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outside the battery, becomes the "positive" and the zinc the "negative." Immediately the current goes out, the copper becomes positive. The flow of electricity is always in the one direction —from the positive to the negative outside the battery. The tramway companies use the positive pole of the dynamo on the line (the trolly-wire). They keep that line continually charged, and the other pole of the dynamo is connected to the carth —that is the single-trolly system. The electric current travels along the line (the trolly-wire), and, after it has done its work, passing through the motor, is discharged into the earth. The property of an electric current is to come back to its opposite pole by as many metallic paths as possible. The cause of the effects shown in the pictures I have produced is this: When the current leaves one metallic conductor for another it causes a sparking at that point, which in time dissipates the metal (eats it away). The current, in its flow, after leaving the motor, lays hold of all metal within its reach to arrive at its negative pole. Of that there is no doubt. 3. The Chairman.] I am not quite clear as to whether you mean the electricity would leave one line and become connected with another twenty chains away ? —Yes ; it would do so in the inverse ratio to the resistance offered to its path. 4. You mentioned that the current loft its own lino if it met with something better ? —Yes ; that is so. 5. Supposing it travels on this new conductor, and that was only half a mile long, would it return back to its own line ?—lt would get on to any metallic conductor in its path that would lead it back to its negative pole again through the earth. 6. Mr. Earnshaiv .] With regard to the current attracting all metal in its path :If the electricity goes on to the car wheels, and from them to the rails, that rail being in thorough order and in connection with the line to the central station; assuming that there is another cable also in connection, is it not reasonable to assume that will take all the electricity from the machine ? —No, it will not confine itself to the tram rails or to the cable unless they are insulated. If they are in connection with the earth, the electricity will distribute itself in the inverse ratio to the resistance offered. .7. Mr. Swan.] What is being meant by the " inverse ratio "?—lt is this : Say you have five conductors, each succeeding one twice as good as the former as regards its metallic conductivity : The electricity will divide itself and take hold of the whole lot of them and travel along them, the quantity of electricity on each conductor being in proportion to the respective conductivity of each conductor. 8. Mr. Lake.] They use the term, " discharge of electricity." Is there any such thing as discharge of electricity ?—Yes ; there is such a thing. 9. The Chairman.] Does depth in the earth make any difference to the cables ?—No difference at all, within certain limits, so long as there is anything like moisture between them. 10. Mr. Swan.] Have any trials ever been made, to know whether any current has been set up on water- and gas-pipes of their own, as independent from the introduced current which has been proved to exist ?—Not with two similar metals ; copper and iron would. Cast- and wrought-iron would not make a current. 11. Is there no possibility of another current? —No. As regards the latest remedy, by joining the rails with strips it becomes a good conductor so long as they are kept in good order. Copper and iron hate one another. Where the rails are on sleepers the very jarring weakens the rivetting, and space is created between the copper and iron. Into this space the water gets, and an electric action is set up, and day by day it gets worse. This is the weak point, and they are continually finding it out in America. I have not gone into the question of traction very much ; telephony and telegraphy are my special spheres. I am, however, quite certain that the process of using a single trolly is a very wasteful one. Looking at it from any view you may, you come back to the one conclusion, " That by the one-trolley system, a large amount of energy, which costs money to produce, is thrown away." 12. Mr. Lake.] A certain part of the energy used for the purpose of the tramway would be lost in setting up the action ?—The current generated in any system is governed by the electric motive force divided by the resistance, which also includes the back electro-motive force of the moter. Take the friction of water in a tube. The quantity of water delivered in unit time is governed by the pressure and the frictional resistance of the tube. Now, in regard to the tram-cars, the mere fact of the wheels rolling round—being the only means of connection with the ground system —it is known that the wheels do offer resistance to the current passing from the axles to the wheels on to the rails. I have calculated that they must lose quite 30 per cent, of their energy at times through the fact of the continuity of the metallic conductors not being perfect. [In a Journal to hand since this evidence was given, it is put down at 33J per cent, loss.] 13. Mr. Swan.] Does that apply to the double as well as the single-trolly lines ?—No. The double is insulated. The current goes right back again. It only loses the energy which it has to exert in overcoming the resistance of the conductor- which, if you make it large, becomes little or nothing. You get the whole of the energy generated for useful work, minus what is lost in resistance. 14. Mr. Lake.] As I understand the claim of the Government, it is that they have a vested right in the earth-return for their discharge of electricity from the telephones?—-We have been in undisturbed possession of this earth-return for the last sixty years. In a portion of Mr. Baron's evidence, I notice that he said that Edison attributed the discovery of the principle of the earthreturn to Steinheil or Morse, in 1835. Now, I may tell you that when the telegraph system was first inaugurated they used a return-wire. In 1837, a man named Steinheil discovered—or rather re-discovered, I should say—that they could do away with the return-wire and use the earth instead. It has been the common acceptance that Steinheil discovered it; but in volume 9of the "Transactions of the Royal Society," page 490, it is shown that the discovery of the earth-return was made by William Watson and others in the year 1747.