IMPROVEMENTS IN ELECTRIC TELEGRAPH INSTRUMENTS AND RELAYS
Year: 1865

page_text: PROVISIONAL SPECIFICATION left by Isham Baggs at the Office of
the Commissioners of Patents, with his Petition, on the 20th June
1865.
I, ISHAM BAGGS, of Chancery Lane, in the County of Middlesex,
Electrical Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN ELECTRIC TELEGRAPH INSTRUMENTS AND RELAYS," to be as
follows:-
My Invention consists, first, in practically neutralising the effect of gravity
or magnetic attraction in telegraphic instruments and relays by means of
independent electric currents, which increase the delicacy or velocity of
action in the moving parts of the instrument. Supposing two distinct and
independent coils of wire wound round a horse-shoe of soft iron, the horse-
shoe is placed in a vertical position, with its poles downwards, coil No. 1 being:
wound round the upper part or bend of the horse-shoe, and coil No. 2 round.
the poles or limbs, according to the fashion of electro-magnets, as commonly
made. A small armature is placed directly under the poles at a distance
capable of adjustment; coil No. 1 is now made to communicate with a local
battery, also capable of adjustment so as to regulate the quantity of electricity.

page_text: circulating in such coil, and the consequent magnetism induced in the horse-
shoe. The quantity of induced magnetism is thus adjusted until the attraction
for the armature nearly balances the force of gravity, so that a very slight
addition to this attractive power will cause the armature to start up and be
drawn or attracted to the poles; coil No. 2 being connected with the line
wire, supplies this small additional force whenever telegraphic contact is made;
the motion of the armature, either of itself or in connection with a light index
or other appropriate machinery, appealing directly to the senses, or forming a
relay by striking against conductors appropriately disposed. To render the
attractive force of the local power more uniform through the range of the
armature, I sometimes use two distinct horse-shoes or electro-magnets lying at
right angles to each other or otherwise, the source of local attraction being
situated at a greater distance from its armature than the telegraphic.
Permanent magnets may be employed by approximation to give the requisite
degree of magnetic attraction to the horse-shoes or soft iron bars in place of a
local current of electricity; and small permanent magnets may be used in
place of iron armatures, but the above will serve to illustrate the principle of
action.
Second, my Invention consists in a telegraphic instrument or electro-meter
for ascertaining or indicating the direction and quantity of electric current.
This instrument consists of one or more powerful electro-magnets locally.
excited, and of a suspended electro-dynamic cylinder, helix wire, or electro-
magnet. When the cylinder, helix wire, or electro-magnet is brought into
action by a line wire, it is affected by the first-named magnet' or magnets,
according to known laws. These instruments may be used as relays.
Permanent magnets may be used in these instruments. in place of electric
currents, but the latter are preferable.
Third, in the employment of secondary currents for facilitating the release
or return of attracted, deflected, or movable bodies generally under the
influence of magnetism or electric currents. I surround a magnet partially
with a coil, through which the primary current.is conveyed, and I surround
another part of the magnet with an independent coil unconnected with any
battery; after, say, a needle has been deflected, I cut off the current through
the primary coil, when a reversed current will flow through the independent
coil, according to known laws, whereby the needle will be returned to its
normal position. I sometimes cause the like effect by making contact at
proper times or instants with a local battery.
And, lastly, in increasing the conducting power of wires and coils and the
magnetism of magnets by surrounding the apparatus with ice, freezing

page_text: mixtures, or other means of refrigeration; this is well effected by placing the
cooling materials in a thin hollow metal casing covering the apparatus,
and protected from external heat by non-conductors applied in any convenient
manner.