Drainage by Steam Power. 63 



trials, one carried out by the engiiiemen of the contractors, 

 and the other by those of the purchasers. Both trials to last 

 over a considerable period. In the event of the consumption 

 of coal exceeding that guaranteed by the contract, the con- 

 tractor to pay three-fourths of the capital sum which would 

 have to be paid by the purchasers to provide the additional 

 coal. 



Insurance. — A very considerable saving in the manage- 

 ment of drainage engines might be effected if the Commis- 

 sioners in charge of them were to avail themselves of the 

 advantages to be derived from the regular inspection which is 

 undertaken by the boiler insurance companies. The primary 

 object of these companies is to insure the owners of boilers 

 against the damage arising from explosion, but the greatest 

 advantage derived is from the periodical inspection made by 

 their agents, who furnish reports after each visit as to defects, 

 whether arising from bad setting or from wear or corrosion^ 

 By the timely detection of defects, many explosions are 

 averted, and the reports of the inspectors as to the general 

 condition and management of the engines and boilers should 

 prove a useful check on the manager, and will frequently be 

 found to result in a considerable saving in the amount of coal 

 consumed. 



Engine Drains. — In designing pumping machinery for 

 draining land, care must be taken that the power supplied is 

 adequate to the work to be done. This will depend on the 

 amount of rainfall in the particular district, and the propor- 

 tion of it that has to be lifted in wet seasons. As every ton 

 of water lifted represents the money value of the coal con- 

 sumed in effecting this, it is obviously desirable that all high 

 land water that can drain off by gravitation should be ex- 

 cluded from the drainage district by catchwater drains and 

 banks. The pumping machinery should be adequate to the 

 maximum rainfall of wet years, as it is at such times, when 

 the outfall stream is full, that the benefit will be most felt. 



