Progress of Invention. 147 



to have been overcome by a lamp maker of Paris. Instead of 

 charcoal points he employs an apparatus of glass, within which the 

 air is greatly rarified, so as to allow a passage to the electricity, and 

 afford a mild light, something like that of an anrora borealis, but 

 quite sufficient for the miner. As this lamp produces no heat 

 whatever, it is impossible for it in any circumstances to ignite 

 an explosive mixture of gases. The galvanic battery it requires is 

 enclosed in a small box, which is carried on the back of the miner, 

 or is placed in any convenient situation near him. 



Mr. Stewart Harrison's Self-acting Preserver Valve, for 

 the Preservation of Life and Property from Eire. — This valve 

 is part of a system designed by the inventor to prevent the occur- 

 rence of fires, in the official sense of that word, by extinguishing 

 them at their commencement. He proposes that in warehouses, at 

 the docks, in public buildings, libraries, etc., wrought-iron pipes 

 connected either with a tank on the top of the building, or with 

 the fire mains in the street, shall be put up on the ceiling of each 

 floor, so as to divide the surface to be protected into spaces, greater 

 or less, according to the combustibility of the goods. To these 

 pipes. the preserver valve is to be attached. The valve, which is 

 globular in form and perforated with numerous holes, is kept closed 

 by a screw passing through a stirrup of brass, whose ends rest on 

 two small pins of fusible metal, which melts at 212 degrees Fahr, 

 Upon a fire breaking out, the heat ascending to the ceiling, 

 and melting one of the pins belonging to the nearest valve, the 

 water is poured down on the precise spot at which the fire 

 is commencing. Should the heat be sufficient, it will melt 

 several of the pins immediately surrounding the central point, 

 and the water falling on the goods below will prevent the 

 spread of the fire to them. In this way, it is believed by the 

 inventor that it would be impossible, with a proper supply of water, 

 for the damage under any circumstances to be very great. For 

 libraries, dwellings, etc., the valve can be concealed beneath orna- 

 ments on the ceiling, without any disfigurement to the rooms in 

 which it is fixed. For ships and steam- vessels, where a large tank 

 of water is not possible, the pipes run along the beams, and are 

 connected with a cistern on the highest part of the deck. When the 

 valve opens, the altered level of the water in the cistern causes a 

 float to sound an alarum ; on which the ship's fire-engines are con- 

 nected with the system of pipes, and the water from them is directed 

 exactly on the seat of the fire. The water is not, therefore, as at 

 present, blindly thrown wherever the smoke may appear (however 

 falsely) to indicate the part on fire, injuring the cargo as much as 

 the fire itself. Mr. Stewart Harrison has also designed an alarum, 

 which sounds whenever the water flows through any of the valves, 

 thus giving timely notice to the watchman, porter, or passer-by, that 

 the fire is being put out, and enabling them, on its being extinguished, 

 to prevent further damage by turning the water off from that set of 

 pipes. The valve and alarum, we believe, can both be seen in action 

 at the inventor's, No. 133, Upper Thames Street, E.C. 



Miscellaneous. — The lime light has been applied to the produc- 



VOL. VII. — NO. II. L 



