THE USES OF PHOSPHORESCENCE. 165 



the painting of houses, so that they will render the streets 

 luminous ; buoys at sea ; even the hulls of ships and their 

 sails might be made conspicuous in this way. In London 

 the harnesses of horses engaged in night work have been ren- 

 dered luminous by this paint ; and its availability in mines, 

 and in large sewers like those of London, tunnels, and other 

 subterranean works can hardly be estimated. Artificial fishes 

 are painted, and used as luminous bait; and toys innumer- 

 able are placed upon the market, made interesting by applica- 

 tion of this discovery. 



It is obvious that luminous paint cannot be used in some 

 cases, and to take its place Messrs. W. C. Home and E. 

 Ormerod of London have recently invented a method of 

 utilizing the luminous powder prepared mainly as a sulphide 

 of calcium, for admixture with cements, plaster of Paris, 

 and concrete, the object being to prepare the articles with 

 a self-contained phosphorescent property instead of coating 

 them with luminous paint. They take the proper proportion 

 of any suitable cement, with the right amount of the lumi- 

 nous powder, mixing these with water, and moulding it to 

 the required shape in the usual way, after which it is laid 

 on the ceilings or walls with a trowel. The patentees attach 

 importance to placing the moulded articles, as soon as dry, in 

 a bath of parafnne wax and benzoline, or other water- 

 proofing substance equally good. 



In the case of using the luminous cement upon a wall or 

 ceiling, they sponge or brush the surface over with a solution 

 of parafnne wax and benzoline, or other suitable damp- 

 proofing solution. The uses of a luminous cement are 

 manifold ; e.g., for the garden, luminous concrete as edging 

 to garden-paths and carriage-drives ; for guides and beacons 



