The American Electro Magnetic Telegraph / With the Reports of Congress, and a Description of All Telegraphs Known, Employing Electricity or Galvanism - Alfred Vail

Here we have the style of this kind of printing. By spelling the letters on the first line, then on the second, and so on, the words “Printing Telegraph” can be made out. Those letters which follow each other in the word, and also follow each other in the alphabet, are placed upon the same line, but when a letter occurs preceding the last, a new line must be taken, otherwise the word cannot be read. It will appear, that in this mode, sometimes two or three, or four letters, may be printed at one and the same instant, where they succeed each other in alphabetical order. This plan is extremely rapid for one instrument, but extremely slow for thirteen wires.

Supposing two such instruments are used upon a line of 40 miles, and suppose the wire to cost per mile, fifty dollars. The expense for wire alone would be $26,000. There are other expenses which we will omit in this, as well as those plans which will be described hereafter. Let it be assumed, in order to make equal comparison throughout, that the number of successive motions of the type lever, in these various plans about to be given, are 4 to a second. But as this instrument may make, with two or more of its levers, two or more impressions per minute, let it be 8 instead of 4 per second. It will then be capable of transmitting 480 letters per minute. With all this, there are many disadvantages, which will be developed as we proceed.

Under the same class, there is another plan, using the 26 types upon the ends of as many levers, each lever employing the electro magnet, and the line consisting of 13 wires. In this arrangement the types are made to strike in any succession required by the message, at the same point upon the paper, falling back and resuming their first position, after having printed their letter, in order to allow the next type to occupy the same point previously occupied by the other. The printing of this plan will appear on paper as ordinary printing. Thus, Printing Telegraph. If we suppose that 4 hammers, carrying type, can strike the same point in a second, and each resume their original position in succession, thus passing each other without collision, it may print at the rate of 240 letters per minute.[31] The instrument would be a complicated one and subject to derangement.

To the second class, belong all those which print in letters of an hieroglyphical character. The first plan is that employing one wire and one motion. Under this head, is that of Prof. Morse’s. He employs but one wire and one electro magnet for printing, which has but one motion. Suppose this to be capable of operating with the same speed as the preceding, viz. four motions per second. The telegraphic alphabet as adopted by Prof. Morse require for each letter the following number of motions of the type or pen lever, as lines require time in proportion to their length, they are so estimated: A 3, B 5, C 4, D 4, E 1, F 4, G 5, H 4, I 2, J 6, K 5, L 5, M 4, N 3, O 3, P 5, Q 5, R 4, S 3, T 2, U 4, V 5, W 5, X 5, Y 5, Z 5.

If we take the standard number of types for each letter constituting it printer’s case, considering Z as 2, we shall have A 85, B 16, C 30, D 44, E 120, F 25, G 17, H 64, I 80, J 4, K 8, L 40, M 30, N 80, O 80, P 17, Q 5, R 62, S 80, T 90, U 34, V 12, W 20, X 4, Y 20, Z 2. The whole number of letters are 1177. The number of motions required to transmit them would be 3420, to which add, one motion for the time required to space a single letter, and we have 4597 motions, made in printing 1177 letters which will make the average number of motions to each letter 3¹⁰⁶⁶⁄₁₁₇₇, nearly 4. Let it be 60 per minute. Expense for one wire of 40 miles, $2000.

Second plan, is that where two wires are used, two magnets, two type levers, and the telegraphic characters, such as are represented in table 1, page 30. The first three letters require three motions each; the next 16, require 2 each, and the last 7, require 3 each. Taking the 1177 letters, the motions required to transmit them in the characters of this alphabet, would be, 2195 + 1177 for spaces and would equal 3372, which divided by 1177, would give the average number of motions at 2¹⁰¹⁸⁄₁₁₇₇ for each letter, nearly three or 80 per minute. Cost of wire $4000.

Third plan, is that using three wires, three magnets, three type levers and the telegraphic characters represented in table second, page 30. The seven first would require one motion each, and the remainder two each. Taking 1177 letters, the motions required to transmit them, would be 1917 + 1177 for spaces, and would equal 3094 motions, which, divided by 1177, would give the average number of motions 2⁷⁴⁰⁄₁₁₇₇ for each letter, nearly 2⅔, or 85 letters per minute. Cost of wire $6000.

Fourth plan consists in using four wires, four electro magnets, four type levers, and the telegraphic characters of the third table. The first sixteen letters require the time of but one motion each; the remainder, two each. Using 1177 letters, the motions required to transmit them would be 1506 + 1177 for spaces, and would equal 2683, which divided by 1177, would give the average number of motions 2³²⁹⁄₁₁₇₇ for each letter, nearly 2⅓, or 103 letters per minute. Cost of wire $8000.

Fifth plan, is that of using five wires, five electro magnets, five type levers, and the telegraphic characters of the 4th table. The characters would require one motion each, equal to 1177 + 1177 for spaces, and would equal 2354, which, divided by 1177, would give the average number of motions, 2 for each letter, or 120 letters per minute. Cost of wire $10,000.