US777259A - Submarine telegraphy. - Google Patents

Description

UNITED STATES Patented December 13, 1904.

ISIDOR KITSEE, OF PHILADELPHIA, PENNSYLVANIA.

SUBMARINE TELEGRAPHY.

SPECIFICATION forming part of Letters Patent No. 777,259, dated December 13, 1904.

Application filed February 5, 1904. Serial No. 192,230. (No model.)

To all whom, it may concern.-

Be it known that I, IsIDoR KI'rsEE, of the city and county of Philadelphia, State of Pennsylvania, have invented certain new and useful Improvements in Submarine Telegraphy, of which the following is a specification.

My invention relates to an improvement in submarine telegraphy, and has more special reference to the telegraphic transmission of intelligence over submarine cables or other conductors having a high static capacity.

The peculiar conditions which are met with in the transmission of electricity through long submarine lines render it necessary to take one of two courses in transmitting intelligence over such lines:

First. To transmit impulses of one polarity and then to clear the line with an impulse of opposite polarity. This course was tried repeatedly, but was abandoned for the reason that in telegraphing with one pole the transmitting-key has to be closed to produce a dash at the receiving end for a longer time than if the symbol to be transmitted should denote only a dot, and it seemed impossible to so regulate automatic clearing in a manner so as to conform to the varying unit of time the transmitting-key is closed.

Second. To use in transmitting messages the so-called double key, whereby impulses of one polarity were transmitted to denote a dot and impulses of a second polarity were transmitted to denote a dash. This second course was finally adopted and is now in general use. With the aid of this double key, if the code to be transmitted consists alternately of dots and dashes, the ideal clearing of the line would be reached; but in reality the code never consists of alternating dots and dashes but, on the contrary, in nearly every word or syllable two or more dots or two or more dashes are grouped together, and impulses of one polarity have to be transmitted in succession without an opportunity being given to clear the line. This drawback is readily realized by persons versed in the art; but no eflicient arrangement to overcome this difficulty has been practiced, and it is the aim of my invention to employ a method of telegraphing whereby this disadvantage is overcome. As said above, the ideal mode of transmitting over such lines is to be enabled to send after an impulse of one polarity an impulse of the opposite polarity of the same strength and duration and to follow this mode of working through the whole message to be transmitted. To accomplish this object, I make use of the following arrangement: At the transmittingstation I may use the double key, a device which by the depression of one lever transmits an impulse of one polarity and by the depression of a second lever transmits an im pulse of opposite polarity; but instead of, as is practiced to-day, using one lever exclusively for dots and the second lever exclusively for dashes in my arrangement a dot may be transmitted by the depression of one or the other of the levers; so, also, the dash; but to distinguish the dot from the dash at the receivingstation I symbolize the dot by one impulse, either positive or negative, and I symbolize the dash by two impulses in quicksuccession, the first impulse of a polarity di'tl erent from the polarity of the second impulse, each preferably being of equal duration with a dot impulse, and in this arrangement it does not matter relatively whether the first impulse is the positive or the negative current, as long as the second impulse is opposite to the first and as long as the first current impulse is opposite to the last impulse of the code-sign immediately preceding; but the depression of one key or lever should always alternate with the depression of the second key or lever. In other words, when a dot is transmitted with the aid of the positive lever then the second dot must be transmitted with the aid of the negative lever, or if after the first dot a dash should follow, consisting of two dots in quick succession, then the first dot composing the dash should be transmitted as an impulse of negative polarity and the second dot composing the dash should be transmitted as an impulse of positive polarity.

It is obvious that my system is not limited to the use of a single current impulse to represent a dot and a double current impulse to represent a dash, for this may be reversed and the double current impulse employed to represent a dot, the single current impulse rep resenting a dash. I

From the foregoing it is clear that my arrangement embraces the following points: First, all impulses are of alike duration and intensity; second, after the positive impulse a negative impulse must always follow, or vice versa, thereby preventing the choking of the line and at the same time fulfilling the ofiice of clearing the same; third, the value of a dot is transmitted through a single depression of one key, the polarity of said key not entering into consideration; fourth, the value of a dash is transmitted through one depression of each of the two keys, no matter if the positive or negative key is depressed first.

An example will clearly illustrate this method. Let us suppose that the word good has to be transmitted in the American Morse alphabet. As transmitted to-day the following impulses will have to be sent over the line, (taking it for granted that the positive impulse denotes a dash and the negative impulse denotes a dot.) Two positive and one negative to denote the letter Gr, two negatives to denote the first 0, two negatives to denote the second 0, one positive and two negative to denote the D. In my method the arrangement of the impulses has to be as follows, (taking it for granted that the operator starts with the right-hand or positive key:) Positive and negative impulse in quick succession to denote the first dash, positive and negative impulse in quick succession to denote the second dash, and positive impulse to denote the dot of the letter Gr, negative impulse to denote the first dot and positive impulse to denote the second dot of the first letter 0, negative impulse to denote the first dot and positive impulse to denote the second dot of the second letter 0, negative impulse and positive impulse in quick succession to denote the dash, a negative impulse to denote the first dot and positive impulse to denote the second dot of the letter D. Translated into characters symbolizing the positive pole by the positive sign and the negative pole by the negative sign, the impulses to be transmitted in accordance with the Morse alphabet for the word selected are as follows:

Morse,

Word, G O O D Cable code, H

Improved code,

In this method of transmission the opposite current impulses in quick succession which denote a dash would be received at the receiving end as similar impulsesgbut owing to the time required to charge the conductor or cable the first impulse would not be received as one of the same intensity or force with which it was sent, but would be modified by the impulse iminediatelyfollowing, which also would be modified by the first. This when indicated upon a siphon-recorder would constitute a compound or reverse curve similar to that when two dots are transmitted in succession, but of considerably less amptitude. So, as indicated on asiphon-recorder, the word good would be indicated by a sinuous line having four successive reversals of low amptitude, then five reversals of greater amptitude, then two reversals of low amptitude, and, finally, two reversals of greater amptitude. The reversals constituting a single letter would be separated by lines substantially horizontal or slightly inclined.

From the above it will be seen that with the method as used to-day very often two impulses of one and the same polarity have to be transmitted successively over the cable, a fact considered of great disadvantage by persons versed in the art, because therefrom often results the choking of the cable, and therefore the necessity of slowing up the transmission, by my system these defects are entirely eliminated. The moving of the Zero is one of the results of this manner of transmitting. \Vith my new method such choking cannot take place, for the reason that the impulse following after the preceding impulse is always of opposite polarity, and therefore clears the line entirely and prevents the trailing, which is in every long-distance transmission the bugaboo of telegraphy.

In the art of telegraphy it is well known that a certain time must elapse between the end of the impulse representing one character and the beginning of the impulse of the next succeeding character, and this is technically called the time unit. Now in my code 1 preferably make use of the time unit just the same as in the common Morse system, with the exception that between the two impulses denoting one dash, only a half time unit is employed. The car (if a sounder or a like instrument is used) will soon become accustomed to this half unit of time and will readily distinguish between a dot consisting of one impulse and a dash consisting of two impulses in quick succession.

The successful carrying out of my method transmitting telegraphic or C2 ble messages does not depend upon the use of any special form or receiver, for any form which is deemed preferable may be used, including instruments of either the graphic or the phonetic types.

My method of transmitting telegraphic symbols differs from those heretofore employed and devised, for each successive impulse is opposite to the preceding and each one represents a symbol or symbol element. When a continuously alternating current has been heretofore used, certain impulses have been suppressed, reversed, or otherwise modified, but still without doing away with the objectionable feature of having successive impulses of the same sign follow each other. Also where it has been attempted to form each telegraphic symbol by impulses of opposite sign to represent symbol elements the objection of having two successive symbols terminate and begin with impulses of the same sign has not been overcome.

I am aware that it has been proposed to use only those letters which in the Morse code are composed of alternate dashes and dots andutilize the same in certain code-words having letters which begin and end alternately with dots and dashes. In such a code the words available as code-words are very limited, while there is no provision to cause the ending of one word to have an impulse of opposite sign from the beginning of the first letter of the next word. In my method of telegraphing the words available are unlimited, while the ending of one word and the beginning of the neXt succeeding word will invariably have opposite signs without regard to the words or letters transmitted. Furthermore, it is well known in the practical side of telegraphy that it is impractical to distinguish symbol elements by means of impulses of different po tentials, owing to the unreliable effect produced by the capacity of the cable or other conductor.

Having now described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. The method of telegraphically transmitting messages, comprising the impressing upon the line successive impulses of opposite polarity each successive impulse representing a telegraphic symbol or symbol element, one symbol being distinguished from another symbol by a difference in the time unit between two symbol elements.

2. The method of telegraphically transmitting messages which comprises the impressing upon the line successive impulses of opposite polarity and of substantially equal duration, each. successive impulse representing a telegraphic symbol or symbol element, one symbol being distinguished from another symbol by a difference in the time unit between two symbol elements.

3. The method of telegraphically transmitting messages which comprises the impressing upon the line successive impulses of opposite polarity each successive impulse representing a telegraphic symbol or symbol element, one symbol being distinguished from another symbol by a diflerence in the time unit between two symbol elements and by a decrease in the intensity of the impulses of said elements as received.

4. The method of telegraphically transmitting messages which comprises the impressing upon the line consecutive impulses to represent the characters composing a message, each successive impulse representing a symbol or symbol element and of equal duration and strength but of opposite polarity.

5. The method of telegraphically transmitting messages, which comprises the impressing upon the line an impulse to characterize a dot, and impressing upon the line two impulses in quick succession to characterize a dash, each successive impulse being of opposite polarity.

6. The method of telegraphically transmitting messages over submarine cables which consists in causing to be transmitted one im pulse to denote a dot, and causing to be transmitted two impulses in quick succession to denote a dash.

'7. In submarine telegraphy, the method of transmitting characters of the Morse alphabet, which consists in transmitting one im pulse of a polarity opposite to the polarity of the preceding impulse for the symbol denoting a dot and transmitting in quick succession two impulses for the symbol denoting a dash.

In testimony whereof I hereby sign my name, in the presence of two witnesses, this 26th day of January, A. D. 1904:.

ISIDOR KITSEE.

WVitnesses:

R. M. PorHAM, EDITH R. STILLEY.