the Water while Shafts or Pits are s'lnkivg. 363 



Viery low in the pit, the engine of course frequently goes 

 too fast, and carries up by the violence of the current small 

 pieces of stone, coal, or other substances, and lodges them 

 above the bucket, which must considerably retard the 

 working of the pump, and wear the leather. 



Secondly. — When the engine is set to work, (after hav- 

 ing been stopped whilst working upon air, and consequently 

 a quantity of air remaining in the suction-pipe, with the 

 small stones, &c. deposited on the valves of the bucket,) it 

 often happens that the compressure of the air by the descent 

 of the bucket is not sufficient to overcome the weight of 

 the bucket valves so loaded with rubbish, and the column 

 of water in the stand pipes, the pump is hereby prevented 

 from catching its water; the usual remedy for which is, to' 

 draw the bucket out of the working barrel, until a quantity 

 of water has escaped bv its sides, and displaced the air. 

 Observe here, that this often happens from, the unnecessary 

 matrnitude of the space between the bucket and clack. 



Thirdly. — The pumps are suspended in the pit by capstan 

 ropes, for the purpose of being readily lowered as the pit is 

 sunk ; the stretching of the ropes (especially when sinking 

 in soft strata) occasions much trouble, by suffering the 

 pumps to choke; but the most serious evil is, that the 

 sinkers, in shifting the pumps from one place to another, 

 throw them very far out of perpendicular, thereby causing 

 immense friction and wearing in all the parts ; besides cn- 

 dangerino" the whole apparatus, by breaking the bolts and 

 stays, and straining the joints. 



Fourthly. — As the pumps sink, the delivering pipe at the 

 top is raised, by putting on short pipes, generally abcjut a 

 yard at a time, which occasions many stoppages and much 

 hinderance in the work. 



Having an engine pit to sink at Codnor Park Colliery, 

 Derbyshire, belonging to the Buttcrley Iron Company, I en- 

 deavoured to obviate^the difficulties stated ; and, first, for 

 the purpose of preventing the pumps working too much 

 upon air, I constructed a working barrel, (which in this 

 case was nine inclics diameter,) with a side pipe three inches 

 diameter, connected therewith by an opening at the top and 

 bottom ; also at ^be upper end of the side pipe I fixed a 

 valve, so as to slide over and shut the communication with 

 the working barrel, the stem of the valve bv which it is re- 

 gulated, passing through a stuffing boX; and by letting a 

 (piantity of water return through the side pipe, o the bot- 

 tom of the working barrel, (the men at the bottom regu- 

 A a 2 Jating 



