Edison, His Life and Inventions [322]
then connected to the nerves of the frog, BUT NO MOVEMENT OF ANY KIND COULD BE DETECTED UPON WORKING THE KEY, although the brilliancy and power of the spark were undiminished. The thought then occurred to Edison that the movement of the frog was due to mechanical vibrations from the vibrator (which gives probably two hundred and fifty vibrations per second), passing through the wires and irritating the sensitive nerves of the frog. Upon disconnecting the battery wires and holding a tuning-fork giving three hundred and twenty-six vibrations per second to the base of the sounder, the vibrations over the wire made the frog contract nearly every time.... The contraction of the frog's legs may with considerable safety be said to be caused by these mechanical vibrations being transmitted through the conducting wires."
Edison thought that the longitudinal vibrations caused by the sounder produced a more marked effect, and proceeded to try out his theory. The very next entry in the laboratory note-book bears the same date as the above (December 5, 1875), and is entitled "Longitudinal Vibrations," and reads as follows:
"We took a long iron wire one-sixteenth of an inch in diameter and rubbed it lengthways with a piece of leather with resin on for about three feet, backward and forward. About ten feet away we applied the wire to the back of the neck and it gives a horrible sensation, showing the vibrations conducted through the wire."
. . . . . . . . .
The following experiment illustrates notably the movement of the electric waves through free space:
"December 26, 1875. Etheric Force.--An experiment tried to-night gives a curious result. A is a vibrator, B, C, D, E are sheets of tin-foil hung on insulating stands. The sheets are about twelve by eight inches. B and C are twenty-six inches apart, C and D forty-eight inches and D and E twenty-six inches. B is connected to the vibrator and E to point in dark box, the other point to ground. We received sparks at intervals, although insulated by such space."
With the above our extracts must close, although we have given but a few of the interesting experiments tried at the time. It will be noticed, however, that these records show much progression in a little over a month. Just after the item last above extracted, the Edison shop became greatly rushed on telegraphic inventions, and not many months afterward came the removal to Menlo Park; hence the etheric-force investigations were side-tracked for other matters deemed to be more important at that time.
Doctor Beard in his previously mentioned treatise refers, on page 27, to the views of others who have repeated Edison's experiments and observed the phenomena, and in a foot-note says:
"Professor Houston, of Philadelphia, among others, has repeated some of these physical experiments, has adopted in full and after but a partial study of the subject, the hypothesis of rapidly reversed electricity as suggested in my letter to the Tribune of December 8th, and further claims priority of discovery, because he observed the spark of this when experimenting with a Ruhmkorff coil four years ago. To this claim, if it be seriously entertained, the obvious reply is that thousands of persons, probably, had seen this spark before it was DISCOVERED by Mr. Edison; it had been seen by Professor Nipher, who supposed, and still supposes, it is the spark of the extra current; it has been seen by my friend, Prof. J. E. Smith, who assumed, as he tells me, without examination, that it was inductive electricity breaking through bad insulation; it had been seen, as has been stated, by Mr. Edison many times before he thought it worthy of study, it was undoubtedly seen by Professor Houston, who, like so many others, failed to even suspect its meaning and thus missed an important discovery. The honor of a scientific discovery belongs, not to him who first sees a thing, but to him who first sees it with expert eyes; not to him even who drops an original suggestion, but to him who first makes, that suggestion fruitful of results. If to
Edison thought that the longitudinal vibrations caused by the sounder produced a more marked effect, and proceeded to try out his theory. The very next entry in the laboratory note-book bears the same date as the above (December 5, 1875), and is entitled "Longitudinal Vibrations," and reads as follows:
"We took a long iron wire one-sixteenth of an inch in diameter and rubbed it lengthways with a piece of leather with resin on for about three feet, backward and forward. About ten feet away we applied the wire to the back of the neck and it gives a horrible sensation, showing the vibrations conducted through the wire."
. . . . . . . . .
The following experiment illustrates notably the movement of the electric waves through free space:
"December 26, 1875. Etheric Force.--An experiment tried to-night gives a curious result. A is a vibrator, B, C, D, E are sheets of tin-foil hung on insulating stands. The sheets are about twelve by eight inches. B and C are twenty-six inches apart, C and D forty-eight inches and D and E twenty-six inches. B is connected to the vibrator and E to point in dark box, the other point to ground. We received sparks at intervals, although insulated by such space."
With the above our extracts must close, although we have given but a few of the interesting experiments tried at the time. It will be noticed, however, that these records show much progression in a little over a month. Just after the item last above extracted, the Edison shop became greatly rushed on telegraphic inventions, and not many months afterward came the removal to Menlo Park; hence the etheric-force investigations were side-tracked for other matters deemed to be more important at that time.
Doctor Beard in his previously mentioned treatise refers, on page 27, to the views of others who have repeated Edison's experiments and observed the phenomena, and in a foot-note says:
"Professor Houston, of Philadelphia, among others, has repeated some of these physical experiments, has adopted in full and after but a partial study of the subject, the hypothesis of rapidly reversed electricity as suggested in my letter to the Tribune of December 8th, and further claims priority of discovery, because he observed the spark of this when experimenting with a Ruhmkorff coil four years ago. To this claim, if it be seriously entertained, the obvious reply is that thousands of persons, probably, had seen this spark before it was DISCOVERED by Mr. Edison; it had been seen by Professor Nipher, who supposed, and still supposes, it is the spark of the extra current; it has been seen by my friend, Prof. J. E. Smith, who assumed, as he tells me, without examination, that it was inductive electricity breaking through bad insulation; it had been seen, as has been stated, by Mr. Edison many times before he thought it worthy of study, it was undoubtedly seen by Professor Houston, who, like so many others, failed to even suspect its meaning and thus missed an important discovery. The honor of a scientific discovery belongs, not to him who first sees a thing, but to him who first sees it with expert eyes; not to him even who drops an original suggestion, but to him who first makes, that suggestion fruitful of results. If to