A NEW PEN- DULUM SPRING FOR TIMEKEEPERS, AND THE METHOD OF COMPENSATING THE EFFECT OF HEAT AND COLD OF THE SAME
Year: 1775

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
ARNOLD, of the Adelphi Buildings, in the Liberty of Westminster, in the
County of Middlesex, Watchmaker, send greeting.
WHEREAS His most Excellent Majesty King George the Third, by His
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Thirtieth day of December, in the sixteenth year of His reign,
did give and grant to me, the said John Arnold, His special licence, full
power, sole priviledge and authority, that I, the said John Arnold, my exe-
cutors, administrators, and assigns, should and lawfully might, during the term
of years therein expressed, make, use, exercise, and vend, throughout that part
of His Majesty's Kingdom of Great Britain called England, the Dominion of
Wales, and Town of Berwick-upon-Tweed, my Invention of "A NEW PEN-
DULUM SPRING FOR TIMEKEEPERS, AND THE METHOD OF COMPENSATING THE EFFECT
OF HEAT AND COLD OF THE SAME;" in which said recited Letters Pattent is con-
tained a proviso obliging me, the said John Arnold, by writing under my
hand and seal, to cause a particular of the nature of my said Invention, and
in what manner the same is to be performed, to be inrolled in His Majesty
High Court of Chancery within four calender months after the date of the
said recited Letters Patent, as in and by the said Letters Patent, and the
Statute in that behalf made, relation being thereunto respectively had, may
more at large appear.
NOW KNOW YE, that in compliance with the said proviso, and in pursu-
ance of the said Statute, I, the said John Arnold, do hereby declare that my
said Invention is composed, made, and performed in manner herein-after
mentioned, that is to say:-

page_text: By means of an helical or cylindrical spiral spring which is represented in
the annexed Figure 2, and which spring is made by winding a straight lamina
of steel round a cylinder, and on which it is hardened and tempered. In that
state it is fastened to the balance at C, as represented in the annexed Figure 1
vertically, and the other end is fastened to the cock. The compensation for
heat and cold is in the balance, and on the under side is affixed a spiral B, as
represented in Figure 1, which is composed of two metals, brass and steel, the
inner end of which is screwed to the collett of the verges; the other end hath
a small hole in it into which the pivott of lever D, in Figure 1, is inserted. A, A,
in Figure 1, are two segments of circles that are combined with the lever D,
by means of the arms F, F, in Figure 1, and made to approach the center of
the balance in hot weather, and to recede from it in cold, by the expansion or
contraction of the spiral B, by which means the resistance of the balance is
always equal to the tension of the spring.-N.B. The said Invention is
applicable to timekeepers for the pockets or otherwise.
In witness whereof, I have hereunto set my hand and seal, this Twenty-
seventh day of April, in the year of our Lord One thousand seven
hundred and seventy-six.
Sealed and delivered (being first duly
stampt) in the presence of
THO HANDLEY.
RICHD HATCH.
AND BE IT REMEMBERED, that on the Twenty-seventh day of April,
in the year of our Lord 1776, the aforesaid John Arnold came before our said
Lord the King in His Chancery, and acknowledged the Specification afore-
said, and all and every thing therein contained and specified, in form above
written. And also the Indenture aforesaid was stampt according to the tenor
of the Statute made in the sixth year of the reign of the late King and Queen
William and Mary of England, and so forth.
Inrolled the Twenty-seventh day of April, in the year of our Lord One
thousand seven hundred and seventy-six.