THE INDUSTRY OF ALL NATIONS.

of a pair which are moved by a system of wheel-work, and carry the paper fromits spool regularly forward. If the circuit is kept closed any appreciable time, thepaper is marked with a line corresponding to its motion. So soon as the currentis interrupted, the iron becomes demagnetized, and the spring attached to the ver-tical arm extending downwards from the axis, throws the armature up and disen-gages the point from the paper, which continues to move forward without furtherimpression. If a mere momentary impulse is given to the current, the point im-presses only a dot upon the paper. The current is broken and closed by the fin-ger key shown in the annexed figure. The operator presses upon the button, andthe point on the key is brought in contact with the corresponding point on thebase piece, and, as they both form parts of the circuit, the current is established,and a dot or line traced on the paper of the recording machine according to thetime of contact. On removing the finger, the spring attached to the key throwsit up, and breaks the circuit. The various combinations of dots, lines, and spaces

FINGEE KEY.

are arranged to represent letters or words. At first, Professor Morse proposed touse what he styled a port-rule, consisting of types of dots and marks set as theywere to be recorded, and traversing an instrument similar to the finger-key, andgiving to it a corresponding motion. This mechanical contrivance was soonsuperseded by the finger-key, with which the dexterous manipulation of a practisedoperator determines the lengths of the marks and spaces with sufficient accuracyfor practical purposes, and, although a single letter sometimes requires three orfour motions of the finger, transmits them at the rate of one hundred a minute.It is found that in passing through a long wire the electricity becomes dissipated,and reaches the distant terminus in too enfeebled a current to perform themechanical execution required. To obviate this, relay magnets are used, similarin principle to the recording instrument, but dispensing with the wheel-work, andusing the point to break and close the current of an additional set of batteries,which is thus brought into operation, and sends its power as far as may be prac-ticable to employ another battery; which, in its turn, may perform a similarduty, or merely work the recording machine at the terminus.

The imperfect drawing of the beautiful and ingenious machine invented byEoyal E. House, serves the purpose of a cursory glance at the instrument itself, bysuggesting the idea of an exceedingly complex arrangement of parts, whichrequire a careful examination to be understood. The cylinder shown on the leftcontains a helical coil of fine copper wire, well wrapped and insulated with silk,and forming the circuit with the telegraph wire. A brass tube, of about half aninch in diameter, is placed in the coil and has disposed inside its length eight shortiron cylinders. A small brass rodextending through the tube, andcarrying eight iron discs, is sus-

discs, and causes them to attract one another and draw the rod downward. Onthe cessation of the current, the rod is drawn up by the spring of the horizontalwire; and thus the closing and breaking of the circuit occasions a vibration ofthe brass rod and a small piston valve carried by it in the air-chamber in theupper part of the cylinder. This chamber is supplied with air from a pumpattached to the frame of the machine, through the vertical pipe; and the office ofthe valve is to alternately supply the two horizontal pipes connecting with theopposite ends of a cylinder situated under the upper plate of the instrument andcontaining a piston governing the motions of an escapement, in a manner similarto that by which the escapement of a clock is governed by its pendulum. Themotion of a type wheel, with the twenty-six letters of the alphabet and a periodand blank engraved upon its twenty-eight projections, is regulated by this escape-ment. The air governs the motion of the type wheel, and is in its turn regulatedby the electricity. The machines are built in pairs, comprising the above par-tially described recording instrument, and the composing instrument; each con-nected when in operation with its fellow at the other terminus. The composingmachine consists of a cylinder situated under the lettered keys and carrying atone end a brass wheel called the circuit wheel, with one end of the telegraphwire in contact with its side. Its periphery is cut with fourteen slots, and haspressing against it an end of the telegraph wire fashioned into a spring, so that asthe cylinder and wheel are revolved the circuit is broken or closed by the passageof the spring over a slot or projection. A detent on the lower side of each keycatches a pin in the cylinder and arrests its motion, and also that of the type-wheel in the recording instrument. How suppose the letter A to be opposite theslip of paper placed to receive the message to be transmitted, and the key markedA detaining the cylinder and its wheel, with the circuit closed by the conductingspring resting upon one of the projections. On putting the machine in motionand releasing the key, the current is broken by the spring passing over the slotin the circuit wheel corresponding to B, and the escapement adverted to in therecording instrument, allows the type wheel to revolve the space of one detentand present the letter B. The spring again closes the circuit with the next pro-jection on the circuit wheel, and the type wheel presents the next letter; andthese operations are repeated in rapid succession until the motion of the cylinder isarrested by pressing down one of the keys, and causing the type wheel to stop withits corresponding letter opposite the paper. When the type wheel of the record-ing machine is put in motion, a second peculiar escapement is detached and heldin abeyance until a cessation of the motion allows it to act, and, by means of aneccentric connected with it, draw the paper against the type wheel and producethe required impression. The motion of this escapement also releases the paperfrom the type after impressing it, and causes it to unroll from its spool and ad-vance a slight distance to present a blank for the next letter. A blackened stripof paper is also drawn against the type and causes the letter to be fairly printed,at the rate, in ordinary communications, of two hundred a minute. The motionsof the type wheel and its two escapements, and of the air pump and the circuitwheel, are all communicated through pulleys and bands from a treadle, workedby the foot of the operator. The letter A in the illustration is one of the letters

of an index wheel, correspondingto the type wheel, and enables theoperator to perceive at a glance

N.Lfvr. f.N.i

house’s electric printing telegraph.

pended from the horizontal wire seen stretched by set screws between the stand-ards above the cylinder.

The electricity traversing tne coil magnetises the little iron cylinders and

the condition of the instrument, and allows the letters to be read as they arepresented, if it should be desirable to remove the type wheel or paper and pre-vent the recording operation taking place.