1850.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



71 



Manchester, Sheffield, and Lincolnshire branches and extensions 97 miles. 



Midland extension, 16 miles. 



Nevfcastle and Carlisle branch, 4 miles. • 



North Staffordshire, 51} miles. 



North-Western, 37 miles. 



Reading, Guildford, and Reigate, 45 miles. 



Shrswsbury and Birmingham, 30 miles. 



Shropshire Union, 30 miles. 



South Devon, 2^ miles. 



South-Eastern (North Kent), 25f miles. 



South Staffordshire, 17J miles. 



South Yorkshire, 9 miles. 



WhitehaTen and Furness, 16^ miles. 



York, Newcastle, and Berwick branch, 21} miles. 

 The Scotch lines were — 



Aberdeen, 32 miles. 



Caledonian extensions, 18 miles. 



North British branches, 234 miles. 

 The Irish lines were — 



Cork and Bandon, 9J miles. 



Dublin and Belfast Junction, 22 miles. 



Dundalk and Enniskillen, 18 miles. 



Great Southern and Western extension to Cork, 58| miles. 



Newrv, Warrenpoint, and Rostrevor, G miles. 



RAILWAY TRAFFIC, 18«. 



The gross traffic receipts of railways in the United Kingdom for the year 

 1849 is estimated at 11,013,820^. on 5,161 miles of railway, being an 

 increase of 954,820/. in the receipts over those of the preceding year on 

 4,326 miles, and also an increase of 835 miles of railway in operation. 



Independent of these railways, there are about twenty new lines in opera- 

 tion, of an aggregate length of 445 miles, the traffic returns on which are not 

 published weekly, but may be estimated at 200,000i. for the past year. In 

 addition to these, there are fifteen other lines, of an aggregate length of 

 344 miles, belonging to old railway companies, who do not publish their 

 traffic returns ; but it appears from the returns to the Railway Commis- 

 sioners that the gross receipts on these lines are about 470,000/. per annum. 

 These sums, added to the above, show that the gross traffic receipts on all 

 the railways in the United Kingdom during the past year amounted to 

 11,683,800/.; and the aggregate length of railway open and over which the 

 traffic was carried was 5,950 miles, being at the rate of 1,963/. per mile per 

 annum. 



With regard to the traffic returns of the railways in Great Britain and 

 Ireland, published weekly, they show a progressive increase during the past 

 eight years as follows : — 



£ £ 



1842 4,341,788 



1843 4,842,650 



1844 5,610,980 



1815 6,669,230 



1846 7,689,870 



1847 8,975,671 



1848 10,059,000 



1849 11,013,820 



The annual increase in the receipts has been very considerable, partly 

 arising from the continual development of the traffic on the trunk lines, 

 and partly from the additional receipts derived from the opening of new 

 lines and branches. The increase of traffic in the year 1843 over that of the 

 preceding year amounted to 500,870/.; in the year 1844, to 768,337/.; in 

 1845, to 1,058,340/.; in 1846, to 1,020,650/.'; in 1847, to 1,285,780/. ; 

 in 1848, to 1,083,335/. ; and in 1849, the increase over the preceding year 

 amounted to 954,810/. 



At the end of the year 1842, 1,510 miles were open to the public ; during 

 the next year an additional length of 56 miles of new railway was opened 

 for traffic ; in 1844 a further length of 194 miles was opened ; in 1845, 263 

 miles; in 1846, 593 miles ; in 1847, 839 miles ; in 1848, 975 miles; and in 

 1849, a further length of 834 miles, making at the end of the year a total 

 length of 5,161 miles in operation. 



The average traffic receipts per mile show the effect of opening within the 

 past three years so many miles of branch and competing lines of railway. 

 During the year 1842, the gross traffic receipts averaged 3,1 13/. per mile; in 

 1843,3,085/.; in 1844,3,278/.; in 1845,3,469/.; in 1846,3,305/.; in 1847, 

 2,870/.; in 1848, 2,536/.; and in 1849, 2,302/. per mile. This shows a 

 gradual falling off in the average traffic per mile during three years of more 

 than 30 per cent., and there seems every probability of its continuance, so 

 long as the present erroneous system is pursued in constructing unproduc- 

 tive extensions and unnecessary branches. The reduction in the receipts 

 per mile would be a matter of no great consequence, provided the average 

 cost of constructing the railways was proportionahly reduced, say in the same 

 ratio of the traffic per mile, from 33,000/. to 23,000/. per mile, and so on in 

 like manner with every additional mile added to the system. Unfortunately 

 this is not the case, as the following will show :— In 1842 the cost of the 

 railways in operation averaged 34,690/. per mile; in 1843, 36,360/.; in 

 1844,35,670/.; in 1845, 35,070/.; in 1846, 31,860/.; in 1847, 31,700/.; 

 in 1848, 34,234/., and in 1849, 35,214/. On a comparison of the average 

 cost per mile in 1845 of 35,070/., when there were only 2,040 miles of rail- 



way open, with the average cost fin 1849, of 35,214/., when there were 

 5,160 miles open, it shows that an increase in the cost per mile has taken 

 place, notwithstanding that 3,120 miles of additional railways and branch 

 railways have been constructed. 



The increase instead of a decrease in the average cost per mile is a most 

 alarming feature in railway statistics, because it shows clearly that the con- 

 tinual additions to the capital accounts of the old and completed lines of 

 railway far outweigh all the professed advantages of constructing thousands 

 of miles of new railways and branches at considerably less cost than the 

 average expenditure per mile on the old trunk lines. It was stated both in 

 and out of Parliament that the new lines authorised in the 1844 and succeed, 

 ing sessions would not exceed 25,000/. per mile, and that a considerable 

 portion of them would not cost above 18,000/. per mile. Some have been 

 constructed within the estimate, and others have exceeded it. The serious 

 evils arising from the improper practice of adding large sums every half-year 

 to the capital accounts of old railways must be remedied in future by 

 closing at once their capital accounts, and also the capital accounts of every 

 new railway, before the end of two years after the opening of the line; 

 otherwise there can be no foundation for confidence in either railway 

 property or railway management. 



The capital expended on railways, the (traffic returns of which are pub- 

 lished every week, amounted in Julv 1842, to 62,380,000/.; in 1843, to 

 57,635,000/.; in 1844, to 63,489,000/'.; in 1845, to 71,648,000/.; in 1846, 

 to 83,165,000/.; in 1847, to 109,528,000/. ; in 1848, to 148,200,000/. ; and 

 in July 1849, to 181,000,000/. The gross traffic returns per cent, on the 

 capital expended amounted, in 1842, to 8-29 per cent. ; in 1843, to 8 42 j in 

 1814, to 8'84 ; in 1845, to 9-30; in 1846, to 9-25; in 1847, to 8-20 ; in 

 1848, to 6-78 ; and in 1849, to 6-13 per cent. This gradual decrease in the 

 revenue, with a greatly increased capital and mileage, shows the absolute 

 necessity of closing the capital accounts. 



The expenditure on the new and old lines, the traffic returns of which are 

 not published weekly, amounts to about 16,000,000/., that is, 9,000,000/. on 

 the former, and 7,000,000/. on the latter, making, with the 181,000,000/., a 

 total of 197,000,000/. expended on 5,950 miles of railway, being an average 

 cost of 33,110/. per mile. 



PROTECTION OF IRON FROM OXIDATION. 



At the Exposition at Paris in 1849, there were exhibited numerous articles 

 manufactured in iron, covered with a kind of transparent vitreous coating, 

 completely spread over the surface of the metal, like a varnish, and capable 

 of affording a perfect protection against the action of the air, or any other 

 oxidizing agent. This appears to be an invention susceptible of many useful 

 applications; for, whether the iron be in the state of a rolled plate or bar, 

 or drawn into tubes; whether it he cast into water pipes or into articles of 

 the most elaborate form and design, as vases, and other ornamental works, 

 it can be equally well endowed with this protective coating — it is also a 

 matter of indifference whether the article be made of forge or cast-iron. The 

 following is stated to be the process employed in imparting to the iron the 

 vitreous surface : — Firstly, the object, whatever its shape may be, is thoroughly 

 cleansed by dilute acid, which serves to remove, from the metallic surface, 

 grease, dirt, and every trace of oxide; this is important, for, if any foreign 

 matter remain upon tlie surface, the perfect adherence of the fused glass will 

 be effectually prevented, when that part of the operation is reached. After 

 the action of the dilute acid, the work is to be well washed and then dried ; 

 when perfectly dry, it must be brushed over with a tolerably strong solution 

 of gum-arabic, which may be applied by means of a camel-hair brush. Over 

 the whole extent of the gummed surface, powdered glass, of a peculiar kind, 

 is then sifted, and care must be taken to cover every part of the surface with 

 this powder, otherwise the vitreous coating will be imperfect when the 

 operations are completed. When thus prepared, the work is introduced into 

 a furnace or retort, heated to 100° or 150° centigrade; (212° to 302° F.} 

 and, when thoroughly dry, it is removed to another furnace, where it is 

 brought to a cherry-red heat; the vitreous matter, which adhered to the 

 gummed surface of the metal, now undergoes fusion — the progress of this 

 stage of the process is ascertained by looking through a small opening (con- 

 trived for this purpose) into the heated chamber. When the fusion is com- 

 plete, and the glass seems to have flowed over the whole of the surface, the 

 article is removed from the furnace and placed in a close chamber, from 

 which the air is entirely excluded — here it is kept until it has cooled down 

 to the temperature of the atmosphere. The vitreous compound, applied to 

 the surface of the metal, consist of the following substances ; — Powdered 

 flint glass, 130 parts ; carbonate of soda, 20i parts ; boracic acid, 12 parts. 

 These must be melted together in a " glass pot," and a fusible glass will be 

 the result ; when cold, this must be pounded with care, so that it may be 

 reduced to a powder, sufficiently fine to pass through a silk sieve. When 

 thus prepared, it is ready to be applied to the surface of the iron, according 

 to the method described above. If, after the .first process, the coating of 

 vitrified matter on the metal should prove not to be quite perfect, the mani- 

 pulation must be repeated, a second coat of powdered glass being applied in 

 the same manner as the first. It is necessary that the vitreous matter which 

 forms the coating should be quite free from foreign matter, for if the object to 

 be coated be oxidized or greasy, the coating of glass will not adhere, and 

 the result of the operation will be, consequently, very imperfect.J ___^ 



