Part 4

These type were set up in a cavity, made by putting two pieces of long rules of brass plate together, side by side, with a strip of half their width between them; so as to make the cavity sufficiently large to receive the type. This was denominated the _port rule_, and is represented in figure 16 by A A. Parts of the type are seen rising above the edge of the _rule_, and below it are seen the cogs, by which, with the wheel, V, the pinion, L, and the crank, O, the port rule, with its type, were carried along at an uniform rate in a groove of the frame, K, R, under the short lever, C, which has a tooth, or cam, at its extremity. J is a support, one on each side of the frame, for the axis of the lever, B and C, at its axis, I; _a_ and _i_ are two brass or copper mercury cups, fastened to the frame. These cups have the negative and positive wires soldered to them, N and P. D and H are the ends of _one_ copper wire, bent at right angles at that portion of it fastened to the lever, B. The ends of the copper wire are amalgamated, and so adjusted, that when the lever is raised at C, by the action of its cam, passing over the teeth of the type, the lever, B, is depressed, and the wires, D and H, dip into the mercury cups, and thus complete the connection. This plan worked well, but was too inconvenient and unwieldy.

The second method was upon the same principle, with a more compact arrangement. The type being put into a hopper and carried one by one upon the periphery of a wheel, the teeth acting upon a lever in the same manner as in the figure preceding. The wheel being horizontal.

The third plan differed only in one respect, instead of the types moving in a circle, they were made to move in a straight line. Figure 17 represents that instrument. The type were all made with small holes through their sides, so as to correspond with the teeth of the wheel, A, driven by clock work and weight. K is the side of the frame containing the clock work. B is the hopper containing the types, with their teeth outward. The hopper is inclined at an angle, so that the type may slide down as fast as one is carried through the cavity, _a_ and _b_. C is a brass block to keep the type upright, and sliding down with them. E and F are two small rollers, with springs (not shown) to sustain the type, after the wheel, A, has carried them beyond its reach. G is a lever for the same purpose as C in figure 16. D its support, through which its axis passes. I′ is the long lever, O, of the left side figure, to the end of which, is the bent wire in the mercury cups, H and S, and to which are soldered the wires, P and N. T is the spring to carry back the lever, O. F′ is one of the small rollers, and G′ the short lever. At R may be seen a part of one of the type passing; the tooth having the short lever upon its point, thereby connecting the circuit at the mercury cups, H and S, by the depression of the long lever, O. The hopper, B, may be of considerable length, and at a less angle. When a communication is to be sent, it is set up in type, and put in the hopper. The clock work is then put in motion, and the wheel, A, will carry them down one by one. In this manner, the cam on the end of the lever, G, will pass over all the teeth of the type, as in the plan shown by figure 16.

The fourth plan was by means of keys, one for each letter and numeral. By pressing upon any one of the keys, it wound up the clock work of the instrument. The key being instantly released, and returning gradually to its former position, produced the closing and breaking of the circuit required to write its character upon the register.

The fifth plan is in some respects similar to the last, but much more simple, and requiring less time in transmitting intelligence. Figure 18 exhibits a view of the keyed correspondent, with its clock work. A′ represents a top view of it, and B′ is a side or front view. 1 1 1 1, of both views, represent the long cylinders of sheet brass, covered with wood or some insulating substance, except at the black lines, which represent the form of the letters, made of brass, appearing at the surface of the cylinder and extending down and soldered to the interior brass cylinder. A cross section of the cylinder is seen at D′, of which the blank ring is the brass cylinder, and the blank openings to the outer circle the metallic forms of the letter J, and the shaded portion of the circle represents the insulating substance, covering the whole surface of the cylinder, except, where the letter-forms project from the interior. It is obvious that every letter and parts of each letter are in metallic connection with the brass cylinder. At each end of the cylinder is a brass head, with its metallic journal, and the journal or arbor turns upon its centre in a brass standard, 17, secured to the vertical frame. To this standard is soldered the copper wire, N, connected with the negative pole of the battery. There are together thirty-seven letters and numerals upon the cylinder, and made to correspond to the letters of the telegraphic alphabet. To each of these, there is a separate key, directly over the letter cylinder. Each key has its button, with its letter, A, B, C, D, &c., marked upon it, and beneath the button in a frame of brass, is a little friction roller. The key is a slip of thin brass, so as to give it the elasticity of a spring, and is secured at the thicker end by two screws to a brass plate, extending the whole length of the cylinder, so as to embrace the whole number of keys. This plate is also fastened to the vertical mahogany frame. At the right hand end of the brass plate is soldered a copper wire, leading to the positive pole of the battery, after having made its required circuit through the coils of the magnet, &c. It is clear, that if any one of the keys is pressed down upon any portion of a metallic letter, that the circuit is completed; the galvanic fluid will pass to the brass plate to which, P, wire is soldered; thence along the plate to the spring or key; then to the small friction roller beneath the button; then to that portion of any letter with which it is in contact; then to the interior brass cylinder, to the arbor; then to the brass standard, and along the negative wire, soldered to it, to the battery. We have now to explain in what manner, the cylinder is made to revolve, at the instant any particular key is pressed, so that the metallic form of the letter may pass at an uniform rate under the roller of the key; breaking and connecting the circuit so as to write at the register, with mechanical accuracy, the letter intended.

4 4 is the platform upon which the parts of the instrument are fastened. 3 3 is the vertical wooden back, or support, for the keys and brass standard, 17. 2 is the barrel of the clock work contained within the frames, 5 5. With the clock work, a fly is connected for regulating its motion, and a stop, a, for holding the fly, when the instrument is not in use; 6 is a very fine tooth wheel, on the end of the letter cylinder; 7 is also a fine tooth wheel, on a shaft driven by the clock train. In the front view is seen, at 9, another fine tooth wheel, suspended upon a lever, the end of which lever is seen at 8, figure 18, A′. 18 is a stop, in the standard, 17, to limit the return motion of the cylinder, which also has a pin at 18, at right angles with the former. 16 is a small weight, attached to a cord, and at its other end, is fastened to the cylinder at _b_. The relative position of the three fine tooth wheels, and the lever, 8, are better seen in a section of the instrument, figure 19. The same figures represent the same wheels as in the other views, A′ and B′. 7 is the wheel driven by the weight and train. 6 the wheel, on the end of the cylinder, to which motion is to be communicated, and 9 is the wheel, suspended upon the end of the lever, 8, of which 10 is its centre. 1 1, is the brass lettered cylinder. 11 and 13 the buttons of the two keys, one a little in advance of the other. 14 is the spring and the two friction rollers of the key, may be seen directly under the buttons. 15 is the stop pin. 16 the small weight and cord attached to the cylinder, to bring it back after each operation. 4 4 is the end view of the mahogany platform. The arrows show the direction which the wheels take, when the lever is pressed with the thumb of the left hand at 8, so as to bring wheel 9, up against 7 and 6, connecting the two, as shown by the dotted lines. Wheel, 7, communicating its motion to 9, and 9 to 6, which causes the metallic letters to pass under the rollers in the direction of the arrow. Now, in order to use the instrument, let it be supposed a letter is to be sent. The stop, _a_, figure 18, A′, is removed from the fly, and the clock work is set in motion by the large weight. Then the thumb of the left hand presses upon the _lever_, 8, at the same time, _key_, _R_, is pressed down by the finger of the right hand, so that the small roller comes in contact with the cylinder. At the instant the roller touches the cylinder, the letter begins to move under the small roller, making and breaking the circuit with mechanical accuracy. When the letter has passed under the small roller, the thumb is taken off the lever, 8, and the finger from the key, R. The cylinder is then detached from its gear wheel, 9, and the weight, 16, instantly carries it back to its former position, in readiness for the next letter. Then the _lever_, 8, and the _key_, _E_, are pressed down at the same instant for the next letter, and it is carried under the small roller in the same manner as the first, which, when finished, the wheel, 9, is suffered to fall, and the cylinder returns to its natural position again. The same manipulation is repeated for the remaining letters of the word.

In the following figure, 20, is represented the flat correspondent. It somewhat resembles the keyed correspondent, but without keys or clock work. A represents the arrangement of the letters, presenting a flat surface. Those portions in the figure, marked by black lines and dots, represent the letters which are made of brass. That portion which is blank, represents ivory or some hard insulating substance, surrounding the metal of the letters. As in the keyed correspondent, each letter and parts of each letter extend below the ivory and are soldered to a brass plate, the size of the whole figure, A. A sectional view of this is seen at 1 1, which is ivory, and 2 2, the brass plate below. The whole is fastened to a table, B. 5′ and 5′ is a brass plate, called the guide plate, with long openings, represented by the blanks, so that when the guide plate, 5′ 5′, is put over the form, A, each opening is directly over its appropriate letter, and is a little longer than the length of the letter. 4′ and 4′ is the wooden frame, to which the guide plate is secured. The ends of this frame are seen in the sectional figure at 4 4, and the guide plate at 5 5. The dark portions of which, represent the partitions, and the blanks the openings. It will be observed here that the plate, 5 5, resting upon the wooden frame 4 4, is completely insulated from the brass letter plate 1 1, and 2 2. The blank space between them showing the separation. It is, however, necessary that the guide plate should be connected with one pole of the battery, and the letter plate with the other pole. For this purpose a brass screw, F, passes up through the table, B, and through 4, into the guide plate 5 5. The head of the screw has a small hole through it, for passing in the end of the copper wire, G, from the battery, and a tightening screw below, by which a perfect connection is made. At D, is another screw, passing through the table, and into the letter plate, 2 2. To the head of this screw is also connected another copper wire, E, extending to one of the poles of the battery.

This instrument, when used, occupies the place of the key or correspondent, in the description heretofore given of the register. The circuit is now supposed to be complete, except, between the guide plate, 5 5, and the letter plate, 2 2. Now, if a metallic rod, or pencil, C, be taken, and the small end passed through one of the openings in the shield, above the letter, its point will rest upon the ivory; and if it be gently pressed laterally against the side of the opening of the guide plate, at the same time a gentle pressure is given to it upon the ivory, and then drawn in the direction of the arrow, 4′, it is obvious, that when the metallic point reaches, for instance, the short line of letter B, the circuit will be closed; and the fluid will pass from the battery along the wire to the screw, F, then to the guide plate, along the plate, to the rod, thence to the metallic short line of letter B, thence to the letter plate below, thence to the screw, from the screw to the wire, and thence to the battery. When the point has passed over the short metallic line, it reaches the ivory, and the circuit is broken, then, when it comes upon the first metallic dot, it is again completed, and in the same manner the circuit will be completed and broken, until the point has passed over the whole of the letter. The use of this instrument requires great uniformity of time or speed in drawing the point over the letter form. The steel point of a common ever-pointed pencil is frequently used in place of the pointed rod, C.

The seventh plan is that heretofore explained as being now in use, of which there are several varieties. This mode of writing requires that the operator should be perfectly familiar with the alphabet, as he is obliged to spell the word, and measure the time, required by the various parts of each character making the letter. It might seem difficult, yet experience has proved it to be superior to every other method yet devised. By this method, intelligence is transmitted faster than it can be written down by reporters; and after a little practice, with so perfect a formation of the characters, that mechanical accuracy can alone be compared to it. As this is the simplest in its construction, it will doubtless supercede all the others. We will now give its simplest form.

THE LEVER KEY.

This, as we have said, is the most simple form of the key, or correspondent. It is a modification of that shown at figure 11. The following figure, 21, represents a key, where the lever is taken advantage of to make a more perfect connection, with less application of power. A key of the above form has been used during the past winter for reporting the proceedings of Congress, and has been found to operate with ease, with certainty, and with great rapidity. A A is the block or table to which the parts are secured. E represents the anvil block. J the anvil, screwed into the block, both of brass. B is another block, for the stop anvil, K, and the standard for the axis of the lever C. L is the hammer, and is screwed into the lever, projecting downward at V, almost in contact with the anvil, J. R is another screw of the same kind, but in contact with the anvil, K, when the lever C is not pressed upon. Under the head of each of these two screws, are tightening screws, which permanently secure the two hammers, to any adjusted position required for the easy manipulation of the lever, C. D is a spring which sustains the arm of the key up, preventing the hammer, L, from making contact with the anvil, J, when not in use. G is a screw connecting with the brass block, B, and F a screw connecting with the block, E. To these screws the two wires, I and H, of the battery are connected. Now, in order to put it in operation, it is necessary to bring the hammer, V, in contact with the anvil, J, for so long a time, and at such regular intervals as are required by the particular letters of the communication. When the key is pressed down, the fluid passes from the battery to the wire, H, then to the screw, G, then to the block, B, then to the lever, C, at the axis, S, then to its metallic anvil, J, then to its screw, F, then to the wire, I, and so to the battery.

_The circuit of the Electro Magnet, closed and broken by the movement of the lever itself, acted upon by the Electro Magnet. Showing the rapidity with which it is possible to close and break the circuit._

In order to give some idea of the rapidity with which the circuit may be closed and broken, and answered by the motion of the lever, a figure, 22, is here introduced to explain its construction and arrangement. The platform is shown at T, and the upright at S, to which the coils of the electro magnet, A, are secured by a bolt with its thumb-nut, E. D a projecting prong of the soft iron, and C the armature attached to the metallic lever, B, which has its axis or centre of motion at K, in the same manner as the electro magnet of the register; R being the standard through which the screws pass. O is the steel spring secured to R, by a plate, U, upon it, and the screw, N. L and M are adjusting screws, for the purpose of confining the motion of the lever, B, within a certain limit. P is a wire with an eye at the top, through which the end of the steel spring passes, with a hook at the other end, passing through the lever. The wire, Q, from one of the coils is connected with the plate, U, at the top of the standard, R. As the standard, R, is of brass, the plate U, the axis of the lever of steel, and the lever, B, of brass, all of them being metals, and conductors of the galvanic fluid, they are made in this arrangement to serve as conductors. I is the wire proceeding from the other coil, and is extended to one pole of the battery. The wire, H, coming from the other pole, is soldered to the metallic spring, J, which is secured to the upright, S, by means of the adjusting thumb screws, F and G. This spring is extended to J, where it is in contact with the lever, B. We have now a complete circuit. Commencing at I, which is connected with one pole of the battery, from thence it goes to the first coil; then to the second; then by Q to U, the plate; then to the standard, R; then to the steel screw, K; then to the steel axis; and then to the lever to the point, J; where it takes the spring to H, the wire running to the mercury cup of the other pole of the battery.

The battery being now in action, the fluid flies its circuit; D becomes a powerful magnet, attracting C to it, which draws the lever down in the direction of the arrow, X. But since B and J are a part of the circuit at V, and since, by the downward motion at X, and the upward motion at V, the circuit is broken at J, the consequence is, that the current must cease to pass, and D can no longer be a magnet. Hence the lever at V returns, coming again in contact with J. Instantly the fluid again passes and the lever at V separates from J. Again the fluid ceases to pass, and the lever again returns. By this arrangement, then, the lever breaks and closes the circuit, and it does it in the best possible manner to show how rapidly the magnet can be made and unmade. When its parts are well adjusted, its vibrations are so quick that no part of the lever is distinctly seen. It appears bounded in size by the limits of its movement up and down, and the motion is so rapid as to produce a humming noise, sometimes varying the notes to a sharp key. In this way it will continue to operate so long as the battery is applied. We infer from this, the almost inconceivable rapidity, with which it is possible to manipulate at the key of the register in sending intelligence, far surpassing that of the most expert operator. This arrangement of the electrome, was devised by Mr. Vail in the summer of 1843.[8]

[8] See Silliman’s Journal, vol. 35, 1839, pages 258-267.

CONDUCTING POWER AND GALVANIC ACTION OF THE EARTH.

After the close of the session of Congress in the spring, 1844, a series of experiments were commenced by the request of Prof. Morse, under the direction of Mr. Vail, for the purpose of ascertaining what amount of battery was absolutely required for the practical operation of the telegraph. From the first commencement of its operations to the close of the session, so anxious were the public to witness its almost magic performances, that time could not be taken to put it in a state to test either the size of the battery required, or bring into use all the machinery of the register. On that account, but _one wire_ was used during that period for transmitting and receiving intelligence, and the capabilities of the instrument were shown to some disadvantage; requiring the constant attendance of those having charge of the two termini.

This first experiment made was to ascertain the number of cups absolutely required for operating the telegraph. Eighty cups had been the number in use. Upon experiment, it was found, that two cups would operate the telegraph from Washington to Baltimore. This success was more than had been anticipated and urged on further experiments, which eventually proved that the earth itself furnished sufficient galvanic power to operate the electro magnet without the aid of a battery. In the first experiment, a copper plate was buried in the ground, and about three hundred yards from it, a zinc plate was also buried in the ground. To each of these plates a wire was soldered, and the ends brought into the telegraph office, and properly connected with the key and electro magnet of the register. The battery not being in connection. Upon manipulating at the key, it was found that the electro magnet was operated upon and the pen of the register recorded. This led to another experiment upon a more magnificent scale, and nothing less than that of using the copper plate at Washington, and the zinc plate at Baltimore, with the single wire, connecting those distant points, and the battery thrown out. Here, too, success followed the experiment, though with diminished effect. By the application of a more delicate apparatus the _Electro Magnet_[9] was operated upon, and the pen of the _registering instrument recorded_ its success. From these experiments, the fact appears conclusive, that the ground can, through the agency of metallic plates, constantly generate the galvanic fluid.

[9] Franklin appears to have been the first, or among the first, who used the ground as part of a conducting circuit in the performance of electrical experiments. Steinheil it appears was the first to use the ground as a conductor for magneto electricity. Bain, in 1840, was the first to use the ground as a source of electricity in conjunction with its conducting power, as a circuit. Prof. Morse, has since the establishment of the telegraphic line, used the ground as half the line, with perfect success, employing the battery; and Mr. Vail, in an experiment in 1844, succeeded in operating the electro magnet, with its armature attached to a lever, without any battery.

_Six Independent Circuits, with six wires, each wire making an independent line of communication._