Extract from Kentish Mercury
Society of Engineers
On Friday the members of this society visited the Patent Concrete Stone Works at East Greenwich. At the former they were received by Mr. Fredrick Ransome, the Inventor of the ingenious and useful process by which the concrete stone is produced. There are many persons to whom it will appear hardly credible that an artificial substance superior to sandstone in durability and uniformity of texture, can be manufactured at a cost less than that of quarrying and cutting the natural stone. It is more than a quarter of a century since the idea struck Mr. Ransome that if he could only obtain sufficient powerful cement he could convert loose dry sand into stone. After long research, And having acquired a knowledge of the properties of every cement in use, he at last became acquainted with the important fact that It is possible to dissolve common flint, and thereby to obtain a material of the consistency of glue, and of great binding power. This was the key to his invention and after long and patient labour the result has been the establishment of the Patent Concrete Stone Company (Limited) and the erection of an immense manufactory on the southern bank of the Thames OD a place covered up until recently by an Ugly and pestiferous marsh. The various steps in the process are singularly interesting. In making the concrete, the materials used are principally fine sand, gravel, flint, limestone, caustic soda, calcium chloride and water; and it is possible to produce material of any degree of fineness or roughness from it the most delicate mouldings to the strongest “grinders”. The flints are boiled under pressure in a strong solution of caustic soda, and the thin solution or liquid silicate of soda thus obtained is evaporated down to the consistency of glue. The sand, which for the best descriptions to concrete is the finest quartzoac sand of Maidstone, is carefully dried by a hot blast passing through a revolving cylinder. A small proportion of carbonate of lime is added and the sifted sand is placed in the mill, where about one gallon of the viscid silicate of soda is given to every bushel. The mill kneads up and mixes the materials until a substance like putty is obtained. But this substance baked or hardened would not be Indestructible and perhaps the most ingenious feature of Mr. Ransome’s process is that which follows. By submitting the concrete while it is still moist and pasty to the action of a solution of chloride of calcium it changes in an Incredibly short space of time the irable plastic mass into a solid stone. The chloride combines with the soda of the silicate forming common salt; the calcium unites with silicic acid thus making an insoluble cement. The salt is afterwards washed out by shower baths and the blocks are then placed out to harden and to dry. This is a very brief description of a most valuable manufacture. The grindstones produced in this way are said to equal the best stones of Newcastle. The mouldings, the cornices and the ornaments manufactured equal in beauty and surpass in durability the best carvings of Portland stone, and the company is now producing an immense quantity of ornamental work
Greenwich Peninsula History 