The phonoscope (Nov 1896-Dec 1899)

12 THE PHONOSCOPE Graphs, 'IPbones anb 'Scopes The riultiphone La Nature gives a description of a multiphone, the invention of M. Dussand. This appliance is intended to augment the sounds of the telephone and Phonograph, as well as to apply to other uses. By the means of this instrument deaf persons have been enabled to hear the telephone and Phonograph. But, while this is possible, its greatest utility will be in enabling partially deaf persons to hear these instruments, and to multiply their sounds so that they can be used in auditoriums on public occasions, as well as the multiplying of all kinds of sounds, and especially in rendering audible sounds now beyond the capability of the human ear. The Spectrograph The spectrograph is an instrument for photographing the spectra of celestial objects — that is, the rainbowlike hands into which their light is spread out t>y the prisms of a spectroscope. Among the investigations ~which are conducted with this instrument is that of the movement of stars "in the line of sight," or, in other words, directly toward us or directly from us. The movement is revealed by a very slight displacement of the dark lines that cross these spectra, and so accurately are the observations and measurements now made that according to a recent statement of Professor J. E. Keeler, the director of the Lick observatory, the probable error of a single determination of velocity with the Mills spectrograph attached to the thirty-six inch telescope is for the best stars, only about one-quarter of a kilometre per second, or less than one-sixth of a mile. That is to say, with this instrument it can be told not merely whether a star is approaching or receding, but how many miles it moves a second within this small limit of uncertainty. During the last three or four years this spectrograph of the Lick observatory has been used by Professor W. W. Campbell, assisted by W. H. Wright, for observing systematically certain stars suspected of being variable in their rates of movement. The results of the observations have been published from time to time in the last year, and form one of the most interesting and important contributions that have recently been made to stellar astronomy. Down to the present time fifteen stars have been found which vary in their velocities in such a way as to indicate that they are circling in orbits, that they form parts of systems consisting of at least two bodies which revolved about each other, or, rather, about their common center of gravity, like the two balls of a dumbbell tossed into the air. One of the most interesting of these cases is the discovery, that Polaris or the North Star, is a triple system, the bright and visible star being attended by at least two dark companions, one of which forms with it a binary star, having a period of about four days, while these two bodies circle together around the third, in a period not yet determined, but which is probably several years in length. This discovery, made from a comparison of fifteen photographs of the spectrum of Polaris, taken between the 5th and 30th of last August, has since been confirmed, so far at least as regards the binary system, by similar photographs obtained by E. B. Frost at the Yerkes observatory. Another very interesting star on Professor Campbell's list is Capella, the brilliant star which may now be seen in the early evening in the northwest. A recent examination of six spectrum plates of Capella, taken with the Mills spectrograph in 1897, "leaves no doubt that this star is a spectroscopic binary." The plates show a variation in the velocity of the star, the movement of which is from us, between the limits of about thirty-three and two miles a second. The companion of Capella, about which this movement is taking place, appears to be a dark body, but there are indications of a third companion, which is luminous and which circles round Capella with a short period, not yet determined, so that this star also is probably, like Polaris, at least a triple system. It may be interesting to recall here that a few years ago the star Beta Aurigae, a star of the second magnitude in the right shoulder of Auriga (the Wagoner) — Capella is in his left shoulder — was discovered at the Harvard college observatory to be spectroscopically binary, both components being bright and the period of revolution being about four days. Another of the stars which have been found by Campbell to be variable in their velocity is Epsilon Ursae Minoris, a star of the fourth magnitude, the third star from Polaris in the handle of the Little Dipper. This star moves sometimes towards us, sometimes from us, the variation in its rate of travel being nearly thirtymiles a second. Another star in this region of the heavens, which varies in its velocity still more rapidly is Omega Draconis, a star of the fifth magnitude, situated about midway between Polaris and the "eyes" of the Dragon. Four plates of the spectrum of this star, taken between July 25, and August 29, this year, give different velocities, ranging between eleven miles a second from us and thirty-eight miles a second towards us. Still another very interesting star on the list is Beta Capricorni, of the second magnitude, the lower of a very conspicuous pair of stars which we may see on a September evening low in the south. In August, 1898, this star was found to be approaching at the rate of about three miles a second. Between the dates May 15, and September 26, 1899, a number of spectrograms of the star were taken, which indicate different velocities, ranging between about twenty-eight and twenty-one miles a second. As was before stated, the list of these discoveries now contains fifteen stars, those named above being selected as especially notable. Only in the case of Polaris has a period of evolution been ascertained, but "the observations for determining the orbits of these bodies are well up to date," says Professor Campbell, "and for several of them are practically completed." Some idea of the labor involved in the observations which have led to these results, to say nothing of that of making the measurements and "reductions," can be formed from the statement that 522 plates were taken with the Mills spectrograph in the last year. The companion of Sirius was discovered by Alvan Clark, Jr., in 1862, and more recently that of Procyon has probably been seen by Schaeberle, at the Lick observatory, so that these companion stars have been taken off the list of dark suns. Evidence of the existence in space of non-luminous bodies of considerable size is also furnished by the variable stars of the "Algol type," stars, which, after shining steadily for a few days, undergo, in the course of a few hours, a greater or less diminution of brilliancy. The suggestion was made long ago, in the case of Algol, that this star was attended by a dark companion, which, revolving round it and passing periodically between it and us, cut off a portion of its light, and a few years ago Vogel, by means of the spectroscope, used as Campbell now uses it, proved conclusively that such is the case. The Nethoscope A step in advance in the science of meteorology has been made at the Auditorium tower. A new instrument by means of which an entirely new precision in study of cloud forms and movements is possible has been placed. This new piece of apparatus is called the nethoscope. This little device enables exact observation of cloud movements, and it is hoped that after some time the weather men will be able to foretell from the action and conformation of the clouds swimming in the bright sky the weather that is to come. They think it not unlikely that long series of observations in many places in all weathers will give data that will connect certain cloud forms with coming thunder-storms or cold waves or drenching rains or cylones. Again, it is expected that after long observation the velocity of the clouds may enable the forecasters to predict the winds to come. However, all this is in the future. For the present the weather men can do no more than take observations with the nethoscope day and night and Sundays and send the carefully marked charts to Washington, where the mathematicians will compare states of the barometer with the cloud shapes and speeds. It has been found already that there is connection between cloud conformations and velocities within single isothermal zones. The nethoscope is simple, A circular mirror with black instead of silver background is fixed in a frame so that it can be accurately leveled. Rising upward from one edge of the black mirror is a steel wire that has a cross-arm, also of wire. The two look like a ship's mast with a yard across it. From the tip of the mast, to make the resemblance more complete, runs a thread of rigging that extends to the center of the black mirror and there vanishes through a hole. The instrument is used by getting a sight of the cloud in the black mirror. Then the mastlike wire is moved until the eye sights over its tip and just catches the edge of the cloud's reflection at the center of the mirror. The tiny thread is pulled taut from masthead to center and its angle from the plane of the mirror measured with a scale. Next a calculation is made and the angle of the cloud's altitude is secured. From this can be deduced the cloud's height from the ground. This done, the measurement of its size is simple, the observer having a scale cut into the polished face of the mirror. The velocityis measured on the same scale, which is on a diameter of the circle, by moving the scale into the line of the cloud's movement. Zhc (Srapbopbone Wion tbe Blue IRtbbon Highest honors were won by the Columbia Phonograph Company on account of its display at the National Export Exposition recently held in Philadelphia. The award consisted of the blue ribbon and silver medal, the greatest honors within the gift of the Exposition. The exhibit of Graphophones, records and talking-machine supplies at the company's booth was also highly complimented by the committee on awards, at whose request the Graphophone Grand, the giant-voiced talking-machine, was utilized during the last days of the Exposition in the music hall of the main building as a part of the musical attraction. The reproductions of this machine which represents the farthest advance in the talking-machine art, could be heard without effort in every part of the immense auditorium.