526 TRANSACTIONS OF THE 



air through the tubes may also be regulated by dampers. The grate bars 

 are placed close together, with narrow air spaces, and the ash-pan and the 

 damper are tightly fitted. The level of the fuel should always be below 

 the air tubes. 



This system is now at work with entire success, on the locomotives of the 

 Great North of Scotland Railway, at Aberdeen, and also, daily, on several 

 of the (among others) engines on the lines of the North London Railway, 

 where, as a metropolitan line, the regulations against smoke nuisance are 

 rigidly enforced. 



It requires a less weight of coal than the engines formerly did of coke, 

 to do the same duly, and thus saves the whole difference in the cost of the 

 fuel. The locomotive engine has been variously cut up in order to suit the 

 views of designers for this smokeless combustion. In the plan before us, 

 the original type of engine, promulgated by Mr. Stephenson, and at this 

 day universally adopted and unsurpassed, is preserved intact; and the 

 locomotive is thus rendered a complete and perfect machine, and entirely 

 meets the great railway necessity of the day, viz., the perfect combustion 

 of coal in railway engines. 



Some members were invited to attend at the Great North of Scotland 

 Railway to examine the facts. The locomotive superintendent, Mr. Cowan, 

 received them on a trip of perfect success. The smoke was most effectually 

 got rid of, by simply opening the valves and acting Mr. Clark's ingenious 

 appai-atus. It was shut off from time to time, when voluminous discharges 

 of smoke testified to its value. Mr. Cowan stated that he had had the plan 

 working for several months, and its action was sure, and was a saving of 

 fuel. 



PROGRESS OP STEAM NAVIGATION AT HULL. 



Hull has been noted, for many generations, for its Greenland and Davis' 

 Straits fishery. At one time over sixty large ships, with each a crew of 

 thirty to forty men, representing a capital of £700,000 sterling. In 1816, 

 63 ships brought home 5,817 tons of oil. In 1820, England and Scotland 

 brought home 18,725 tons of oil. 



Steam vessels are now introduced. The old wooden vessels have been 

 fitted with screws as auxiliary power ; and recently iron vessels. The latter 

 have proved almost a total failure, being bruised, rent among ice, and hard 

 to keep from sinking. And it is a question whether the intense cold of the 

 Arctic is not dangerous, rendering the iron brittle. 



Note. — Messrs. Renwick & Leonard remark, that iron grows stronger as 

 its temperature rises from 32° to a dark heat. 



CHEAP STEAM ENGINES. 



The rapidly extending use of steam engines has already produced serious 

 evils, especially in those for agricultural purposes. They are made by 

 ignorant makers, and cause numerous fatal accidents. They are made 

 extensively in Great Britain for exportation. None should be allowed 

 except such as are made under the superintendence of duly qualified engi- 

 neers. Those otherwise made ought to be broken up. 



