AN INGENIOUS CONTRIVANCE.

New Zealand Times, Volume XXXIII, Issue 5502, 14 November 1878, Page 2

AN INGENIOUS CONTRIVANCE.

The following remarks made at the meeting of the Philosophical Society on Saturday by Mr. Kebbell, in explanation of his lamp for heating clo-ed rooms :—The object of the apparatus before us is to keep the cloakroom of the Observatory at an equal temperature, which is of great importance to the regularity of the rate of a clock. I had been for many months trying to scheme a burner that would he self-acting, simple, and not likely to get out of order. I proposed availing myself of the expansion of springs, levers, and'several other ways attached to a cock, but cocks occasionally will stick, and are uncertain in their action. Levers, or the expansion of springs, answered in Dr, Arnot'a stove; but then the valve regulating the admission of air . rested on kite edges without friction, eo that I was in despair, when the thought occurred, could I get sufficient expansion of mercury in the neck of a bottle it would solve the difficulty with great simplicity. Upon filling this bottle with mercury I found that in raising the temperature 20dega. the mercury rose half an inch, ample for the purpose. It then only required to have the detail worked out, which consists of a lantern, inclosing an argand burner, and close to the holes of the argaud a email burner, with a hole smaller than any hole in the argand, which is kept constantly alight from an independent source, and perhaps will cost from threepence to sixpence a week for gas. The other part is a glass bottle, with a glass tube attached to the neck, filled with mercury to about half way up the glass tube ; on the .top of the glass tube is a square brass attachment, with 'a cock on each side ; on the upper aide is a stuffing-box, through which slides a brass tube into the mercury ; the brass tube has two slits, to allow the gas to pass when the room and the mercury have cooled sufficiently and shrunk down, in the glass tube, it then passes up between the brass tube and interior of the glass tube as far as the stuffing-box, then through one cocks to argand-burner—the use of this cock is to prevent more gas passing than the argand can consume, or there would be smoky glass and pipes. The use of the other cock is this : Should the lamp be out through • the room being up to its required temperature, by turning this cock the lamp may be used as an ordinary lamp, or another would be required for working out the calculations. There was another difficulty to be got over—-the combustion of gas in a closed room would injure the clocks. Professor Piazzi Smith, Astronomer Royal,of .Edinburgh, I recollected, got over the difficulty by having a thin metal tube laid round the room, of sufficient length to extract the heat, and then outside he found the condensed products of combustion provided as much water as he required. At the back of the lamp I have made provision to take the air necessary to supply the burner from outside the room, or the sudden opening of a door would draw the air back down the escape tube and extinguish the light. ,