paper well known as the carbonic ink paper. The slowness with which signals would be rendered, as compared with the needle instrument, has prevented this grand invention of Wheatstone's from being, as yet, brought much into use. Mr. Bain has also distinguished himself by successive inventions of an improved electric clock and telegraph; but neither have these been brought into general use.

The

In 1843, Mr. Cooke introduced the most important improvement, regarded in a commercial point of view. This was the suspension of the wires, in the air, upon posts or standards, for insulation, instead of conveying them under ground. wires do not come in contact with any part of the standard, but pass through rings of earthenware. Iron wires of a large size can thus be used, instead of copper, and the cost of constructing a telegraph reduced one-half.

The needle instrument, from the great rapidity with which messages can be sent, has hitherto obtained the preference over Professor Wheatstone's electro-magnetic telegraph, in England; but the latter is in use in France, and has there been entirely approved of. Within the last few years, too, a great and important improvement has been introduced into Wheatstone's invention, by the use of the electric current derived by induction from a permanent magnet, instead of the voltaic battery. This plan is not applicable to the needle instrument, but is peculiarly so to the electro-magnetic telegraph.

The extent to which the Electric Telegraph has been brought to bear in England, may be judged from the fact that, at the present time, about two-thirds of the railways already constructed are supplied with telegraphic wires. The result is the establishment of a complete system of communication between every important town in the kingdom with a central office in the metropolis, adjacent to the Bank and Royal Exchange, at which the whole telegraphic news of the country is concentrated and forwarded in every direction. Indepen

dantly of the immense advantage which a system like this presents to the government and the trading and commercial classes of the country, it has the advantages of being conducted on such a moderate scale of charges as to bring its beneficial influence within the reach of private individuals, who, for a few shillings, may transmit a message containing twenty words something like a hundred miles in the course of a few seconds.

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