178 t^uggestions for the better Ventilation of 



without air-shafts." At the mouth of the adit, a chimney, 

 30 feet high, was raised, having a fire-grate ci-adle placed 

 within it, with a close ash-pit, and a tube fitted below the fire 

 communicated with parts where the air was to be replaced. 

 It is a somewhat remarkable coincidence that this method is the 

 very same, which, in 1836, 171 years after, has been success- 

 fully applied by Dr D. B. Reid, to extract the vitiated air from 

 the present House of Commons. Indeed, it seems naturaltosup- 

 pose, that the principle of creating a current by fire-heat, or, in 

 ventilation, drawing off foul air from one part to be replaced 

 by fresh, must have been the most self-obvious principle which 

 mankind in all ages and in all countries could apply ; hence 

 various attempts have been made to use this principle of ven- 

 tilation at different times, and sometimes it has proved suc- 

 cessful. Dr Desaguliers, in his Mechanical Phil. 1744, seems 

 to claim the merit of having first applied fire-draught suction 

 to buildings in this country, although he appears to have dis- 

 approved, or at least not recommended it for ships, and com- 

 plains that Dr Hales seems to have overlooked, in his book, the 

 great exertions he had made in this same field for twenty- 

 eight years. He says, that in 1715 he published a translation 

 of a French book called Mecanique de Feu, by Monsieur 

 Ganger, entitled " Fire Improved,'' &;c. ; and that in 1723 

 for clearing the air of the House of Commons, foul air grates 

 were fixed under his direction in the closets above the House 

 to suck out the impure air. This appears to have been the 

 first application to buildings of the principle of mine ventila- 

 tion by fire-draught, recommended by Sir Robert Moray ; and 

 which 'plan, though long in use for mines, has only within these 

 few years been revived in Britain for domestic purposes. But, 

 perhaps, amongst the oldest plans for the ventilation of coal- 

 pits is that of producing a current or increased circulation of 

 air by the use of large tires* at the foot of the upcast shaft. 

 It is somewhat singular that, when Sir G, O. Paul, Bart., in 

 1801, brought before the Society of Arts of London a grate 

 which he had invented for consuming the foul air which col- 



* It has perhaps been known for centuries that the circulation is increased 

 by kindling a fire at the top or bottom of one of the shafts. 



