Page 15
O U TF LOW OF W A T ER
1 Five cylindrical brass vessels of different heights and openings in the bases,
and a similar vessel without opening, to experiment on the times in which the
vessels empty under various conditions, and on the amounts run out in given
times, ’s Gravesande, LV, fig. 1,2.
2 The water trough o f’s Gravesande, to show the sideways pressure of moving
water, ’s Gravesande, LVIII, fig. 1, 2.
0 The apparatus of Segner, which revolves when the water flows out sideways
from one side of the same horizontal tubes.
4 A double syringe or two united syringes with two different sets of discharge
tubes — in one the openings cross one another, in the other they are parallel
so that they only touch one another — to experiment on how far different
liquids that are simultaneously expressed, each from a separate syringe, are
mixed together in the one case or in the other, ’s Gravesande, LV, fig. 7, 8.
Page 16
MODELS OF MILLS AND MACHINES W ITH W H ICH TO R A IS E W A T ER
1 A model of a common scoop-wheel mill by Catz.
2 A model of a screw or Archimedean-screw mill, in which the mill rods are
according to Spille and the sails according to Van Dijl, by Gatz.
f 3 A model of a common tail-mill or water-mill, which is turned to the wind
automatically, by Gatz.
t 4 A model of a Krultrekrad [curl wheel] after Wheeler, which discharges at the
axle, and is employed by Hartzink in the Diemer lake.
t 5 A model of a chain-pump composed of scoops, by which the water is raised,
by Catz. - 1
6 A model of the machine of Vera, in which the water is raised alqng an ascending
rope.
t 7 A model of a water-ram of Montgolfier, with its water-trough and lead pipe.
Page 17
S P E C IF IC G R A V IT Y
Weighing of Solid Bodies
1 A complete apparatus for doing specific gravity experiments, partly in a
small box, by Pauw \_sic], according t o ’s Gravesande, XLIX, completely,
and LXX [should read LII], completely.
■j- 2 An accurate die [taarling] of brass of 3 inches, in a small shagreen box.
3 The specific gravity apparatus of Nicholson, to weigh solid bodies.
4 The gravimeter of Guyton made of glass, to weigh solid bodies and also liquids,
see Annales de Chimie, XXI, p. 1.
Page 18
W E IG H IN G OF L IQ U ID S
-j- i The common hydrometer or spirit-prover of glass.
2 The hydrometer of Fordyce by Dollond, in a small box.
3 The universal aerometer or hydrometer of Schmidt and Ciarcy, see Gren’s
Journal der Physik, 7th part, 2nd volume.
4 An apparatus to test the specific gravity of six liquids at the same time, consisting
of six vertical glass tubes from a brass horizontal tube, in which the air
is evacuated by a syringe according to Nollet, ii, leçon 7, VII, fig. 37.
t 5 Four different liquids in a closed glass tube, which are differentiated from
each other by their different weights.
■f 6 An apparatus to show how the wine remains separate from water because of
its lesser weight.
Page 19
A ERO LO G Y
I i The common double air-pump with valves by J. Paauw, with the long and
short mercury tubes and tightening screws. With it, a small table on which
the pump can be screwed.
•j- 2 The double air-pump of John Cuthbertson, described in his Description of
an Improved Air-pump, Amst. 1787.
3 A single air-pump of which the pump is 3J inches wide and ... inches high,
being the pump of Senguerd, placed vertically, with many improvements,
according to the order of Van Marum constructed by A .Watt in Amsterdam
1793, This pump is also a pressure-pump; see the description of the same in
the 10th volume of the Verhandelingen van Teylers Genootschap.
Page 20—21
TH E FO R C E OF E X PAN SIO N (E L A S T IC IT Y ) OF A IR
1 A glass bell-jar, with a hook at the top to suspend a bladder containing a little
air.
2 A glass, in which a bladder is compressed by the expansion of the air which is
trapped between the sides of the glass, Desaguliers, ii, XL, fig. 7.
j 3 A small glass ball with a long neck, standing in a small glass, to demonstrate
the expansion of an air bubble.
| 4 A ring of glass on which can be placed an egg, when one wants to demonstrate
the expansion of the air trapped between the membrane and the shell.
5 A small bottle, in which stands one limb of a glass syphon, and from which
the liquid, with which the small bottle is half filled, is forced out by the expansion
of the air enclosed in the small bottle. With this, a small open bottle
of the same size in which the other limb of the syphon is placed.
6 A glass partly filled with mercury, in which is placed a glass tube, which is
open at the top, and in which the mercury moves upwards by means of the
expansion of the air enclosed in the small bottle.
f 7 Thin, square, small bottles, which, because of the expansion of the air in
highly evacuated air, fly to pieces.
8 A glass cylinder on a brass base, in which is a bladder, which contains a little
air held down by a weight, that is lifted up by the expansion of the air.
9 A glass, in which is enclosed a small tube to make a water-fountain in the
vacuum, by means of the expansion of the air enclosed in the small jar,
Desaguliers, ii, XL, fig. 16.
10 A larger glass, put together in the same way for a similar experiment, in
which a brass disk with a tap and cylinder is screwed on to the glass after the
air in the cylinder is evacuated, so that when the tap is opened a water-
fountain is made in the cylinder.