IMPROVEMENTS IN THE CONSTRUCTION AND ARRANGEMENT OF TIME- KEEPERS
Year: 1858

page_text: This Invention received Provisional Protection, but notice to proceed with the
application for Letters Patent was not given within the time prescribed
by the Act.)*
PROVISIONAL SPECIFICATION left by George Tosco Peppé and Louis
Goodman at the Office of the Commissioners of Patents, with their
Petition, on the 9th March 1858.
We, GEORGE TOsco PEPPE, of 68, Brittannia Terrace, City Road, in the
County of Middlesex, Engineer, and LOUIS GOODMAN, of 285, Oxford Street,
in the same County, Linendraper, do hereby declare the nature of our said
Invention for "IMPROVEMENTS IN THE CONSTRUCTION AND ARRANGEMENT OF TIME-
KEEPERS," to be as follows:-
This Invention relates to certain improvements upon and modifications of
certain Letters Patent granted to the said George Tosco Peppé on or about
the Twenty-eighth day of February, One thousand eight hundred and fifty,
the Specification of which describes an apparatus by which equal portions of:
time are indicated by the descent or motion of a column or body of mercury,
enclosed in a glass tube, and regulated by the passage of air through a small:
orifice or porous stopper.
According to one modification two straight glass tubes are used; the one
open at both ends and enclosed within the other, which is hermetically sealed
at each end, leaving a space between the external surface of the inner tube
and the internal surface of the outer tube. The bore of the inner tube is
considerably contracted near one end so as to leave a very fine aperture of, say,
2th of an inch. This tube contains a small quantity of mercury, which is
perfectly free to descend by its own gravity along the entire length of the
inner tube, as far as the contraction, which is protected from the mercury or

page_text: other foreign bodies by a plug of blotting paper or other suitable material on
each side of it, which material should be sufficiently porous to allow air to
pass through it, whilst at the same time it will prevent the mercury from
getting at the contracted part of the tube. A plug of a similar description is
fitted into the opposite end of the inner tube to prevent the escape of the
This double tube is
mercury therefrom when the apparatus is reversed.
fitted on to a wooden or other suitable index, which index has the desired
portions of time marked thereon in two columns, the one reading from the
top downwards, and the other from the bottom upwards. In using this
timekeeper the tubes are slid along the index until the top of the short
column of mercury corresponds to the division indicating the correct time.
The mercury will then slowly descend, each period of time being indicated
by the position of the level of the mercury as regards the divisions on
the scale. When the mercury has run down, the instrument is reversed
and adjusted, the reading being taken from the other column. As the
speed of the descent of the mercury depends on the freedom with which
the air contained in the tubes passes from the under side of the column to
the upper side, and also upon the weight of the column itself, it follows
that the apparatus may be easily regulated by increasing or diminishing
the contracted aperture, or by increasing or diminishing the weight of the
column; the divisions are of course; made to suit the instrument, and are
applied after the tubes are completed. The amount of the descent of the
mercury in any given time is accurately noted and marked on the scale, which
distance may afterwards be subdivided into any number of fractional parts
required; according to another form of apparatus the double columns of
divisions are dispensed with, one only being used. The mercury on arriving
at the bottom of the tube is run back to the top by temporarily reversing the
apparatus and opening a small valve to allow of the free entrance of air into the
tube during the descent of the mercury.. The aperture is then closed again,
and the apparatus is placed.upright as before. This form enables the apparatus
to be fitted on to an ornamental stand, so as to form an elegant drawing room
timekeeper. By another arrangement the double straight tubes are dispensed
with, and a single tube only is employed in the form of a ring or spiral, having
its two ends connected, and leaving a contracted throat as before described
This ring or spiral is mounted on a horizontal axis, and contains a smal
quantity of mercury in the lower portion of the circle, or in one of its con
volutions. A fine cord having a weight attached to one end is wound round
a pully on the axis or round the ring itself, and the weight should be equal to
the amount of mercury displaced by, the resistance of the air in the tube as i

page_text: passes through the contraction. The circular or spiral tube may be made of
gutta percha, porcelain, or any other material not liable to be acted upon by
mercury.
A disc divided into the required intervals of time is also fitted' to the
axis, and as it rotates the correct time is indicated by a stationary pointer.
The weight and cord always tend to turn the disc and ring or spiral, and as
the mercury remains at the lower portion of the ring or spiral, the contracted
throat will gradually approach the mercury on one side and recede from it
on the other. The air contained between the mercury and the approaching
throat will escape slowly through that contraction to the opposite side of the
mercury, and it is the freedom with which this air passes through the contracted
throat that regulates the speed of the apparatus. When the throat has
arrived at the mercury the apparatus must be readjusted or wound up by
turning it in the opposite direction, so as to bring the throat back to the
opposite side of the mercury. The indicator may be made adjustable for the
purpose of setting it to the correct time.
In place of making a contracted throat in the mercury tube, a slightly
porous stopper may be used in the various modifications herein-before described,
such stopper being just sufficiently porous to allow of the slow passage of
air through it; in order to lubricate the interior of the mercury tube, it is
proposed to employ glycerine in lieu of the concentrated sulphuric acid
described in the Specification of the Patent herein-before referred to, as this
latter substance has been found to act injuriously by producing oxidation of
the mercury.
By another modification of this circular form of apparatus the mercury is
dispensed with, and a flexible tube of vulcanised india-rubber or other flexible
air-tight material is employed, but still having a contracted throat or porous
stopper made or fitted therein at one portion. This ring is mounted on a
horizontal axis as before, and is supplied with the same arrangement of
divided disc, indicator or pointer, and cord and weight. A small pulley or
roller bears upon one side of the ring so as to contract or compress its sides
together, and confine the air between the compressed portion and the con-
tracted throat or porous stopper. As the ring revolves by the action of the
weight and cord the air will be forced slowly through the throat, the size of
which will of course regulate the speed of the apparatus.