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Cape Town and the intermediate points; and there is no doubt that the transmission of power to the nearest city would enable much of it to be used. Whether electrical energy could be effectively delivered to the gold fields of the Transvaal is a matter for discussion; but there is little doubt that the great source of power existing at the Falls of the Zambesi will ultimately play an important part in the industrial development of the African continent.
Notice has already been taken of the successful completion of the great masonry arch bridge at Luxembourg, this fine structure being especially notable for the great span of the arch, 84.65 metres, or nearly 278 feet. There is another feature, however, in this structure which is attracting attention as a guide to future masonry arches. Instead of being a solid arch of masonry the full width of the desired roadway, the Luxembourg arch consists of two separate arch rings placed side by side, with a considerable space between, the flooring extending above across both arches. This method possesses several advantages. The two arch rings can be separated by a distance equal at least to their thickness, giving a corresponding saving in the amount of masonry. Again, the cost of the expensive wooden centring necessary to support the arch during construction is materially reduced; since one arch ring is built first and the centring then shifted laterally to the line of the second arch, so that one centring of less than half the width of the completed bridge serves the purpose. In a masonry arch as now built, the proportion of dead to live load is so great that it is evident on inspection that the material is not used in the most efficient manner. The new method adds greatly to the efficiency of the material, and at the same time considerably reduces the labor and cost of the completed structure. This system, which has been so successfully used at Luxembourg, is now under consideration for the new bridge to be built across the Garonne at Toulouse, and its extended use is probable.
With the increasing attention which is being given to the development of internal waterways and canals, the improvements in methods of overcoming differences in level appear. The old method, as exemplified in the canal lock, is known to every one, and for many places it will doubtless long continue to be used. It has many defects, however, which are plainly evident. The difference in level which can be overcome by a single lock is limited to a few feet, and for greater elevations a succession of locks must be employed, this necessitating a large first
cost and involving great delays in operation. The waste of water involved in the continual operation of lock chambers must also be considered, and in some localities at certain seasons this is a matter of importance.
For these reasons other forms of lifts have been designed, the most satisfactory being made with tanks large enough to receive the canalboats together with sufficient water to float them, the tank being supported upon a hydraulic ram or plunger, by which it can be raised or lowered. By arranging two such tanks side by side and providing a communication between the cylinders in which the supporting rams work, the two loads balance each other, and the only power required for operation is that necessary to overcome inertia and frictional resistances. Such canal lifts have been used at Anderton, in England; at Les Fontinettes, in France; at La Louvière, in Belgium; and, with some modifications, at Henrichenberg, in Germany, with lifts of fifty to sixty feet. Recently an important lift of this sort has been completed on the line of the Trent Canal, at Peterborough, Ontario, and its operation has been most successful. The height to be overcome is, in this case, sixty-five feet, and the canal-boats are lifted through this distance in about three minutes a great gain in time and capacity over the old system of lock chambers.
An interesting detail of these canal lift locks appears in the method employed to make the necessary water-tight joint in the end of the tanks in which the boats are carried. The gates close upon packing made of rubber tubing. After being made secure, the tubing is inflated by an internal air pressure of ten pounds per square inch, this making an entirely water-tight joint and one as readily released as made.
By suitable care in the management of such a canal lift system, boats travelling in opposite directions may be passed through simultaneously, with corresponding gain in time and capacity.
With the completion of the Pacific Cable the electric circuit of the globe is complete, and, in consequence, some interesting and important investigations have been made possible. Thus the determination of the longitude of Manila, already effected telegraphically eastward from Greenwich by way of Madras and Vladivostok, has now been made westward, via San Francisco and Honolulu. The mean of the two eastward determinations gave the longitude of the dome of the cathedral at Manila as 8 hours, 3 minutes, 52.468 seconds, East, while the westward determination, involving the exchange of signals over 8,000 miles
of submarine cable, gave a value of 8 hours, 3 minutes, 52.425 seconds -a difference of only 0.043 second. This corresponds to a difference in distance of about sixty feet, and confirms the previous determinations in a very interesting manner. The telegraphic determination of the longitude of Midway Island shows a difference of more than a mile from its position as determined by previous chronometer measurements, this indicating the difference in precision between the two methods.
The extension of the telegraph system of the United States Signal Corps to Alaska gives some very convincing figures as to the extent of that territory, as well as concerning the work which is being done to aid in its development. At the present time the submarine cables used in the Alaskan system together make 2,079 miles, sufficient to reach from Newfoundland to Ireland, while there are 1,439 miles of land telegraph lines, or enough to extend from Washington to Texas. The wireless communication to Cape Nome has maintained satisfactory connection, and it is stated in the recent report of the chief signal officer that 5,000 words were exchanged one afternoon between Safety Harbor and St. Michael.
In connection with the operation of the Pacific cable, it has been proposed to send out time signals of the new year around the world. The signal was to be sent out from the Naval Observatory at Washington at midnight on December 31, and at one, two, and three o'clock A.M. succeeding, giving the standard time of the 75th meridian to all the other standard time belts.
One of the most important events in the application of electric power to traction purposes took place in the middle of November, in the form of public trials of an electric locomotive of the new high-speed type built for the service of the New York Central Railroad. The conversion of the terminal service in New York City from steam to electric traction has been a result of the late disaster in the tunnel, through which all the trains of the New York Central and the New York, New Haven and Hartford railroads must pass. The tunnel, originally constructed for much lighter duty than is now possible, is so frequently obscured by smoke and steam that it has become evident that the only way to secure safety is to use electric traction, and thus remove the causes of the difficulty. Electric locomotives are to be used to haul the trains from the Grand Central Station to points twenty to thirty miles out of New York, from which places the traction will be conducted by steam.
The electric locomotives, of which the one recently tested is an
example, are provided with four driven axles and two pony trucks, the motors being mounted directly on the axles without the interposition of gearing. Each motor is of 550 horse-power, or a total of 2,200 horsepower, at normal load, with a capacity for considerable overload for a short time, making the machine more powerful than any steam locomotive in existence. All the details appear to be well worked out. The public trials of the locomotive were most successful, speeds of 63 miles per hour being attained with an eight-car train weighing 431 tons, and 72 miles per hour with a four-car train weighing 265 tons. The current is taken from a third rail for the open country, but connections for overhead trolley are also provided for use in the yards and terminals.
These trials have demonstrated the capabilities of the design for the purposes intended, and doubtless the completion of a number of the machines will follow. They have demonstrated more than the mere success of a certain type of machine, since they have shown beyond possibility of contradiction that it is entirely possible for the terminal traction service of trunk-line railroads to be conducted without the use of the travelling power-house known as the steam locomotive. The use of steam locomotives for general main-line service will doubtless long continue, but there is no good reason to be urged for their admission within the suburban limits of any large city. The introduction of the electric locomotive may be the beginning of the abolition from within city limits of all machinery emitting smoke, steam, and gas, and for this reason especially these electric locomotive trials may be said to mark an epoch.
There is no reason to believe that any success attained with electric locomotives for a special train service is an indication of the method which may be developed for the replacement of steam by electricity for general main-line traction. If electric traction is to supersede steam on main railways, it will hardly do so by substituting one heavy hauling machine for another. The real method by which electric traction can show its advantages is undoubtedly that of some form of multiple-unit system, the motive power being distributed through the length of the train, and the control of all the motors being placed in the hands of a single motorman.
HENRY HARRISON SUPLEE.
It is part of the nemesis following the inordinate use of Greek and Latin as a means of education that the ancient classics have come to be popularly regarded as mere material for the school-room. The prejudice which attempted to retain for the classical studies a disproportionate share of the curriculum has been, in one respect, too successful, for the over-insistence upon their educational value has produced a general impression that this is their sole function. Accordingly, such a book as "LECTURES ON CLASSICAL SUBJECTS," by W. R. Hardie, Professor of Humanity in the University of Edinburgh, would not naturally be thought of as suitable for a birthday present, except possibly for a young man at college. The casual purchaser, looking around the shelves of a bookstore, would as soon think of taking home with him a treatise on conic sections to occupy the leisure of the winter evenings. A volume of essays on English or French literature might be supposed to have an interest for reader with the tastes of the average educated man, and might thus escape classification under the heading of "school-books "; but when the Greek and Latin authors are the subject of discussion, it is presumed that the appeal must be to specialists only, although the range of these authors themselves may be as wide as that of the most catholic of the moderns.
With the exception of the chapter on "The Metrical Form of Poetry," a subject necessarily technical, there is nothing in this collection of lectures that any one with an appreciation of literature, though not an expert in the ancient tongues, should find dull. For Mr. Hardie writes as a philologian in what, he reminds us, is the strict sense of that word. A logos is not, properly, a word, but "an argument or proposition, an intelligible statement; a group of words which conveys a meaning"; and consequently a philologos is "one who is interested in what men have said; in their intelligible utterances; the expression which they have found for their ideas and experiences." Thus in the study of the classical writings we have to do not only with the forms of
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