APRIL 28.] THE NEW ZEALAND GAZETTE. 1029

(2.) A cover, with slide, test-lamp for oil, or test-flame
arrangement for use with gas, and clockwork arrange-
ment for opening and closing the holes in the cover,
and for dipping the test-flame.

(3.) A water bath or heating vessel.

(4.) A tripod (with jacket), and spirit-lamp or gas arrange-
ment for heating the water bath.

(5.) A round bulb thermometer for testing the temperature
of the oil, with scale ranging from 55 degrees to
160 degrees.

(6.) A long bulb thermometer for testing the temperature
of the water, with scale ranging from 90 degrees to
220 degrees.

(7.) A mercurial or aneroid barometer.

The oil-cup is a cylindrical flat-bottomed vessel, 2 in. in
diameter, 2½ in. in height (internal), made of gun-metal or
brass (17 B.W.G.), and tinned or silvered inside. It is pro-
vided with a projecting rim, ½ in. wide, ⅜ in. from the top,
and 1⅞ in. from the bottom of the cup, on which it rests
when inserted in the water bath. A gauge is fixed on the
inside of the cup to regulate the height to which it is to be
filled with the sample under examination. The distance of
the point from the bottom of the cup is 1½ in. The cup is
provided with a close-fitting overlapping cover, made of
brass (22 B.W.G.), which carries the thermometer, the test-
lamp, or test-flame arrangement, and the adjuncts thereto.
The test-lamp, which has a spout, the mouth of which is
⅛ in. in diameter, or test-flame arrangement, is suspended
upon two supports by means of trunnions, which allow it
to be easily inclined to a particular angle and restored to its
original position. The socket in the cover, which is to hold
a round bulb thermometer for indicating the temperature
of the oil during the testing operation, is so adjusted that the
bulb of the latter is always inserted to distance of 1½ in.
below the centre of the lid.

The cover is provided with three holes—one in the centre
(0·2 square inch) and two smaller ones (each 0·06 square inch)
close to the sides. These are closed and opened by means of
a pivoted slide. When the slide is moved so as to uncover
the holes the suspended lamp, or test-flame arrangement,
is caught by a projection fixed on the slide, and tilted in such
a way as to bring the end of the spout or test-flame just below
the surface of the lid. As the slide moves back so as to
cover the holes the lamp returns to its original position.
Upon the cover, in front of and in a line with the nozzle of
the lamp, is fixed a white bead, the diameter of which repre-
sents the size of the test-flame to be used.

The water bath or heating vessel consists of two flat-
bottomed copper cylinders (24 B.W.G.)—an inner one of 3 in.
diameter and 2½ in. height, and an outer one of 5½ in. diameter
and 5⅝ in. height; they are soldered to a circular copper
plate (20 B.W.G.) perforated in the centre, which forms the
top of the bath, in such manner as to enclose the space between
the two cylinders, but leaving access to the inner cylinder.
The top of the bath projects both outwards and inwards
about ⅜ in.—that is, its diameter is about ¾ in. greater than
the body of bath, while the diameter of the circular opening
in the centre is about the same amount less than that of the
inner copper cylinder. To the inner projection of the top
is fastened, by six small screws, a flat ring of ebonite, the
screws being sunk below the surface of the ebonite to avoid
metallic contact between the bath and the oil-cup. The
exact distance between the sides and bottom of the bath
and the oil-cup is ½ in. The bath is therefore so constructed
that when the oil-cup is placed in position an air-space or
air-chamber intervenes between the two; consequently, in
applying the test to oils flashing below 115 degrees the heat
is transmitted gradually to the oil from the hot water, through
the air-space. The water bath is fitted with a socket, set
at a right angle, for receiving a long bulb thermometer, to
indicate the temperature of the water. It is also provided
with a funnel, an overflow pipe, and two handles.

The water bath rests upon a tripod stand, which is fitted
with a copper cylinder or jacket (24 B.W.G.) 6½ in. diameter,
so that the bath is surrounded by an enclosed air-space,
which retains and regulates the heat. One of the legs of
the stand serves as a support for a spirit-lamp, which is
attached to it by a small swing bracket. The distance of
the wickholder from the bottom of the bath is 1 in. The
clockwork arrangement by which, during the operation of
testing, the slide is withdrawn and the test-flame dipped into
the cup and raised again as the slide is replaced is provided
with a ratchet-key for setting it in action for each test, and
with a trigger for starting it each time that the test-flame is
applied. From the beginning to the end of the movement
of the slide the time taken is to be exactly 2 seconds.

N.B.—When gas is available it may be conveniently used
instead of the oil-lamp, and for this purpose a test-flame
arrangement for use with gas may be substituted.

II.-DIRECTIONS FOR PREPARING AND USING THE TEST
APPARATUS.

1. Preparing the Water Bath.

The water bath is filled by pouring water into the funnel
until it begins to flow out at the overflow-pipe. The tem-

perature of the water at the commencement of each test,
as indicated by the long bulb thermometer, is to be as
follows :—

(a.) 130 degrees, when a flashing-point at or about 73 degrees
is to be observed.

(b.) 160 degrees, when a flashing-point at or about 100
degrees is to be observed.

(c.) 180 degrees, when a flashing-point at or about 150
degrees is to be observed.

This is attained in the first instance by mixing hot and
cold water, either in the bath or in a vessel from which the
bath is filled, until the thermometer which is provided for
testing the temperature of the water gives the proper indica-
tion, or the water is heated in the bath by means of a spirit-
lamp or gas arrangement until the required temperature is
indicated.

2. Preparing the Test-lamp.

(a.) The test-lamp is fitted with a piece of cylindrical
wick of such thickness that it fills the wick-holder, but may
be readily moved to and fro for the purpose of adjusting the
size of the flame. In the body of the lamp, upon the wick
which is coiled within it, is placed a small tuft of cotton-
wool moistened with petroleum, any oil not absorbed by
the wool being removed. When the lamp has been lighted
the wick is adjusted by means of a pair of forceps or a pin
until the flame is of the size of the bead fixed on the cover of
the oil-cup.

Should a particular test occupy so long a time that the
flame begins to get smaller through the supply of the oil in
the lamp becoming exhausted, three or four drops of petro-
leum are allowed to fall upon the tuft of wool in the lamp
from a dropping-bottle or pipette provided for the purpose.
This can be safely done without interrupting the test.

(b.) When using gas for testing, the jet is to be lighted
and then adjusted by means of the tap controlled by means
of a screw pinch-cock or fine tap until the flame is the size
of the head fixed on the cover of the oil-cup.

III.-FILLING THE OIL-CUP.

Before the oil-cup is filled the lid is to be made ready by
being placed upon the cup—i.e., the round bulb thermometer
is to be inserted into the socket so that the projecting rim
of the collar with which it is fitted touches the edge of the
socket, and the test-lamp is to be placed in position. The
oil-cup is to be cooled when necessary to a temperature not
exceeding—

(a.) 60 degrees, when a flashing-point at or about 73
degrees is being observed;

(b.) 85 degrees, when a flashing-point at or about 100
degrees is being observed;

(c.) 135 degrees, when a flashing-point at or about 150
degrees is being observed;

by placing it bottom downwards in water at a suitable
temperature. The oil-cup is now to be rapidly wiped dry,
placed on a level surface in a good light, and the oil to be tested
is poured in without splashing until its surface is level with
the point of the gauge which is fitted in the cup. The lid is
then put on the cup at once and pressed down so that its
edge rests on the rim of the cup.

IV.-APPLICATION OF THE TEST.

1. The water bath, with its thermometer in position, is
   placed in some locality where it is not exposed to currents
   of air, and where the light is sufficiently subdued to admit
   of the size of the entire test-flame being compared with that
   of the bead on the cover. The cup is carefully lifted, without
   shaking it, and placed in the bath, the test-lamp is lighted,
   and the clockwork wound up by turning the key. The
   thermometer in the oil-cup is now watched, and the clock-
   work is set in motion by pressing the trigger when the tem-
   perature has reached—

(a.) 63 degrees, when a flashing-point at or about 73
degrees is being observed.

(b.) 90 degrees, when a flashing-point at or about 100
degrees is being observed.

(c.) 140 degrees, when a flashing-point at or about 150
degrees is being observed.

If no flash takes place the clockwork is at once rewound and
the trigger pressed at the next higher degree, and so on at
every degree rise of temperature until the flash occurs.

2. When a flashing-point at or about 115 degrees is being
   observed the air-chamber is to be filled to a depth of 1¼ in.
   with cold water before the oil-cup containing the oil to be
   tested is placed in position.

3. The temperature at which a flash occurs, if not within
   8 degrees of the temperature at which the testing was com-
   menced, is the observed flashing-point of the oil, and by
   correction of the observed flashing-point for atmospheric
   pressure, as hereinafter described, the true flashing-point is
   obtained.

4. If, however, the flash takes place at any temperature
   within 8 degrees of the temperature at which the testing
   was commenced, the test is to be rejected, and the whole
   operation of testing is to be repeated with a fresh portion of
   the sample, the testing, however, to begin at 10 degrees