272 
POPULAR SCIENCE REVIEW. 
burnt merely in order to be got rid of. It certainly seems as if, according 
to Professor Ansted’s suggestion, some legislation were necessary to prevent 
this wanton destruction of an element so essential to the well-being of our 
manufactures. We trust Government will soon take the matter in hand. 
Explosions of Steam Boilers . — That the influence of the association for 
the prevention of these fearful accidents is a beneficial one is shown b}' 
Mr. Fletcher’s report to a late meeting of the society. During the previous 
month there had been no less than three hundred and thirteen engines and 
four hundred and seventy-one boilers examined, of which five were frac- 
tured, fourteen were in a state of corrosion, and seven with safety-valves out 
of order. There were nine explosions during the month, by which five 
men were killed. It is satisfactory to know that none of these boilers were 
under the inspection of the society, and that in one of them the injuries 
were so well marked that they could not have escaped the detection of a 
skilled inspector. 
Utilization of the Cinders from Puddling and Reheating Furnaces. — A 
process has recently been proposed for the extraction of iron and steel 
from the refuse of the above-named furnaces. The cinders — which 
are usually rejected from the circumstance that they contain large quan- 
tities of sulphur, silica, &c., inseparable from the iron— are extremely 
valuable, and contain from twenty-five to fifty per cent, of the latter metal. 
The following is the method adopted : — A quantity of unslaked lime is mixed 
with fine-ground cinder, and then wetted and exposed to the air, when 
during the process of slacking, the lime and silica unite. The mass is now 
removed to a puddling furnace and heated. The result is, that about fifty 
per cent, of wrought iron is obtained. It is, however, tainted by sulphur, 
to remove which it becomes necessary to dissolve chlorine salts in the 
water used in slacking the lime. The pecuniary expenditure is not 
considerable, and a great saving of material is achieved.— United States 
Proposed New Form of Siemens Furnaces. —It is proposed to apply 
Siemen’s furnace in a novel way. M. Desmarest thinks it of advantage, 
in certain processes in which there are two consecutive stages in the opera- 
tion requiring different temperatures, to employ double furnaces, so that 
the; two connected processes may be carried on in the same apparatus by 
reversing the currents of heat. For the details of the apparatus, we must 
refer the reader to the Mining and Smelting Magazine for October. 
Ventilation of Collieries. — A successful instrument for this purpose has 
been recently tested at one of the mines near Tenby. It consists of a large 
circular fan of about eighteen feet in diameter by four feet, breast, and is 
arranged in such a manner on the surface, over the upcast shaft, that it 
absorbs without leakage all the gas and foul air of the colliery. From this 
it is thought that it may supersede the furnace at the bottom of the shaft, 
and which is frequently dangerously close to the large subterranean reser- 
voirs. The fan is driven by an engine at the rate of about one hundred 
and twenty revolutions per minute. — The Artizan for November. 
Extraction of Thallium from the Flue Dust of Pyrites Burners. — The manu- 
facture of this metal on a large scale is minutely described by Mr. 
Crookes, The process is as follows : — -The dust is first placed in wooden 
