Materials for the Construction of Cottages. 565 
the chimney is made use of, and the room, instead of being filled "vvith 
cold air thi'ough the dooi* or ^^indow, is supplied with moderately 
warm air. I'his stove is, moreover, a remedy for that very great evil, 
a smoky chimney. The only reason why smoke does not as readily 
go out of the door or window as up the chimney, is, that the 
air in the chimney is rarified ; the more it is rarified, the 
better smokc-flae, or smoke-shaft, it becomes. But in an ordinary 
fire-place the air rushes up and makes the chimney cool ; and 
thus it becomes such a bad smoke-shaft that the least opposition — 
fire burning in another part of the house, and a himdred other causes 
— cause smoke to appear in the room. Xo air could pass up his 
chimney but v.hat had become heated ; and thus the common smoke- 
flue is made not only a perfect smoke-di'aught, but also a valuable 
shaft for the pui'pose of ventilation. The clever contrivaaice of Dr. 
Arnott had tlic effect of preventing any down draught ; that is to say, 
the moment the flue becomes impleasant as a ventilating shaft, as is 
frequently the case, Dr. Amott s valve operates as a check. Ho would 
not then enter into the question how fai" that valve is sufficient for the 
purpose. Stains of smoke are often produced by it ; and it is not 
every one who can bear the noise and flapping which the valve pro- 
duces. In his o^\Ti flue there is no necessity for any contrivance of 
that description. He merely made an ordinary opening into the 
smoke-flue, being quite certain that as long as the smoke was burning 
it could be used as a powerful extracting shaft for ventilation. These 
fii-e-places have perforated tiles and iron work, which stand in fi-ont 
of the fii-e-lumps, and present an ornamental appearance in the room. 
He thought he had now occupied the time and attention of the meeting 
long enough ; but he should be happy to answer any questions which 
might be put to him. 
In answer to an inquiry how these chimneys were swept, Mr. 
Taylor said that about every six weeks or two months a broom was 
used, which was made like a ball, with a string and bullet. A clerk 
in his office swept his chimney without soiling his hands. He put his 
hand up, and a bullet dropped on to the bottom heai'th, where the cinders 
generally di-opped. The bullet deposited the soot on the hearth, and 
it was taken away with the cinders. This plan had been in operation 
for two or thi-ee yeai-s, and he had never been troubled with a particle 
of soot. Sometimes the register was left open, in order to cool the 
room. He thought that a sweep would not be required more than 
once in five or six years. 
Mr. Bailet Dextox believed that no lecture was ever prepared with 
greater care than this ; that Mr. Taylor's inventions were exceedingly 
ingenious, and would come into extensive use ; but still the question 
xecm-red, what would be the expense of building these cottages ? His 
own experience in cottage-building was not small, and, taking advan- 
tage of every improvement that had been made, he did not see how 
cottages were to be built for less than 120/. each, supposing that they 
were built in pairs, with three bed-rooms, that sanitary requirements 
were respected, and that the requirements of the Enclosui'e Commis- 
