204 REPORT — 1860. 



On Road Locomotives. By the Earl of Caithness. 



The author referred to what had hitherto been done in this direction, and the 

 importance of attention being given to the construction of them as feeders to the 

 Railway system. He described the arrangement adopted in one which he had had 

 built for his own use, and which was successful. The carriage was exhibited in 

 action, and made several trips in the street under his Lordship's guidance. In the 

 discussion which took place, great stress was laid on the importance of Parliament 

 reducing the turnpike tolls in respect of such carriages, which, in reality, were in 

 no way injurious to the road. 



On Water Meters. By David Chadwick, Assoc. Inst. C.E., Manchester, 



After pointing out the defects in some of the water-meters at present in use, he 

 described the high -pressure piston water-meter of Messrs. Chadwick and Frost, 

 which obviated these defects, and secured the correct measurement of water at all 

 pressures and velocities of discharge, without the use of tumbling -levers, springs, 

 or flexible diaphragms, by a more compact and simple arrangement than any other 

 piston meter; but, without a diagram, it would be impossible to make its con- 

 struction intelligible. 



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A New Mode of obtaining a Blast of very High Temperature in the 

 Manufacture of Iron. By E. Cowper. 



The blast is obtained by an adaptation of the principle of Siemens's regenerative 

 furnaces. A hot blast of a temperature of 1800 3 Fahrenheit can readily be obtained, 

 and this without the destruction of iron tubes- -the Bubstance used in contact with 

 the air being the most refractory fire-brick. This mode of obtaining a blast was 

 in successful operation at Messrs. Cochran's iron-works. The temperature of the 

 blast could be regulated to any required degree. The heat might be obtained with 

 far greater economy than by any method hitherto known. 



The Cylindrical Spiral Boiler. By John Elder. 

 [A communication ordered to be printed entire in the Transactions of the Sections.] 



The object of the construction of this boiler is to obtain a form with all the useful 

 properties of the simple cylindrical high-pressure boiler on shore adapted to steam- 

 ships. 



The following advantages appear to be attained over the ordinary marine boiler, 

 namely : — 



1. A form of boiler capable of carrying higher pressure, and presenting more 

 heating surface, and of a more effective description from a given weight of material. 



2. A boiler capable of being easier cleaned and repaired in both water and fire 

 spaces. 



3. A boiler capable of producing superheated steam to any practical temperature. 



4. A less average specific gravity of water whilst working at sea with the usual 

 amount of feed and blow-off, and a more perfect combustion chamber, and better 

 formation of flue surface. 



5. The pressures being altogether internal, the boiler is not liable to collapse, a 

 danger lately ably demonstrated by Mr. Fairbairn ; and as the diameters of the various 

 cylinders are reduced to the minimum size for permitting the tradesmen to pass 

 through, clean and repair them, the boiler, when formed of ordinary thickness, 

 possesses enormous strength without stays. 



6. The expense of the boiler per square foot of heating surface is about the same 

 as that of the ordinary boiler, and is capable of carrying five times the pressure. 



The general construction. of this boiler is as shown in the accompanying plans, 

 and as follows : — 



There are twenty- four round boilers or tubes, of not less than nineteen inches in 

 diameter, twenty-two of these forming, when bound together, a cylindrical vertical 

 shell ; the twenty-third, a centre boiler concentric to that shell ; and the twenty- 

 fourth, a spiral coil-boiler winding spirally round between the centre boiler and those 



