Lectures on natural philosophy the result of many years' practical experience of the facts elucidated. With an appendix: containing, a great number and variety of astronomical and geographical problems. Also some useful tables, and a comprehensive vocabulary / [Margaret Bryan].

  • Bryan, Margaret, active 1815.
Date:
1806
Catalogue details

Licence: Public Domain Mark

Credit: Lectures on natural philosophy the result of many years' practical experience of the facts elucidated. With an appendix: containing, a great number and variety of astronomical and geographical problems. Also some useful tables, and a comprehensive vocabulary / [Margaret Bryan]. Source: Wellcome Collection.

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    weight, the heavier will move slower than the lighter one; that is, their motions will be in the reciprocal pro])ortion to their weights; the motion of each being in the inverse proportion of the quantity of matter in each body. If two pieces of cork be placed nearer to the edge of the bason than to each other, they will be attracted by the bason, and drawn from each other, close to the edge of it. By the power or force of gravity, all bodies, when free to move, fall towards the centre of our earth; which force causes them to press the hand that stops their progress, and makes them fall in lines perpendicular to the horizon when sutfered to proceed. Some of the ancient philosophers,, being unacquainted with the laivs of gravity, and perceiving that some light bodies rose in the air, thought there were two principles in bodies: one, by which lighter bodies tended upwards from the earth; and another, by which heavier ones de- scended towTirds it. It was Galileo who discovered that all bodies fell towards our Earth; and that it was the different specific gravities* of the bodies, with the medium through which they passed, that caused the difference in their descent; for in an unresisting medium, he perceived they fell towards the Earth with equal velocity. This assertion w^e shall prove by experiment, when we treat of the re- sistance and other properties of Air. It has been long disputed, wdiether there be a property of re- pulsion as well as of attraction in bodies; which, perhaps, we are ^ Specific gravity is the diflference of weight between two bodies of equal size, but of different densities.