IMPROVEMENTS IN TIMEKEEPERS
Year: 1850

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
Tosco PEPPE, of Great Marylebone Street, in the County of Middlesex, Civil
Engineer, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Twenty-eighth day of
February, One thousand eight hundred and fifty, in the thirteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said George Tosco Peppe, my exors, adñiors, and assigns, Her especial license,
full power,
sole privilege and authority, that I, the said George Tosco Peppe,
my exors, admors, and assigns, or such others as I, the said George Tosco
Peppe, my exors, adñiors, or assigns, should at any time agree with, and no
others, from time to time and at all times during the term of years
therein expressed, should and lawfully might make, use, exercise, and vend,
within England, Wales, and the Town of Berwick-upon-Tweed, my Invention
of "IMPROVEMENTS IN TIMEKEEPERS;" in which said Letters Patent is con-
tained a proviso that I, the said George Tosco Peppe, shall cause a particular
description of the nature of my said Invention, and in what manner the
same is to be performed, by an instrument in writing under my hand and seal,

page_text: to be inrolled in Her said Majesty's High Court of Chancery within six
calendar months next and immediately after the date of the said in part recited
Letters Patent, as in and by the same, reference being thereunto had, will
more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
George Tosco Peppe, do hereby declare that the nature of the said Invention,
and the manner in which it is to be performed, are fully described and ascer-
tained in and by the following statement thereof, reference being had to the
Drawing hereunto annexed, and to the figures and letters marked thereon,
that is to say:-
My Invention consists in so regulating the descent of a column of mercury
enclosed in a glass tube, as to indicate by its motion in the tube, equal portions
of time. The method of constructing the Invention is as follows:-I take a
clean glass tube (A, B, Figure 1) 3 feet long, or of any other convenient
length, and having an internal bore or diameter of between one eighth and
one sixteenth of an inch, the external diameter of the tube may be three
eighths of an inch, or of any other convenient thickness; and I mark the
following divisions upon it: C, equidistant from both extremities A and B;
D, equidistant from C and one of the extremities B; and E and F, each three
inches from D. By means of a blowpipe flame I fuse the parts marked E
and F, until the bore on internal diameter of each is slightly contracted. By
means of a covered wire I then push into these contractions two pieces of
porous wood, each three eighths of an inch in length, and made to fit so tightly
as to prevent mercury readily passing through the contractions E and F.
I then fuse D until the internal diameter is reduced to about the one two
thousand five hundredth of an inch; the exact amount of contraction
required is ascertained by the process hereafter described. I
pour into
F, B, a column of mercury about an inch in length, and place the tube in as
nearly a vertical position as possible, with the end A uppermost. The column
of mercury (supposed to be resting on F) will be held suspended in the
tube by the joint action of the atmospheric pressure and the capillary attraction
of the mercury and glass. Were the orifice D entirely closed, or the plugs of
wood at E and F impervious to air, the mercury would remain constantly
suspended in the same part of the tube; but the orifice D, though small, is
still open to the passage of air, and E and F, though not pervious to mercury,
are quite pervious to air; the weight of the column of mercury will gradually
draw air through E, D, and F, and the mercury will begin to fall with a speed
proportioned to the diameter of the orifice at D and the weight of mercury in
the tube. Should it be found that the mercury falls too rapidly, the orifice at

page_text: D is again subjected to the action of the blowpipe flame and again contracted
until the proper rate of descent is obtained. Should it be desired to make the
mercury descend more rapidly, by adding to the weight of mercury in the
tube, any increase of specd may be obtained. The tube is now bent on itself
at C, and the two extremities united so as to form a continuous internal tube,
as shewn by A, B, C, D, Figure II. At S a small tube is formed by drawing
out a portion of the glass while hot, so as to form a communication with the
interior of the tube A, B, C, D. L, M, is a cylinder of white glass or of
wood, about half an inch in diameter, and about. three inches shorter than
A, B, C, D; it is attached to the two limbs K, I, and G, H, by two pieces of
soft sheet brass or copper, as at K, L, G, and I, M, H, Figure II., and
a, b, c, d, e, f, in Figure III. The use of the cylinder L, M, is to serve as an
index or dial plate to indicate the spaces passed through by the descending
column of mercury; it is made to slip up and down in the limbs K, I, and
G, H. The plugs of wood in E and F serve as filters to prevent particles of
dust or of mercury obstructing the orifice D. To prevent the deposition of
oxidised films of mercury in the tube, I insert through the tube S a drop of
concentrated sulphuric acid or of purified oil, which lubricates the internal
surface of the tube and forms a fluid envelope to the mercury; for the same
purpose also I fill the tube with nitrogen or hydrogen gas, in place of
atmospheric air. The tube S is now filled by the blowpipe, so that all
communication between the interior of the tube and the external air is
completely cut off. By this means variations of temperature and atmospheric
pressure are prevented from exercising any influence on the motion of the
mercury in the tube. The graduation of the index is effected by suspending
the instrument from one end A, so that it may hang freely in a perpendicular
direction, and marking on the index, by reference to a standard chronometer,
the position of the mercury at stated intervals as it descends from A to C.
When the mercury has descended to the bottom of the index the instrument
is inverted, by suspending it from C, instead of A; by this means the mercury
will again be placed in the upper part of the tube, and will again begin to
descend by the force of gravity with the same speed as before, but indicating
the progress of the hours in a contrary direction on the index. To prevent
confusion in the use of these two indexes, I prefer putting one on the side R
of the cylinder L, Figure III., and the other on the side O, so that when the
instrument is inverted it is also necessary to turn the surface R into the
position formerly occupied by O. This instrument may be made to indicate
periods of time from our hour to twenty-four hours, without requiring to be
inverted; or by diminishing the size of the orifice D, and lessening the weight

page_text: of mercury suspended in the tube, it may be made to indicate the days of the
month or year, and will not require to be inverted during the whole of either
of these periods.
In order that the time at which the instrument requires to be inverted may
not be limited to a fixed period, the numeration is extended beyond the average
time of going to the extent of range required, as exhibited in Figure IV., where,
on the supposition that the instrument has to be inverted every twelve hours,
the numeration has been extended two hours so that the inversion may take
place at any period within those two hours, by simply sliding the index up or
down the tube until the mercury indicate the same hours or part of an hour
on the scale on the side R, as it did on the scale on the side (O).
What I claim as my Invention is the method of regulating the descent of a
column of mercury contained in a glass tube, by causing its rate of motion to
depend on the air beneath the mercury in the tube passing by a regulated
orifice to the portion of the tube above the mercury, and the application of
this regulated motion to indicate equal portions of time.
In witness whereof, I, the said George Tosco Peppe, have hereunto set
my hand and seal, this Twenty-seventh day of August, in the year of
our Lord One thousand eight hundred and fifty.
GEORGE TOSCO (L.s.) PEPPE.
AND BE IT REMEMBERED, that on the Twenty-seventh day of August,
in the year of our Lord 1850, the aforesaid George Tosco Peppe came before
our said Lady the Queen in Her Chancery, and acknowledged the Specification
aforesaid, and all and every thing therein contained and specified, in form
above written. And also the Specification aforesaid was stamped according
to the tenor of the Statute made for that purpose.