60 General Notices. 



French author, and it is put in practice every day, on a small scale, and 

 with different materials, by gardeners, who roll their gravel walks or ap- 

 proach roads with rollers which press on every part of the surface with 

 triple the effect that men, horses, and coaches can do. In consequence of 

 this, the walks are smooth, and the approach roads without ruts. — Cond. 



Fire-proof Floors and Roofs. — Mr. Frost, of No. 6. Bankside, builder 

 and cement manufacturer, has just described to us his mode of constructing 

 floors to houses of hollow earthenware tubes and cement, combined in such 

 a way as to form a floor as strong as one of timber, and much more imper- 

 vious to heat, cold, sound, or smells. The hollow tubes are square in the 

 section, and are made of brick earth, prepared in a very superior manner by 

 machinery ; they are placed in strata in opposite directions, and cemented by 

 a new and very superior cement of Mr. Frost's invention. We have not time 

 at present to enter into details ; but it may suffice to say, that the floor or 

 flat roof produced by Mr. Frost's process is in effect one flag stone (only 

 not a fifth part of the weight of solid stone) of a size sufficient for the 

 space to be covered. The invention appears to us of immense importance 

 with reference to fire-proof buildings ; and we shall have much to say on it 

 in our next Number, and in our Encyclopedia of Cottage Architecture, now 

 nearly ready for the press. In practice this mode of flooring and roofing will 

 not be more expensive than the common mode, the material costing little,and 

 the whole of the effect being the result of labour. Notwithstanding the im- 

 mense importance of this invention, especially for small and middle-sized 

 houses, we can foresee that it will be extremely slow of introduction, because 

 it will cut deep into the trades of the timber merchant, carpenter, and 

 plumber. It must, however, finally prevail. It is pleasing to think that, 

 by Mr. Frost's fire-proof houses, and Mr. Witty's smoke-consuming fur- 

 naces, London might become a city of flat roofs covered with gardens of 

 pots. We sincerely wish some man of property would take Mr. Frost by 

 the hand ; he would be found a scientific builder of many years' experience, 

 and well acquainted with the principles of mechanics and chemistry, and 

 their application to architecture. — Cond. 



Mr. Frost's Cement is thus formed : — Chalk is ground very finely in a mill, 

 and, as it is ground, mixed with water, which conveys its lighter particles to a 

 reservoir. Clay is grinding at the same time by the same machinery, mixing 

 with water, and conveying its lighter parts to the same reservoir. This com- 

 bination of chalk and 30 per cent of clay is drained and left to evaporate to 

 dryness. The stratum is then broken up, burnt in a kiln, and after being 

 ground to powder, is put into casks and hard pressed. It will thus keep 

 for any period, and may be sent to any distance. It is much cheaper than 

 Roman cement ; and has this great advantage for country use, that it re- 

 quires no sand to be mixed with it. It appears to us that garden walls and 

 cottages might be formed entirely of this cement, arrangements being 

 adopted to have what is usually built solid made cellular. It would suit 

 admirably for building houses in warm climates. [This and the preceding 

 paragraph were in type in April last, before we left London on our tour, 

 and have, unfortunately for Mr. Frost, stood over ever since. We hope, 

 however, to make amends for the delay, by prevailing on some friend, who 

 has the money to spare, to erect a fire-proof cottage on a piece of ground 

 at Bayswater, which we shall point out. We hope some moneyed reader 

 will volunteer his assistance on this occasion.] — Cond. 



Zinc, rolled into large plates, is now a good deal employed as a substitute 

 for lead and slates, in the roofing of buildings, both in Britain and on the 

 Continent. The great advantage of these plates of zinc is their lightness, 

 being only about one sixth part of the weight of lead. They do not rust, 

 which is another great advantage, and has led to the employment of zinc 

 pipes both for cold and hot water. {Brewster's Journal.) No covering is 

 better adapted for verandas and summer-houses. — Cond. 



