Outlines of Natural Philosophy: Being Heads of Lectures Delivered in the University of Edinburgh, Volume 1

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A. Neill & Company, 1812 - 309 pages

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Page 165 - ... once what is the weight of a quantity of water, equal in bulk to the solid matter in the sand ; and by comparing this with the weight of the sand, we have its true specific gravity.
Page 121 - The space through which a body will descend on an inclined plane, is to the space through which it would fall freely in the same time, as the sine of the inclination of the plane to the...
Page 156 - A light triangle has two equal sides. Its hypothenuse is 100 rods long, (a) Find one of its two equal sides, (b) Find its area. 33. What is the ratio of the area of a circle to the area of its circumscribed square ? 34. What is the ratio of the square of the radius to the square of the diameter of the same circle ? 35. A man's tax is $37.50.
Page 227 - From the foregoing statements it may be safely inferred that " the mean height of the barometer at the level of the sea being the same in every part of the globe...
Page 185 - ... to the height of the surface of the fluid above the orifice, a result fiist stated by Torricelli, and adopted by him as a principle, ( De motu Projectorum, Florent.
Page 189 - Let V be the velocity of the stream, measured by the inches it moves over in a second; R a constant quantity, viz. the quotient obtained by. dividing the area of the transverse section of the stream, expressed in square inches, by the boundary or perimeter of that section, minus the superficial breadth of the stream, expressed in linear inches. The mean velocity is that with which, if all the particles were to move, the discharge would be the same with the actual discharge.
Page 87 - For if a screw thus formed be placed obliquely, so as to make with the vertical, an angle equal to that which the spiral makes with the lines parallel to the axis, there will be in each turn of the spiral a part parallel to the horizon, where, if a body were placed, it would be at rest If, then, the screw be turned, the body will ascend, because the part of the screw behind it becomes more inclined than the part before it, so that the body is urged forward and consequently ascends.
Page 189 - Water running in open canals, or in rivers, is accelerated in consequence of its depth, and of the declivity on which it runs, till the resistance, increasing with the velocity, becomes equal to the acceleration, when the motion of the stream becomes uniform. It is evident that the amount of the resisting forces can hardly be determined by principles already known, and therefore nothing remains but to ascertain, by experiment, the velocity corresponding to different declivities, and different depths...
Page 117 - If the machine is very lightly loaded, it may give great velocity to the load ; but from the smallness of its quantity, the effect may still be very inconsiderable, consequently between these two loads there must be some intermediate one that will render the effect the greatest possible. This is equally true in the application of animal strength as in machines.
Page 292 - ... currents of air occasioned by the disturbance of the equilibrium of the atmosphere by the unequal distribution of heat. The general tendency, in such circumstances, is for the heavier columns to displace the lighter ; and for the air at the earth's surface to move from the poles toward the equator : in consequence of the rotation of the earth on its axis, another motion is combined with the currents just described. The air, which is constantly moving from points where the earth's motion on its...

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