IS8 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNTAL. 



[June, 



the influx of air from the down. cast shaft, ami in less tlian five minutes 

 the » liiile of tlie colliery was thus artificially sulijected to a rarefaction equal 

 to. am] in its effect upon the gas in the coal corresponding with, a sudden 

 fall of the harometrical column of about two-tenths of an inch of mercury, 

 and tliis may be greatly increased. 



To this capability of drawing ofT at pleasure the carburetted hydrogen 

 from the goafs and fissures, during the absence of the workmen and their 

 lights, and the re-introduction of fresh air before the men resume their 

 work, when the colliery will be found in a state of extraordinary purity of 



atmosphere, the inventor looks with great confidence as the most efl'ectual 

 means of preventing fire-damps, and also of promoting the health of the 

 workmen. Mr. Calvert, a large coal proprietor, one of the gentlemen 

 present, was so satisfied with the utility of the machine, having been under- 

 ground duiing its operation, that he has since given Mr. Brunton aa order 

 for one to be fixed at liis colliery immediately. We congratulate Mr. Powell 

 on being the first to introduce so valuable an invention — the adoption of 

 which, we trust, will be the means of saving the lives of many of our 

 colliers. 



PATENT BRICK AND TILE KILNS. 



These kilns are introduced by the Ainslie Brick and Tile Ma- 

 chine Company, for burning bricks, tiles, and pottery ware, and 

 are constructed on an entirely new principle, viz. : — that of burn- 

 ing (lotvitwanl.t, in ])laee of upwards, in a close kiln, and of apply- 

 ing the surplus heat of the burning kiln, which is now lost, to the 

 complete drying and partial burning of the goods in the series of 

 kilns in connection. Their superiority to ordinary kilns consists — 



Fint — in a saving of fuel of more than three-fourths. The 

 amount of fuel consumed in burning goods made from clay varies 

 materially, according to the nature of the clay. The clay at the 

 experimental works of the above company, at Alperton, is the 

 London clay, and is very strong. In a veiy good kiln there, of 

 the old construction, the quantity of coals used in burning 1.5,000 

 pipes of 1,|, inch diameter, 12 inches in length, is about 11 tons: 

 whereas, in one of the company's patent kilns 25,000 of the same 

 sized pipes, of the same clay, are burnt in a very superior manner 

 with only 1 ton and It to 16 cwt. of coals; a'nd in another of 

 larger dimensions, more recently erected, lOjOOO of the same sized 

 pipes are burnt with only 2^ tons ; and when the series of four is 

 complete, the company entertain no doubt of being able to burn 

 55,000 of such pipes with one ton of coals, or less than 1 cwt. per 

 1000. 'l"he kilns are equally adapted for wood and peat fuel. 



Sflroiid — Tlie saving in time. In a kiln of the description com- 

 moidy used, the firing must be kept up for three or four days, but 

 in the patent kiln, it is only necessary to fire 2G to 2H hours. 



Tliird — their superior cfl^ciency. In the common kilns, the loss 

 in breakage, and in over and underburnt goods, runs from 5 to 20 

 l)er cent., whereas, in the kiln here shown, there is no loss what- 

 ever. 



Fourth— the. great simplicity. For burning tlie old kiln, con- 

 siderable skill and great experience are required, whereas, the 

 liatent kilns can be managed by the most inexperienced work- 

 man. 



Fifth. — As the same heat is made to pass through a series of 

 two, three, or four kilns in succession, the last of the series is used 

 only i'or the purpose of shm-dryimj, and the goods are placed 

 m the kiln as soon as they have aciiuired sufficient consistency to 

 bear the superincumbent weight. The advantages of this arrange- 

 ment are, that in fine weather the goods can be placed in the kiln 

 the first or second day after they are made; in moist weather, in three 



or four days thereafter; and the operation of brick and tile mak- 

 ing can thus be carried on throughout the whole year, with the 

 exception of the time of frost, — in place of five or six months 

 only, according to the old system; and an immense saving in the 

 extent of drying sheds is also thus efl^ected. 



Sixth. — These kilns are so constructed as completely to consume 

 their own smoke. 



Seventh. — A single kiln on this principle Ciin be used, but the 

 saving is greater in using the series. 



The kilns may be seen in use at the Tile Works at Alperton, 

 near Acton, Middlesex. 



ON THE SEWERAGE AND OTHER WORKS OF 

 CHESTER. 



A very able Report to the Tovvn Council of the City and Bo- 

 rough of Chester, on the Sewerage and other works under the 

 Improvement Act, has just been issued by Mr. Baylis, the Borough 

 Surveyor, from which we make the following extracts. 



The Report commences by showing that the mortality of Ches- 

 ter is at the rate of ] out of 32'() of the population ; ami tliat the 

 unhealthy state of the city may be greatly attributed to the im- 

 l)roper supply of water, pumped up from the river without filter- 

 ing. 



It next describes the present system of sewerage, and gives a 

 tabular statement of the old sewers, and the length of new sewers 

 required. The following table will show the proportions and the 

 cost : — 



Estimate fur completmr/ the system of Sewerage, including the Cross 

 Drains, Traps, Gratings, ijC. 



^ H233 4 



Sewerage. — .Muih dilTerence of opinion exists as to the proper size for 



