1867. J Engineering —Civil and Mechanical. 105 



able direct gain in the strength of boilers, and, probably, upon the 

 disappearance of" furrowing/' which generally appears to be localized 

 in the near neighbourhood of a seam of rivets. A few years ago 

 the safe limit of steam pressure in a locomotive boiler was considered 

 to be but 50 lbs., and now many engines on the lines about London 

 are worked at 160 lbs. Great advantage would follow the use of a 

 higher pressure, as it would enable the steam to be worked more 

 expansively, and this may probably soon be accomplished, since a 

 small steel boiler has recently been made for Mr. Salt, of Saltaire, 

 which has not one rivet in it ; all the joints are welded, and it has 

 been proved to 300 lbs., and is intended to work at 250 lbs. There 

 is a growing tendency greatly to increase the weight of locomotives, 

 as there is a constant demand for engines of greater and greater 

 tractive power, and Mr. Fairlie is building one of 72 tons weight 

 for the Paris Exhibition. By his plan of double bogies of coupled 

 wheels, each driven by a separate pair of cylinders, he not only dis- 

 tributes the weight of the engine upon eight or twelve points, as 

 required, but he obtains great ease of working round very short 

 curves, the governing wheel base being that only of each bogie. On 

 the Northern Railway of France four- cylinder engines have been 

 in use since 1863, and it has been proved, by experience, that the 

 cost of maintenance of a four-cylinder locomotive is less than that 

 of ordinary engines in proportion to the power developed. 



Two very useful little machines have lately been designed by 

 Mr. R. Angus, Locomotive Superintendent, North Staffordshire 

 Railway, the one being for the purpose of planing the valve-faces, 

 and the other for boring the cylinders, of locomotives whilst they 

 remain fixed on the engine, thus saving a large amount of manual 

 labour and time. 



Delegates have, during the past quarter, arrived in London from 

 Nova Scotia, New Brunswick, and Canada, for the purpose of 

 arranging for the commencement of the Intercolonial Railway to 

 complete the line of communication between Halifax and Quebec. 

 By the shortest of the three routes that have been surveyed, the 

 distance is 588 miles, of which 192 miles are already occupied by 

 railways, leaving 396 miles to be constructed to complete the 

 communication. The estimated cost of construction is 8,300?. per 

 mile, or 3,286,800Z. for the whole length, and it is understood that 

 an Imperial guarantee of the interest upon 3,000,000?. has been 

 conceded for the line. 



A short line of railway has recently been opened in one of the 

 most hilly outskirts of Paris, namely from Enghien to Montmo- 

 rency. The length of this new line is less than two miles, and its 

 peculiarity is that it consists almost entirely of curves of 300 metres 

 radius, and inclines of 0*045, with the exception of a level bit of 

 150 metres at either end. The completion of the Chemin de Fer 



