Shanks s Nczu Vertical Steam Engine. 445 



cally performed on the spot where the timber is cut down than they can be 

 when it has to be removed from the forest in the state in which 

 it is felled. The engines shown in the accompanying illustrations 

 are particularly well adapted for the purpose of driving the various de- 

 scriptions of saws here referred to; and since they are, we believe, 

 amongst the cheapest in the market, economy and efficiency (the two 

 main principles aimed at in commercial operations) are by means of 

 them attained in a marked degree. 



The working parts of the engines, which are few and simple, are, as will 

 be seen from the illustrations, enclosed in a strong cast-iron frame, which not 

 only aflFords them the necessary protection, but at the same time secures the 

 most perfect rapidity in working. The boiler is of ample power and 

 strength, and has a fire box sufficiently large for burning wood, thereby 

 economizing the waste and useless timber, and converting it into fuel to 

 keep the engine working at its full power. The engine is fitted with a very 

 sensitive governor, and when required, the larger sizes are fitted with 

 automatic expansion gear, by means of which considerable economy in the 

 consumption of fuel is eflPected, and great steadiness is secured in working 

 the engines, however much the variation of the " load " may be. Both en- 

 gine and boiler rest upon a strong iron base-plafe, which may be either of 

 cast or wrought iron, and which at the same time is used as a tank for sup- 

 plying the boiler with heated water. 



A further proof of the adaptability of these engines for forest work is to 

 be found in the facility with which they may be removed from place to 

 place. The combined engine and boiler, in complete working order, con- 

 sists of four separate and distinct parts, all of which can easily be removed. 

 These are — 



1st. The Boiler. 



2nd. The Cast Iron Frames, containing the working parts of Engine. 



3rd. The Base-plate. 



4th. The Fly-wheel. 



The base-plate has simply to rest on a level foundation, and the boiler and 

 frame containing the engine lifted and secured to it by a few bolts. The 

 steam-pipe connections are then made, and when the fly-wheel has been 

 keyed on to the shaft, the engine is ready for work. A few hours are 

 quite sufficient to complete all these fittings, and no difficulty in adjusting 

 the various parts can possibly be experienced by any one having even a 

 superficial knowledge of mechanics. 



These engines are made from 2 to 12 nominal horse-power. The work- 

 ing pressure in the boilers is GO lbs. per square inch, and at this pressure- 

 the actual or indicated horse-power of the sizes manufactured varies from 

 4 to 28 horse-power. 



Every engine is tested by hydraulic pressure to 200 lbs. per square inch 

 before leaving the works. It will thus be seen that for safety, economy, 

 and easy portability these boilers are not easily surpassed. 



