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sinks so deep as to displace 50000 cubic feet of fresli water; what is the whole weight of the vessel ?

Ans. 13957. tons. QUEST. 63. It is required to determine what would be the height of the atmosphere, if it were every where of the şame density as at the surface of the earth, when the quickșilver in the barometer stands at 30 inches; and also, what would be the height of a water barometer at the same time?

Ans. height of the air 29166į feet, or 5.5240 miles,

height of water 35 feet. Quest. 64. With what velocity would each of those three fluids, viz. quicksilver, water, and air, issae through a small orifice in the bottom of vessels, of the respective heights of 30 inches, 35 feet, and 5-5240 miles, estimating the pressure by the whole altitudes, and the air rushing into a vacuum ?

Ans. the veloc. of quicksilver 12.681 feet.

the veloc. of water 47.447
the veloc. of air

1369.8 QUEST. 65. A very large vessel of 10 feet high (no matter what shape) being kept constantly full of water, by a. large supplying cock at the top; if 9 small circular holes, each of an inch diameter, be opened in its perpendicular side at every foot of the depth: it is required to determine the several distances to which they will spout on the horizontal plane of the base, and the quantity of water discharged by all of them in 10 minutes ?

Ans. the distances are

✓ 36 or 6.00000
1/64 - 8.00000
♡ 84 - 9:16515

9.79796
7100 - 10.00000
Ņ96

9:79796
9:16515
8.00000

6.00000
and the quantity discharged in 10 min, 123.8849 gallons.

Note. In this solution, the velocity of the water is supposed to be equal to that which is acquired by a heavy body in falling through the whole height of the water above the orifice, and that it is the same in every part of the holes,

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Quest. 66. If the inner axis of a hollow globe of copper, exhausted of air, be 100 feet; what thickness must it be of, that it may just float in the air?

Ans. '02688 of an inch thick. QUÉST. 67. If a spherical balloon of copper, of 16o of an inch thick, have its cavity of 100 feet diameter, and be filled with inflammable air, of t of the gravity of common air, what weight will just balance it, and prevent it from rising up into the atmosphere?

Ans. 212731b. QUEST. 68. If a glass tube, 36 inches long, close at top, be sunk perpendicularly into water, till its lower or open end be 30 inches below the surface of the water; how high will the water rise within the tube, the quicksilver in the common barometer at the same time standing at 294 inches ?

Ans. 2.26545 inches. QUEST. 69. If a diving bell, of the form of a parabolic conoid, be let down into the sea to the several depths of 5, 10, 15, and 20 fathoms; it is required to assign the respective heights to which the water will rise within it: its axis and the diameter of its base being each 8 feet, and the quicksilver in the barometer standing at 30:9 inches? Ans. at 5 fathoms deep the water rises 2.03546 feet. at 10

3.06393 at 15

3:70267 at 20

4:14658

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QUEST. 63. It is required to deter FLUXIONS. height of the atmosphere, if it " same density as at the surface of șilver in the barometer stands

AND PRINCIPLES. would be the height of a w?

Ans. height of th
height of

of Fluxions, magnitudes or quan Quest. 64. With considered, not as made up of a number three fluids, viz. was generated by continued motion, by a small orifice in they increase or decrease. As, a line by heights of 30 ;

a surface by the notion of a line;

the motion of a surface. So likewise, time into a vacu'

represented by a line, increasing unimotion of a point. And quantities of all ever, which are capable of increase and decrease, Like manner be represented by geometrical magni

conceived to be generated by motion. tey

Any quantity thus generated, and variable, is called a wcording to which any flowing quantity increases, at any svent, or a Flowing Quantity. And the rate or proportion

or instant, is the Fluxion of the said quantity, at that

or instant ; and it is proportional to the magnitude which the flowing quantity would be uniformly increased in a given time, with the generating celerity uniformly continued during that time.

3. The small quantities that are actually generated, produced, or described, in any small given time, and by any continued motion, either uniform or variable, are called Increments.

4. Hence, if the motion of increase be uniform, by which increments are generated, the increments will in that case be proportional, or equal, to the measures of the fluxions : but if the motion of increase be accelerated, the increment so generated, in a given finite time, will exceed the fluxion : and if it be a decreasing motion, the increment, so generated, will be less than the fluxion. But if the time be indefinitely small, so that the motion be considered as uniform for that instant; then these nascent increments will always be proportional, or equal, to the fluxions, and may be substituted instead of them, in any calculation,

position

position

by

a

Quest. 66. If the inner axis of.a hollow globe of copper, exhausted of air, be 100 feet; what thickness' must it be of, that it may just float in the air?

Ans. *02688 of an inch thicki QUEST. 67. If a spherical balloon of copper, of 16 of an inch thick, have its cavity of 100 feet diameter, and be filled with inflammable air, of ty of the gravity of common air, what weight will just balance it, and prevent it from rising up into the atmosphere?

Ans. 21273lb. QUEST. 68. If a glass tube, 36 inches long, close at top, be sunk perpendicularly into water, till its lower or open end be 30 inches below the surface of the water; how high will the water rise within the tube, the quicksilver in the common barometer at the same time standing at 29 inches ?

Ans. 2•26545 inches. QUEST. 69. If a diving bell, of the form of a parabolic conoid, be let down into the sea to the several depths of 5, 10, 15, and 20 fathoms; it is required to assign the respective heights to which the water will rise within it: its axis and the diameter of its base being each 8 feet, and the quicksilver in the barometer standing at 30:9 inches ?

Ans. at 5 fathoms deep the water rises 2.03546 feet. at 10

3.06393

3.70267 at 20

4.14658

at 15

The

THE DOCTRINE OF FLUXIONS.

DEFINITIONS AND PRINCIPLES.

a

a

Art. 1. In the Doctrine of Fluxions, magnitudes or quan, tities of all kinds are considered, not as made up of a number of small parts, but as generated by continued motion, by means of which they increase or decrease. As, a line by the motion of a point; a surface by the motion of a line; and a solid by the motion of a surface. So likewise, time may be considered as represented by a line, increasing uniformly by the motion of a point. And quantities of all kinds whatever, which are capable of increase and decrease, may in like manner be represented by geometrical magnitudes, conceived to be generated by motion.

2. Any quantity thus generated, and variable, is called a Fluent, or a Flowing Quantity. And the rate or proportion according to which any flowing quantity increases, at any position or instant, is the Fluxion of the said quantity, at that position or instant; and it is proportional to the magnitude by which the flowing quantity would be uniformly increased in a given time, with the generating celerity uniforınly continued during that time.

3. The small quantities that are actually generated, produced, or described, in any small given time, and by any continued motion, either uniform or variable, are called In

crements.

4. Hence, if the motion of increase be uniform, by which increments are generated, the increments will in that case be proportional, or equal, to the measures of the fluxions: but if the motion of increase be accelerated, the increment so generated, in a given finite time, will exceed the fluxion : and if it be a decreasing motion, the increment, so generated, will be less than the fluxion. But if the time be indefinitely small, so that the motion be considered as uniform for that instant; then these nascent increments will always be proportional, or equal, to the fuxions, and may be substituted instead of them, in any calculation,

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