A NEW OR IMPROVED INSTRUMENT OR APPARATUS FOR MEASURING ANGLES AT BILLIARDS
Year: 1880

page_text: LETTERS PATENT to James Fisher Armistead, of Cobwall House, Blackburn,
in the County of Lancaster, Esquire, Justice of the Peace, for an Invention
of "A NEW OR IMPROVED INSTRUMENT OR APPARATUS FOR MEASURING
ANGLES AT BILLIARDS."
PROVISIONAL SPECIFICATION left by the said James Fisher Armistead
at the Office of the Commissioners of Patents on the 6th September 1880.
JAMES FISHER ARMISTEAD, of Cobwall House, Blackburn, in the County of
Lancaster, Esquire, Justice of the Peace. "A NEW OR IMPROVED INSTRUMENT
OR APPARATUS FOR MEASURING ANGLES AT BILLIARDS."
My Invention relates to an instrument or apparatus for measuring angles at
billiards, so as to enable the player to rightly direct his aim with reference to the
pocket or object ball, or any required point on the table.
The instrument is constructed in the following manner :—
A cylindrical block is provided, on the side of which block the number of degrees
are marked to the extent of a semi circle.
The block is provided, with 2 pointers, one fixed and the other moveable. The
movable pointer is attached to the block by means of a screw, by the act of turning
which in one direction the pointer may be loosened sufficiently to admit of its being
turned to any required angle, and when set it may be secured in its adjusted
position by the act of turning the screw in the opposite direction.
The head of the screw is made somewhat elevated, and is suitably shaped to
admit of its being used as a sight point to assist in detecting the straight line.
The movable pointer may thus be set to any angle in the whole circle, and will
point out the exact number of degrees of variation from a straight line accordingly
as it is set.
The said pointer is double ended, one end being longer than the other for the
convenience of taking angles. To the block is attached a card graduated in a
corresponding manner to the former, the movable pointer travelling over the card'
when turned.
In the movable pointer are two openings, one of which (near the centre) is
intended to enable the operator to see the centre of the object ball when it is
:

page_text: against the block, if it be required to ascertain particularly the direction of the
object ball, which always must lie in the direction of a line drawn through the
centre of both balls at the moment of contact. The other opening in the movable
pointer is to show the figures on the card when the angle required to be measured
is less than 90 degrees, and nearer to the operator, sometimes called a screw back
angle, in other words an acute angle.
The instrument is used in the following manner, viz. :-
The block (which is intended to represent the striker's ball at the moment of
contact with the object ball) is adjusted to the object ball with great exactness in
the position which it is the striker's intention that his own ball shall occupy at
the moment of contact. The degrees in front of the block are to assist in the
adjustment at the same time that the fixed pointer is set on the centre of the
striker's ball. These two points must be secured at the same time in order to
have the instrument correctly set. When the block is adjusted, the fixed pointer
is exactly set straight on the striker's ball at the same time that the point of
contact is adjusted. Then the movable pointer can be turned to the pocket, the
other ball, or to any point on the table required, and the card will shew the
exact number of degrees through the centre of the block, which is the same thing
_as_through the centre of the striker's ball, when it comes in contact with the
object ball. When the instrument-is-set-the-movable-pointer-always_shows_by
its short leg the number of degrees the other or long leg of the pointer must
-be-at-the-same.degree_of_deviation from the line of the striker's ball (or fixed
_pointer), before contact with the object ball. All angles begin with-and-from-the-
centre of the striker's ball, and the object-ball-or-ball-played upon always moves in
a straight line from the point of contact in the manner that would be represented
by a line passing through the centre of both balls at the moment of contact, so that
when the block is adjusted to the object ball, it really shows the direction the
object ball must take. With this instrument any angle can be set out and marked
with chalk ready for practice; thus the eye can be educated to know a particular
angle by being made aware of its real character or doviation.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Fisher Armistead in the Great Seal Patent Office on the 5th
March 1881.
JAMES FISHER ARMISTEAD, of Cobwall House, Blackburn, in the County of
Lancaster, Esquire, Justice of the Peace. "A NEW OR IMPROVED INSTRUMENT
OR APPARATUS FOR MEASURING ANGLES AT BILLIARDS,"
My said Invention relates to an instrument or apparatus for measuring angles at
billiards, so as to enable the player to rightly direct his aim with reference to the
pocket or object ball, or any required point on the table.
The instrument is constructed in the manner hereinafter described with reference
to the several Figures on the Sheet of Drawings hereunto annexed.
Figure 1 represents a perspective view of the instrument; Figure 2 is a plan;
Figure 3, a side elevation, and Figure 4, a vertical section of the same.
The same letters of reference indicato corresponding parts in all these Figures.
A is a block which is made in the form of a column of such height as to allow
the instrument to be worked over the cushions, or over another ball and of the same
diameter, and is intended to represent and will represent the striker's ball when it
is adjusted to the object ball.
This block is provided with a card B on its front portion marked in ten degree
divisions, commencing at zero and extending to, say, ninety degrees in opposite
directions, by the aid of which card the striker is enabled to adjust the block to
the object ball in the position which ho intends his own ball to occupy at the
moment of contact.
The block has a metallic base C to keep it on an upright and firm position, and
carries two pointers D, E, the one being fixed and the other moveable.
The fixed pointer D is let into the block and is fast. It is intended to represent
the line of the striker's ball. In fixing the instrument, this pointer is always to be
set in a straight line on the striker's ball from the centre of the block when the
block is adjusted to the object ball.
The moveable pointer E moves on a pivot F formed by a screw, which is scrowed
into the block. By the act of turning this screw in one direction, the pointer may
be loosened sufficiently to admit of its being turned to any required angle, and
when set, it may be secured in its adjusted position by the act of turning the screw
in the opposite direction.
The head of the screw is made somewhat elevated, and is suitably shaped to
admit of its being used as a sight point to assist in detecting the straight line.
The moveable pointer may thus be set to any angle in the whole circle, and with
the aid of an index card, hereinafter described, will point out the exact number of
degrees of deviation from the line of the striker's ball. The moveable pointer is
made double ended, one end e being longer than the other cad c¹ for the con-
venience of taking angles, the short end e' pointing out the number of degrees,
whilst the long end e points to the pocket or other object required.
To the block is attached a graduated index card G consisting of a scale g,
extending from zero to ninety degrees in opposite directions, and a scale g¹ marked in
ten degree divisions, and arranged to fit the front of the block. The zero point of
both scales coincides with the centre of the fixed pointer; the scale g₁ assists
in adjusting the block, and shews the card in front of the block to be properly
adjusted.
In the moveable pointer are two openings H, H³, one of which (H near the
centre) is intended to enable the operator to see the centre of the object ball when
it is against the block, if it be required to ascertain particularly the direction of
the object ball, which always must be in the direction of a line drawn through the
•

page_text: centre of both balls at the moment of contact. The other opening H' in the
moveable pointer is to shew the figures on the card when the angle required to
be measured is less than ninety degrees, and nearer to the operator, sometimes
called a screw back angle, in other words an acute angle.
The instrument is used in the following manner:-
The block is intended to represent the striker's ball at the moment of contact
with the object ball, and therefore must be adjusted to the object ball with the
greatness exactness in the position it is the striker's intention that his own ball
will occupy at the moment of contact. When the block is adjusted, the fixed
pointer must be exactly set straight on the striker's ball at the same time that the
point of contact is adjusted. Then the moveable pointer can be turned to the
pocket, the other ball, or to any point on the table required, and the card will shew
the exact number of degrees through the centre of the block, which is the same
thing as through the centre of the striker's ball when it comes in contact with the
object ball. All angles begin with and from the centre of the striker's ball, and
the object ball or ball played upon always moves in a straight lino from the point
of contact in the manner that would be represented by a line passing through the
centro of both balls at the moment of contact, so that when the block is adjusted
to the object ball, it really shows the direction the object ball must take. With
this instrument any angle can be set out, and marked with chalk ready for practice.
Thus the eye can be educated to know a particular angle, by being made aware-of
its-real-character_or_deviation. Thus assume that an angle of 35 degrees is required
to be set out; place the block (after having set the pointer at thirty five degrees) in or
near the centre of the table, let-the-fixed-pointer bo in the direction of the D or half
circle in baulk; next place the object ball touching thirty degrees on the block-at-the-
opposite side to the moveable pointer; now mark the place occupied by the object
with chalk, it it will be one inch and 3 from the 30° on the block; the striker can
arrange this angle for the moveable pointer to be dead on the pocket, top corner,
and mark the place for tho striker's ball indicated by the line of the fixed pointer,
say, somewhere in the half circle in baulk. The fixed pointer always is supposed
to and docs represent the line of the striker's ball before contact with the object
ball. The half ball angle is probably the most useful losing hazard at billiards;
this is 35° degrees deviation from the line of the striker's ball; it is used very much
in making the middle pockets from the D, also the top pockets from D, and in
many other positions also. It is therefore necessary that the player should have
his eye educated so as to know this angle in an instant. When the striker is
spotting for this angle in practice, and wants to know if he has got it correctly, the
instrument if at hand will test the angle as soon as it is adjusted, and by that
means the eye can be educated until its accuracy becomes a certainty. The striker
has not always a first class player to correct him; the instrument can be at hand
to correct any mistake. In executing the 35° degrees angle, the striker is supposed
to hit his own ball in the centre or just above the centre, otherwise the execution
is at fault, and not the spotting for the angle. In practise the instrument can bo
set at 35° degrees before it is placed on the table or set for any other angle, by first
slackening and then tightening the screw. The striker should always know
whereabouts he intends to hit the object ball; if he intends to hit it fine, the block
must be adjusted fine, at the same time the fixed pointer must be straight on the
striker's ball; if it is intended to hit half ball, adjust the block to half same time
as fixed pointer is pointing at striker's ball; if it is intended to hit full or nearly
full, adjust full or nearly full; the card in front of the block assists in all cases.
The moveable pointer can be set at any degree and secured by a turn of the screw
before the instrument is set on the table, or the moveable pointer can be fixed in its
place after it is set on the table; when adjusting the instrument near the centre of
the table, it is well for the operator to have a cue by him, as by gently tapping the
fixed pointer with the end of the cue, the adjustment is sometimes more easily
accomplished.
Having now described and particularly ascertained the nature of my said Invention,

page_text: and the manner in which the same is or may be used or carried into effect, I would
observe in conclusion that what I consider to be novel and original, and therefore
claim as the Invention secured to me by the hereinbefore in part recited Letters
Patent is,―
The new or improved instrument or apparatus for measuring angles at billiards,
substantially as hereinbefore described.
In witness whereof, I, the said James Fisher Armistead, have to this my
Specification set my hand and seal, this First day of March, One thousand
eight hundred and eighty one.
JAMES FISHER ARMISTEAD. (L.S.)
Signed, sealed, and delivered by the
said James Fisher Armistead in
the presence of
THOMAS MILBURN,
Clerk to Messrs. Houghton & Myres,
Solrs.,
Preston.