wheels and thus take off all the power wanted. Not much less expensive was the plan to have a big tube from New York to Chicago, with Niagara Falls at the center, and with the Niagara turbines hitched to a monster air compressor, which should compress air under 250 pounds pressure to the square inch in the tube.

So far as actual electrical long-distance transmission from Niagara is concerned, it can only be said to be in the embryonic stage, for the sole reason that for nearly a year past the power company has been unable to get into Buffalo, and that not until last year was it able to arrive at acceptable conditions, satisfactory alike to itself and to the city. Work is now being pushed, and by June, 1897, power from the falls will, by contract with the city, be in regular delivery to the local consumption circuits at Buffalo, 22 miles away. But the question arises, and has been fiercely discussed, whether it will pay to send the current beyond Buffalo. Recent official investigations have shown that steam power in large bulk, under the most favorable conditions, costs to-day in Buf falo £10 per year per horsepower and upward. Evidently Niagara power, starting at £2 on the turbine shaft or say less than £4 on the line, has a good margin for effective competition with steam in Buffalo. As to the far-away places, the well-known engineers Prof. E. J. Houston and Mr. A. E. Kennelly have made a most careful estimate of the distance to which the energy of Niagara could be economically transmitted by electricity. Taking established conditions and prices. that are asked to day for apparatus, they have shown, to their own satisfaction at least, that even in Albany or anywhere else in the same radius 330 miles from the falls, the converted energy of the great cataract could be delivered cheaper than good steam engines on the spot could make steam power with coal at the normal price there of 12s. per ton.

What this enterprise at Niagara aims to do is not to monopolize the power but to distribute it, and it makes Niagara, more than it ever was before, common property. After all is said and done, very few people ever see the falls, and then only for a chance holiday once in a lifetime; but now the useful energy of the cataract is made cheaply and immediately available every day in the year to hundreds and thousands, even millions of people, in an endless variety of ways.

We must not omit from our survey the Erie Canal, in the revival and greater utilization of which as an important highway of commerce Niagara power is expected to play no mean part. In competition with the steam railway, canals have suffered greatly the last fifty years. In the United States, out of 4,468 miles of canal built at a cost of £40,000,000, about one-half has been abandoned and not much of the rest pays expenses. Yet canals have enormous carrying capacity, and a single boat will hold as much as twenty freight cars. The New York State authorities have agreed to conditions by which Niagara energy can be used to propel the canal boats at the rate of £4 per horsepower

per year.

Where steamboat haulage for 242 tons of freight now costs about 64d. a boat mile, it is estimated that electric haulage will cost not to exceed 54d., while with the energy from Niagara at only £4 per horsepower per year it will cost much less. Some two years ago the first attempt was made in the United States on the Erie Canal with the canal boat F. W. Hawley, when the trolley system was used with the motor on the boat as it is on an electric car, driving the propeller as if it were the car wheels. Another plan is that of hauling the boat from the towpath, and that is what is now being done with the electric system of Mr. Richard Lamb on the Erie Canal at Tonawanda, near Niagara. Imagine an elevator shaft working lengthwise instead of vertically. There is placed on poles a heavy fixed cable on which the motor truck rests, and a lighter traction cable is also strung that is taken up and paid out by a sheave as the motor propels itself along and pulls the canal boat to which it is attached. If the boats come from opposite directions they simply exchange motors, just as they might mules or locomotives, and go on without delay.

On its property at Niagara the power company has already begun the development of the new village called Echota, a pretty Indian name which signifies "place of refuge." I believe it is Mr. W. D. Howells, our American novelist, who in kindred spirit speaks of the "repose" of Niagara. It was laid out by Mr. John Bogart, formerly State engi neer, and is intended to embody all that is best in sanitation, lighting, and urban comfort. It does not need the eye of faith to see here the beginning of one of the busiest, cleanest, prettiest, and healthiest localities in the Union. The workingman whose factory is not poisoned by smoke and dust, whose home was designed by distinguished architects, whose streets and parks were laid out by celebrated engineers, and whose leisure is spent within sight and sound of lovely Niagara, has little cause for grumbling at his lot.

The American company has also preempted the great utilization of the Canadian share of Niagara's energy. The plan for this work proposes the erection of two power houses of a total ultimate capacity of 125,000 horsepower. Each power house is fed by its own canal and is therefore an independent unit. Owing to the better lay of the land, the tunnels carrying off the water discharged from the turbines on the Canadian side will have lengths respectively of only 300 and 800 feet, thus avoiding the extreme length and cost unavoidable on the American side. With both the Canadian and American plants fully developed, no less than 350,000 horsepower will be available. The stationary engines now in use in New York State represent only 500,000 horsepower. Yet the 350,000 horsepower are but one-twentieth of the 7,000,000 horsepower which Professor Unwin has estimated the falls to represent theoretically. If the 350,000 horsepower were estimated at £4 per year per horsepower, and should replace the same amount of steam power at £10, the annual saving for power in New York State alone would be more than £2,000,000 per year.

Let me, by way of conclusion, emphasize the truth that this splendid engineering work leaves all the genuine beauty of Niagara untouched. It may even help to conserve the scene as it exists to-day, for the terrific weight and rush of waters over the Horseshoe Fall is eating it away and breaking its cliff into a series of receding slopes and rapids; so that even a slight diminution of the whelming mass of wave will to that extent lessen disruption and decay. Be that so or not so, those of us who are lovers of engineering can now at Niagara gratify that taste in the unpretentious place where some of this vast energy is reclaimed for human use, and then as ever join with those who, not more than ourselves, love natural beauty, and find with them renewed pleasure and delight in the majestic, organ-toned, and eternal cataract.

EARTH-CRUST MOVEMENTS AND THEIR CAUSES.

By JOSEPH LE CONTE.

INTRODUCTION-SOURCES OF ENERGY.

Nearly all the processes of nature visible to us-well-nigh the whole drama of nature enacted here on the surface of the earth-derive their forces from the sun. Currents of air and water in their eternally recurring cycles are a circulation driven by the sun. Plants derive their forces directly, and those of animals indirectly through plants, from it. All our machinery, whether wind driven, or water driven, or steam driven, or electricity driven, and even all the phenomena of intellectual, moral, and social activity have still this same source. There is one, and but one, exception to this almost universal law, namely, that class of phenomena which geologists group under the general head of igneous agencies, comprising volcanoes, earthquakes, and more gradual movements of the earth's crust.

Thus, then, all geological agencies are primarily divided into two groups. In the one group came atmospheric, aqueous, and organic agencies, together with all other terrestrial phenomena which constitute the material of science; in the other group, igneous agencies and their phenomena alone. The forces in the one group are exterior; in the other, interior; in the one, sun derived; in the other, earth derived. The one forms, the other sculptures, the earth's features; the one roughhews, the other shapes. The general effect of the one is to increase the inequalities of the earth's surface, the other to decrease and finally to destroy them. The configuration of the earth's surface, the distribution of land and water-in a word, all that constitutes physical geography at any geological time-is determined by the state of balance between these two eternally antagonistic forces.

PHENOMENA TO BE STUDIED.

Now the phenomena of the first group, lying, as they do, on the sur face and subject to direct observation, are comparatively well under'Annual address by the president, Joseph Le Conte, read before the Geological Society of America, December 29, 1896. Printed in Science, Vol. V, No. 113, pp.

321-330.

stood as to their laws and their causes. While the causes of the phenomena of the second group, hidden forever from direct observation in the inaccessible depths of the earth's interior, are still very obscure; and yet partly on account of this very obscurity, but mainly on account of their fundamental importance, it is just these which are the most fascinating to the geologist. The former group, constituting, as it does, the terrestrial drama enacted by the sun, its interest is shared by geology equally with other departments of science, such as physics, chemistry, and biology. The phenomena of the second group are more distinctively the field of geology.

If we compare the earth with an organism then these interior forces constitute its life force, while the other group may be likened to the physical environments against which it eternally struggles, and the outcome of this struggle determines the course of the evolution of the whole. Now in biological science nearly the whole advance bas heretofore been by study of the external and more easily understood phenomena, thus clearing the ground and gathering material for attack on the interior fortress, and the next great advance must be through better knowledge of the vital forces themselves. The same is true of geology. Nearly all the progress has heretofore been by the study of the exterior phenomena, such as erosion, transportation, sedimentation, stratification, distribution of organic forms in space, and their succession in time, etc. Many of the laws of these phenomena have already been outlined, and progress to-day is mainly in filling in and completing this outline; but the next great step must be through a better knowledge of the interior forces. This is just what geological science is waiting for to-day. Now the first step in this direction is a clear statement of the problems to be solved. The object of this address is to contribute something, however small, to such clear statement.

EFFECTS OF INTERIOR FORCES.

As the interior of the earth is inaccessible to direct observation, we can reason concerning interior forces only by observation of their effects on the surface. Now these effects, as usually treated, are of three main kinds: (1) Volcanoes, including all eruptions of material from the interior; (2) earthquakes, including all sensible movements, great and small; (3) gradual small movements affecting large areas, imperceptible to the senses, but accumulating through indefinite time.

It is certain that of these three the last is by far the most fundamental and important, being, indeed, the cause of the other two. Volcanoes and earthquakes, although so striking and conspicuous, are probably but occasional accidents in the slow march of these grander movements. It is only of these last, therefore, that we shall now speak.

KINDS AND GRADES OF EARTH-CRUST MOVEMENTS.

The movements of the earth's crust determined by interior forces are of four orders of greatness: (1) Those greatest, most extensive, and