1868. | Ransome’s Patent Conerete Stone. 163 
but that the means also existed of restoring those disintegrated 
particles to their former consistency and hardness. Thus far 
Mr. Ransome had succeeded in dissolving his flints, but he found, 
on mixing his silicate of soda with sand in moulds, that the ap- 
plication of heat for the purpose of reindurating the silica failed to 
give satisfactory results, for the surface first naturally became hard 
and was cracked by the escape of the moisture from within. 
The desired end was therefore not yet attained, but Mr. Ransome 
persevered in his experiments, and seemed gradually approaching 
towards more satisfactory results, when, about the year 1852, the 
discovery that the stones with which the Houses of Parliament 
at Westminster had been built, were beginning to show signs of 
decay, caused his attention to be directed to the discovery of some 
means whereby his solution of silicate of soda could be applied, so 
as to give an indestructible surface to the stonework. “He had 
not proceeded far in the application of soluble silicates to this pur- 
pose before he found that, although the theory with which he 
started was alike pretty and plausible, in practice the results were 
imperfect, inasmuch as the substance applied as a preservative being 
in itself soluble, the ordinary humidity of the atmosphere, apart 
even from the more powerful action of showers of rain, would, at 
least partially, dissolve and wash it away. Mr. Ransome’s numerous 
experiments at this juncture, about 1856, were directed to the dis- 
covery of means for converting the soluble into an insoluble silicate, 
so as to render the effect perfectly independent of extraneous action 
and conditions. It occurred to him that if a compound silicate of 
lime—the substance which has given such enduring properties to 
the old mortars of the ancients, which have remained unchanged 
for thousands of years—could be formed in the structure of the 
stone, that agent would not only possess the property of perfect 
insolubility, but it would also most effectually envelop and bind 
firmly together, by an indissoluble bond, the several particles of 
which the stone 1s composed. After numerous experiments, de- 
signed to reduce this principle to practice, he found that the ap- 
plication of a solution of chloride of calcium (or lime dissolved in 
muriatic acid) formed, almost instantaneously, with the silicate of 
soda previously used, by double decomposition, an insoluble silicate of 
lime, and a soluble salt of chloride of sodium, or common salt, which 
latter substance is easily removed by subsequent washings.”* Sub- 
sequent experiments having proved the readiness with which this 
principle might be applied to the preservation of natural stones 
from decay, Mr. Ransome next turned his attention to the manu- 
facture of stone by the same process. The results proved as satis- 
factory as could be desired, and in 1863 a joint stock company was 
formed with a view to carry out operations on a large scale. 
* ¢ Engineering,’ December 7, 1866. 
