310 Intelligence and Miscellaneous Articles. 



reous or other matters of inferior conducting power deposited from 

 the water by electrolysis, which soon diminished the available power 

 of the coil to a considerable extent, I was induced to invent a regu- 

 lator in which liquids were dispensed with, and consequently all 

 electrolytic action avoided, and which, whilst being unaltered in 

 conducting power by long-continued use, possessed that valuable 

 property of the water- regulator, — of enabling the power to be regu- 

 lated by inappreciable degrees instead of by sudden increases and 

 decreases, as in all other kinds of coil regulators. 



The regulator I invented and have used in several instances for a 

 considerable period may be formed as follows : — Take equal quan- 

 tities of gold bronze powder, finely powdered black-lead, and finely- 

 powdered rotten-stone, and form them into a series of separate 

 powders, each of equal quantity, to the number of eighteen or twenty ; 

 let the first consist entirely of bronze powder, the second of nearly 

 all bronze powder with a little black-lead, the third with an increased 

 proportion of black-lead and less bronze, and so on increasing the 

 proportion of black-lead and diminishing that of bronze in a regular 

 manner until you come to the middle powder, which should consist 

 entirely of black-lead ; then begin to form them of black-lead and 

 rotten-stone, gradually decreasing the former and increasing the 

 latter until you come to the last one, which should consist entirely 

 of rotten-stone ; well mix each powder, and keep them all separate 

 and in order : now take a moderately strong solution of shell-lac in 

 alcohol or in vegetable naphtha, and with equal quantities of it form 

 each powder into a rather firm paste, which should be put immedi- 

 ately into small bottles numbered according to the composition of 

 the paste and corked up ; now take a glass tube of about 3 or 4 

 inches long, and about \ or f of an inch in internal diameter, and fix 

 a cork in one end with a hole \ of an inch in diameter in it, through 

 which fix a glass or metal tube of that diameter within the outer 

 tube and of the same length ; also take a metal or glass tube of a 

 size and length suitable for ramming the composition in the annular 

 space between the two tubes, and with it carefully and firmly ram 

 equal portions of all the pastes into the space, commencing with 

 that formed entirely of bronze powder, and passing on in regular 

 order through the series to the last — that formed entirely of rotten- 

 stone, when the tube will be about filled ; now carefully withdraw 

 the internal rod or tube, and set the composition tube in a dry place 

 for several days or a week until the whole of the spirit has evapo- 

 rated and the composition has become quite dry and hard, when you 

 will have a tube of good electrical conducting power (for induced cur- 

 rentsof the usual intensity)at one end, and gradually decreasing in con- 

 ducting power until at the other end it is an excellent non-conductor. 



To complete it as a regulator, fix a metal cap on the bottom or 

 bronze powder end and in close contact with the composition, also fix 

 another metal cap on the upper end with a regulating rod to work 

 up and down in it as in the ordinary water-regulator. The regula- 

 ting rod should be formed of thin, smooth, brass tube, of a size to slide 

 loosely within the composition tube, and slit at its lower end for 

 about | of an inch, and sprung slightly open at that end so as to press 

 steadily and smoothly upon the internal surface of the composition. 









