VENTILATION OF MINES 



1069 



sultation with Mr. Nasmyth, it was resolved to test the principle and plan by actual 

 practice ; and the ventilating fan described was erected at the Abercarn Collieries. 



The general arrangements of the top of the shaft and the ventilating fan are shown 

 in figs. 2085 and 2086. Fig. 2087 is a side elevation of the fan and engine, to a larger 

 scale; &n&.fig. 2086 a vertical section of the fan. 



The fan A A, fig. 2087, is 13J feet diameter, with 8 vanes, each 3 feet 6 inches wide 

 and 8 feet long. It is fixed on a horizontal shaft B, 8 feet 7 inches in length from 

 centre to centre of its bearings, which are nine inches long by 4| inches diameter. The 

 vanes are of thin-plate iron, and carried by forked wrought-iron arms secured to a centre 

 disk c, fixed upon the shaft B. The fan works within a casing, D D, consisting of two 

 fixed sides of thin wrought plate, entirely open round the circumference and connected 

 together by stay-rods ; the sides are 3 inches clear from the edges of the vanes, and 

 have a circular opening 6 feet diameter in the centre of each, from which rectangular 

 wrought-iron trunks, E E, are carried down for the entrance of the air, the bearings 



2085 



for the fan-shaft B being fixed in the outer side of these trunks, which are strengthened 

 for the purpose by vertical cast-iron standards F bolted to them, and resting upon the 

 bottom foundation-stone G. 



The two air-trunks E E join together below the fan, as shown in fy. 2085, and com- 

 municate with the pit H by means of a horizontal tunnel i, which enters the pit at 21 

 feet depth from the top. 



The fan is driven by a small direct-acting non-condensing engine K, which is fixed 

 upon the face of ono of the vertical cast-iron standards F, and is connected to a crank 

 on the end of the fan-shaft B. The steam-cylinder is 12 inches diameter and 12 inches 

 stroke, and is worked by steam from the boilers of the winding engine of the pit, at a 



