oct. — dec. 1857] Mode of protecting Timber from Fire. 135 



The above report was accompanied # by a communication relating 

 to the cost of the application of the silicate coating, in which it 

 was stated that, provided the silicate of soda employed has been 

 prepared with especial reference to this application (». e. so as to be 

 readily and completely misceable with water,) one pound of the 

 material is sufficient to prepare a surface of wood of ten square 

 feet; while the wholesale price of the silicate, in the form of a 

 syrup of a certain degree of concentration, is twenty pounds per 

 ton ; so that the cost of the silicate, required to prepare the wood, 

 is at the rate of about two-pence for a surface of ten square feet. 



Experiments are just now being carried on, with a view to im- 

 part to the silicate coating the appearance of paint, by combining 

 the use of different colouring matters with that of the lime. 



The following are the directions adopted for general guidance, 

 in preparing wood with the coating of silicate of soda and lime. 



dleections fob covering tlmber with a protective coat- 

 ing of the Silicate of Soda and Lime. 



Materials employed. — The silicate of soda, must be in the form 

 of a thick syrup, of a known degree of concentration, as manufac- 

 tured by Messrs. Simpson and Co., Kennington Road, London. 



The lime-wash should be made by slaking some good fat lime, 

 rubbing it down with water until perfectly smooth, and then di- 

 luting it to the consistency of thick cream. 



Treatment of the Wood. — The protective coating is produced by 

 painting the wood, firstly with a dilute solution of silicate of soda ; 

 secondly, with the lime wash ; and lastly, with a somewhat stronger 

 solution of the silicate. 



The surface of the wood should be moderately smooth, and any 

 covering of paper, paint, or other material should be first removed 

 entirely, by planing or scraping. 



A solution of the silicate, in the proportion of one part by 

 measure of the syrup to three parts of water, is prepared in a tub, 

 pail, or earthen vessel by simply stirring the measured proportion 

 of the silicate with the water, until complete mixture is effected. 



