cement, which hinders the separation of bodies, when the points of their surfaces are brought into contact; this, can be nothing but the universal law of attraction, whereby all the parts of matter endeavour to embrace one another, and cannot be separated but by a force, that shail be superior to that by which they attract,

The very next step who is the immediate None but He pro

Being arrived here, we are gotten within a little of the glorious God. we take must be into Him, cause of weight in matter. ducing, imprinting, preserving matter, is to be now considered. to take notice of that property."

that property in
We will
We will go on

ESSAY XXI. Of GRAVITY.

To our globe there is one property so exceedingly and so generally subservient, that a very great notice is due to it; that is, gravity, or the tendency of bodies to the centre.

A most noble contrivance to keep the several globes of the universe from shattering to pieces, as they would else evidently do in a little time, through their swift rotation round their own axis. Our globe in particular, which revolves at the rate of above a thousand miles an hour, would, by the contrifugal force of that motion, be soon dissipated, into the circumambient space, were it not kept well together by this wondrous contrivance of the Creator, gravity, or the power of attraction. By this power also, all the parts of the globe are kept in their proper place and order; all bodies gravitating thereto unite themselves with, and preserve the bulk of them entire; and the fleeting waters are kept in their constant equipoise, remaining in the place which God has founded for them, a bound which He hath set, that they may not pass, that they turn not again to cover the earth. It is by the virtue of this glorious contrivance of the great God, who formed all things, that the observation of the Psalmist is perpetually fulfilled: thou rulest the raging of the

sea; when the waves thereof arise, thou stillest them.

Very various have been the sentiments of the curious, what cause there should be assigned for this great and catholic affection of matter, the vis centripeta: I shall wave them all, and bury them in the place of silence, with the materia striata of Des Cartes, which our Keil has very sufficiently brought to nothing; and perhaps the fluid of Dr. Hook must go the same way. It is enough to me what that incomparable mathematician, Dr. Halley, has declared upon it: that after all, gravity is an effect insolvable by any philosophical hypothesis; it must be religiously resolved into the immediate will of our most wise Creator, who by appointing this law, throughout the material world, keeps all bodies in their proper places and stations, which without it would soon fall to pieces, and be utterly destroyed.

All bodies descend still towards a point, which either is, or lies near to, the centre of the globe. Should our Almighty God change that centre but the two thousandth part of the radius of our globe, the tops of our highest mountains would be soon laid under water.

In all places equi distant from the centre of our globe, the force of gravity is nearly equal. Indeed, as it has been proved by Sir Isaac Newton, the equatorial parts are something higher than the polar parts; the difference between the earth's diameter and axis being about thirty four English

miles.

Gravity equally effects all bodies. The absolute gravity of all is the same. Abstracting from the resistance of the medium, the most compact

and the most diffuse, the greatest and the smallest, would descend an equal space in an equal time. In an exhausted receiver a feather will descend as fast as a pound of lead. But this resistance of the medium has produced a comparative gravity. And upon the difference of specific gravity in many bodies, the observations of our philosophers have been very curious.

According to the exquisite Halley and Huygens, the descent of heavy bodies is after the rate of about sixteen feet in one second of time.

Nevertheless this power increases as you descend to, decreases as you ascend from the centre of the globe, and that in proportion to the squares of the distances therefrom reciprocally; as, for instance, at a double distance to have but a quarter of the force. A ton weight on the surface of the earth, raised heaven-wards to the height of one semidiameter of the earth from hence, would weigh but one quarter of a ton. At three semidiameters from the surface of the earth, it would be as easy for a man to carry a ton, as here to carry little more than an hundred pounds. At the distance of the moon, which suppose to be sixty semidiameters of the earth, 3600 pounds weight but one pound; and the fall of bodies is but sixteen feet in a whole minute.

I remember I have somewhere met with such a devout improvement of this observation: "The further you fly towards heaven, the more (if I may use the Falconers word) you must lessen. There is great reason why it should be so. Defamations

particularly will be things by which you must be lessened: you must meet with heavy things; defamations are in a singular manner such; they