journeyed from Cañon City will be sent over the bridge, minus passengers, on grade, and all visitors therefore will walk across the chasm.

Once on the south side, the cars will roll back to Cañon City over another 4 per cent grade track, fifteen miles long, built in the sides of mountains and hills, and affording many new and novel views which are impossible from the ascending car. This part of the system will not be equipped with trolley wires, but will depend entirely on gravity for its momentum, and upon improved air-brakes for government.

Upward of $1,000,000 is expected to be spent in developing this new enterprise by the controlling corporation the Cañon City, Florence & Royal Gorge Interurban Railway Company.

The idea of bridging the chasm had occurred to but a very few people before

F. S. Granger, who is a promoter of original ideas and considerable constructive ability, undertook the task, to inaugurate which has required several years of experimenting with surveys. It is only within the past fifteen years that it has been deemed possible to overcome the engineering difficulties thought to lie in the path of building a railroad on either side of the Gorge. Previous to fifteen years ago, engineers would have declared any man a lunatic who suggested such a route as a possibility, even with unlimited capital; but in accordance with the modern advancement in civil engineering, broad-gauge railroad tracks are now constructed over mountain passes formerly considered wide enough only for burro trails, and bridges are built over chasms where geography illustrators twenty-five years ago declared "one false step would be fatal."

A

N earthquake survey of the United States and its possessions is one of the most recent enterprises of science.

Seismologists-the students of these phenomena are learning that Mother Earth is a much more tremulous creature than we have previously had reason to suppose. In fact it would almost appear that she is growing palsied as the chill of old age creeps over her.

If it is not straining imagination too much, it may be said that these seismologists are setting earthquake traps in various nooks and corners of our vast domain. These are among the most sensitive products of the instrument maker's fine art. They have a much more acute sense of touch than has been given to man. In fact, they would almost seem to have been endowed with brains, for they automatically write with pen and ink

all that they observe, and their records. are kept with a superhuman exactitude.

Seismographs Installed

The Government recently purchased in Germany six sets of the most improved apparatus of this category. These, known as "seismographs" or "seismoscopes," have been installed at Washington, D. C.; Cheltenham, Md.; Baldwin, Kan.; Vieques Island, Porto Rico; Honolulu, Hawaii; and Sitka, Alaska.

The Washington instruments are installed in a subterranean vault beneath the Weather Bureau, where they are in charge of C. F. Marvin, Professor of Meteorology in that institution. The other five sets have just been put in place in the new federal magnetic observatories at the other points named. They are being operated under the general direction of Dr. L. A. Bauer, Chief of the

Division of Terrestrial Magnetism, United States Coast and Geodetic Survey. Added to this chain of stations, are others at Manila, Philadelphia, and Baltimore. The first-named is in charge of Father Algue, a Jesuit scientist of the

clearing house, so to speak, for all of the American earthquake data; and, as soon as the co-operating stations shall have completed a sufficient continuous period of observation, he will issue statistics which no doubt will surprise us all.

Manila Observatory. The Quaker City's station is at Swarthmore College; and that of Baltimore, at Johns Hopkins University, where it is under the direction of Prof. H. F. Reid, the most eminent of American seismologists. Professor Reid's station is serving as the

Foreign stations, also, are co-operating in this work, particularly those at Toronto, Ont., and Victoria, B. C., under the meteorological establishment of Canada; and others at Mexico City; Cordoba, Argentina; and Arequipa, Peru. In fact, arrangements are being effected,

looking to the perfection of an earthquake survey of the world under the auspices of the International Seismological Association. This society has been organized for this special purpose under the leadership of Professor Gerland, Director of the Seismological Observatory at Strassburg, Germany. Japan will fall

trembling directly below it, it is standing still for the moment. It is spanned by an iron arch, whose base is a stone pier, penetrating the earth. All earth movements are directly communicated to the arch. Hence, when even the slightest tremor takes place, the arch moves therewith, but the weight below remains quiescent, as already said.

Attached to the stationary weight by a jeweled pivot, is a long, slender arm of aluminum, with a writing pen at its outer end. Upon the same foundation with the arch, and sharing all earth movements therewith, is a revolving wheel whose broad tire is a sheet of paper, against which the writing pen rests. The principle of the instrument, in a nutshell, is that each earthquake moves the paper against the pen, and records its tremors in zig-zags or curves. But, by a delicate adjustment, the aluminum arm exaggerates the earthquake tremor to a measurable degree.

into line with nearly 1,000 stations; Italy, with 15; England, with 3; Scotland, 2; India, 4; Canada, 2; Australia, 3; Russia, 3; and Spain, 2; also South Africa, Egypt, Ceylon, Java, Mauritius, New Zealand, Syria, Trinidad, Mexico, Peru, Argentina, and Germany, each 1. Thus Old Earth will have left but few surface areas where she may twitch undetected.

But, as to our own earthquake survey: -The six seismoscopes which we have installed are regarded as the most perfect of their class. The pattern is a modification of the recent invention of Professor Omori, secretary of the earthquake investigation committee of Japan. Japan is the great earthquake country, and has gone so far as to institute a chair in seismology at the University of Tokio.

How the Records are Made This new type of seismograph consists of a heavy weight, so suspended in front of a tall iron pedestal as to be always in neutral equilibrium and unaffected by any influence other than gravity. While the earth is quaking and

The wheel, with its paper tire, makes one revolution every hour. The recording pen commences its record on one edge, and, by aid of a thread on the wheel's axle, is made to trace gradually a perfect spiral over the endless band of paper, unless an earthquake interrupts. Thus the normal lines of the pen do not overlap. By means of an electromagnet attached to a specially made clock, a current is communicated every minute to another pen point, following the first and resting upon the same paper. The latter gives a hitch each time it receives an electric impulse, and thus checks off minutes along the spiral line traced by the first pen, which is "keeping tab" on Mother Earth's antics. A new paper is placed on the wheel at the same minute each day. It being known precisely when a new record is set, the exact time of a zig-zag earthquake line can be determined by counting the minute marks on the paper; and the exact

second of an earth tremor's beginning can be learned by applying a delicate scale dividing by sixty the space between two minute marks.

A pair of these instruments is necessary at each station. One, always pointed north and south, records earthquake vibrations moving east and west; the other, directed east and west, detects north and south movements. Each tremor makes its record on both instruments simultaneously. The zig-zag lines will be seen to differ materially when the paper strips are taken from the wheels and carefully compared with a scale. The exact direction of the earthquake wave, as well as its horizontal width, is thus measured to a nicety.

Delicacy of the Work

Only one out of several hundred or perhaps several thousand earthquakes recorded by these instruments, is perceptible to the public or reported by the newspapers. Typical of these earthquakes noticed month after month, was one caught by the Weather Bureau's seismograph just after its installation. On looking over the record sheets at the time of the daily change, Professor Marvin discovered a zig-zag perfectly inscribed and showing all the recognized characteristics of earthquake

out announcing the fact that his instruments had recorded the shock, Professor Marvin filed their records away and corresponded with other stations. He found that those of Baltimore, Victoria, and Toronto had recorded the shock at about the same time. By careful computation, he discovered that its first strong waves traveled from Victoria across the continent to Toronto in a fraction over eighteen minutes, and from Toronto to Washington in one and one-half minutes. The stronger waves traveled at the rate of nearly two miles per second.

That earthquakes will some day be systematically forecast, is a prophecy which may sound visionary, but one which has some scientific foundation. The Japanese seismologists now believe that they find indications of earthquakes' approaches upon the records of their magnetic instruments, preceding di

phenomena. The curve showed that there were preliminary tremors commencing at 9:29 A. M. and lasting five minutes. The main tremors then succeeded for 2 minutes 36 seconds. Terminal tremors lasted for 26 minutes 24 seconds. The total disturbance lasted 34 minutes. At the height of its activity, the earth beneath the instrument moved only a trifle more than a hundredth of an inch, from side to side. Small wonder, then, that the public was unaware of the shock.

But this tiny earthquake, undiscovered by press or public, traveled across the continent and was felt on the Pacific slope by a similar seismograph. With

rectly the effects shown by their seismographs. In other words, they have found what appear to be magnetic warnings of earthquakes. If their theory can be demonstrated, our Weather Bureau will doubtless profit by it; and we may expect, perchance, to see earthquake warnings displayed from mastheads above our public buildings, or to read at the top of the morning paper that Mother Earth will indulge in a shake-up at such or such an hour of the day. Pastors may then have time to gather in their flocks for public prayer, or urban residents may betake themselves to the open country, before the crash comes.