electric machine connected to the bucket-chain which brings up the beetroots to be landed, and empties them into the trucks arranged for their reception.

Several such apparatus are placed along the quay, and can be set in motion by the workman by the simple means of a switch.

A similar though more complete installation has been put up by Dr. (now Sir) William Siemens in his English farm. In this case a portable engine in the central building sets in motion a Siemens dynamo. The different points where work is to be carried out are connected with the central works by conductingwires, some stationary, others movable and fixed at will. Dynamos are arranged where the work is required to be done, whether in the field, in the barns, or elsewhere; it is only necessary simply to connect the conducting wires with the machines. Thus, in every part of the farm, the current being produced in the central building by means of a steam engine may at any moment instantly be switched on for use. We We may add that the electric current thus generated is employed at night for lighting purposes, and has been used for very interesting experiments as to the development of vegetation under the influence of electric light.

CHAPTER VII.

TRANSPORT OF FORCE AT THE ELECTRICAL
EXHIBITION OF 1881.

THE Electrical Exhibition which took place at Paris in 1881, and which was so brilliant, contained numerous examples of the electric transport of mechanical work. We cannot say, however, that there was any very new revelation made on this point, except in the exhibits of Marcel Deprez, of which we will speak by themselves.

As to the rest, we find currents transmitted in a similar way to those of which we have been speaking: that is to say, worked at a short distance by means of machines of known patterns. Even from this point of view there was very little appearance of innovation; all the transports acted, with the above-named exception, by means of the two types of machines spoken of in the preceding chapters, the ordinary Gramme machine and that of Siemens. Among the numerous new forms of machines produced at this Exhibition, none were applied to this purpose. The study of the transport of force by electricity as shown at the Exhibition would be reduced to a very brief and dry enumeration, were it not for a few not uninteresting peculiarities of some of the exhibits.

Several

To dispose of the least important first. firms exhibited exhibited whole whole work-rooms of sewing machines, all driven by electric motors. All were arranged in the same way; whether they were exhibited by the firms of La Ménagère, or Baclé, by Bariquand or by Hurtu and Hautin, all consisted of a certain number of sewing machines connected mechanically with a common driving-shaft; a dynamo set this shaft in motion, and the machines worked. In all the exhibits just mentioned, the Gramme machine was employed.

It was the same with the machinery of Donnay Huré, Mouchère; the instruments worked varied, planes, lathes, etc., being shown in motion, but were always driven by a Gramme machine, receiving the current from a similar one placed at some distance in the Palais de l'Industrie.

Among the exhibits of this sort, the first to be mentioned is that of Heilmann, Ducommun, and Steinlin of Mulhouse. They set up on one side a regular battery of Gramme machines driven by steam-engines, and on the other a practical engineer's workshop, worked by a shaft driven by the other Gramme machines receiving the current of the first. The distance of transport was of course, as in the above-mentioned cases, very short; not more than 100 metres.

We must also mention Geneste and Herscher's installation; here a single generating machine served to set in motion three receiving machines. It was a sort of vague attempt at distribution of electricity,

of course very incomplete, but nevertheless interesting, and to be noticed as having some originality.

We now come to the exhibits in which the electric transport of force was the special object of demonstration. We will speak first of that of Chrétien and Félix. They reproduced at the Exhibition the electric plough executed by them at Sermaize, of which we have already spoken: there is no need to say any more about it, as the whole machinery was exactly as we have already described it; to this was added a new apparatus constituting a sort of railway. Strictly speaking, it was a truck something like the tender of a locomotive engine, the wheels of which were connected by an endless chain to a Gramme machine inside the truck; the current, brought by one rail, returned by the other, as in the Lichterfelde tramway described above.

The firm of Chrétien and Félix also exhibited a number of tools: for instance, a timber saw-mill in which the saws were set in motion by a Gramme machine; a rotary pump whose axis was connected direct to that of an octagonal Gramme machine. Last, but not least, was an atmospheric rock-borer, for cutting and detaching blocks of stone in a quarry; for this purpose it had a sort of solid scissor-blade, which moved with a rapid alternating motion, striking the stone, where it is required to be cut, a succession of rapid blows. This operation is accomplished by means of compressed air to make the blow more elastic. The electric machine was used to

give the rapid alternating movement to the piston working the apparatus. There was also to be seen a hammer, striking very rapidly and worked directly by a Gramme machine. This exhibit, as we may see, was important for its extent and the number of objects exhibited, but it added nothing on the whole to what had already been seen in France. The distance of transport was not more than the width of the Palais de l'Industrie.

Messrs. Siemens and Halske's exhibition was more original--indeed we ought to say exhibitions, for this noted firm exhibited in the German section as a firm, in the French section by right of their branch in Paris; in the English section in the name of Dr. (now Sir) William Siemens, brother to Dr. Werner Siemens, head of the German firm. A fairly interesting installation of a collection of tools was made by them in the French section; among them were much the same as the others-lathes, planes, rotary pumps, and besides an electro-plating bath. On this point an important remark must be made. We have already said that, to transmit force most economically and conveniently, electricity of high tension must be employed in order to use a smaller quantity; the contrary is the case for electro-plating. Experience shows that to obtain a metal deposit, the lower the pressure of the electricity the better. It follows from this, that the electricity used to transmit force is not fitted to deposit copper or gold. This defect is obviated by an ingenious contrivance: the electricity produced by the central engine is employed not to