8a».] 



THE CIVIL ENGIKEER AND ARCHITECT'S JOURNAL. 



as 



3755lbs. ; class second, 2468U)s. ; class third, 2;)37lbs. -, da^s fourth, 

 20901bs." 



We have examined those calculations but have not found one of 

 llieni correct. 



Class I. 



3'141G X -54 = Ifi9.G4, circumference of wheel, 



14^ X '7854 X 2 = 307-870, area of 2 pistons. 



2x16 = .32 inches, length of double stroke, 



.S07-876 X 6i-~ = 19919-C2ft9C, force applied on the pistons, 



- — =:5'301, ratio of the velocity of wheel and pistun, 



19919'62896 „,., ,,,, ,. •, , ., • 



— ■ = 37o7'711bs. power applied to make the engine 



^■'^"' advance. 



Class 2. 

 12' X '7854 X 2 = 220-195, area of 2 pistons, 

 226-195 X 64-7= 11634-816, foice applied on the pistons, 

 .3-J416 X 60 



— -— — =:5'S90, ratio of the velocitv of the wheel and piston 



2 X 16 r . 



14634-816 _„,.,,, ,. , , , .J 



— r^gqK 24841l)s. power applied to make the engine advance. 



Class a. 

 11- X -7854 X 2 = 190-0668, area of 2 pistons, 

 190-0668 X 64-7 = 12297-32196, force applied on the pistons. 

 8-1416 X 60 _ 

 — g-J-yg 5-236, ratio of rhe velocity of wheel and piston, 



12297-32196 _OQ,.in 



j^^ _'.H8lbs. power applied to make the eng 1114 advance 



C'LA^s 4. 

 ll'' X '7854 X 2 = 1900668, area of 2 pistons, 

 190-0668 X 64-7 =12297-32196, force applied on the pistons. 



.^-1416 X 60 



— — =5-890, ratio of the velocity of wheel and piston 



2 X 16 ' ' 



12297-32196 „„„,,, ... , , 



— -^-^ = 20871bs. power applied to make the engine advance. 



" The gradients .also, on the regulalion of which so much depends, 

 both in respect to the original cost and the ultimate v.alue of the rail- 

 way to the country, have been carefully gone over hv one of tlie com- 

 missioners, in conjunction with the engineer, and in consequence 

 several material .alterations were made, which have much lessened the 

 amount of the original estimate, without aflecting ; in an important 

 manner, either the rapidity of intercoiirse or tlie commercial advantage" 

 — Page ;j7, Railw.iy Report. ° 



In the September number of our journal for 18;JS, we jirinted a list 

 of sixty-live errors found in tlie gradients, .and upon a more full 

 ex.amination there will be found .at least fioiu forty to sixty more ■ this 

 clearly shows that very little care or attention was bestowed b'v the 

 commissioner and engineer who had ex.nnined and "one over the 

 gr.adients; indeed, the very numerous errors found in the gradients are 

 destructive to the character and accuracy of the Railway Report and 

 Sections, although ' 



" My Lords had full confidence, from the character of the gentlemen 

 appointed to form the commission, tliat their inrpiiries w.uild be con- 

 ducted in a satisfactory manner." 



We consider an alteration in gradients from one in330, to one in 180 

 as most important.bothas to rapidity of intercourse, and also as to com' 

 mercial advantage, .although the raihv.ay commissioners do not think so 



llie same force of traction which is required to draw llHt tons un .1 

 rise of one in 330, would draw on the level 195 tons. 



Engine 



tons, 

 100 X 

 1 00X22 40 



330 

 12x2240 



lbs. lbs. 

 8 = 800 



= 679 



330 



— = 81 



(if"= 195 tons.) 



1560 Total resistance not including the 

 friction of tlie engine. 



The s.ame force of traction which is required to draw 100 tons up a 

 rise of one in 180 would diaw on the level 274 tons. 



LBS. 



100X8Ibs. = SOOlbs. friction at 8lbs. per ton. * . .800 

 100x2240 ,, ,, . _ 



— ^ = 12441bs. gravity of the 100 tons (reduced to 



lbs.) on a plane inclined in the ratio of — L 



180 1244 

 122X224() 

 -■ I'gQ-- = 149lbs.gravityof the engine on the same plane 149 



Total resistance not including the friction of the engine 2193 



/■2193 .,-,. N 

 (- = 274 tons, j 



This shows the difference between the rise of one in aSO and one in 

 180. 



The load, tender, and engine, taken at 1 00 tons, and running at the rate 

 of 20 miles per hour on the level plane, will, on ascending a slope of one 

 in 330, run only .at a rate of 14.20 miles per hour, and ascending a slope 

 of one in 180. will run at a rate of 1 1-43 miles per hour. 



An engine capable of evaporating 48 cubic feet of water per hour wil 

 draw on the level plane 88-32 tons, at the rate of 20 miles per hour 



up, 1 in .000 — 51-96 tons, 



400 — 46-49 tons, 



... 300 — 39-09 tons, 



... 200 — 28-44 tons, 



100 — 11-97 tons. 



\Vood< on Railways. P.age 57S. 



Looking at the levels whicli the surface ol Ireland presents, we differ 

 entirely with tlie Irish Railw.ay Commissioners, as to adopting 1 in 180 

 as the characteristic gradient for the main trunk lines proposed to be 

 laid out Ihrongb that country; and we object still more so to 1 in a 100 

 for the great m.ain line of railway laid nut from Dulilin to Cork, which 

 .appears by the Railway Commissioners' sections to be the characteristic 

 gradient of that line, because an engine running up such a slope can 

 only draw about oue-eiglith of the load that it can on the level plane ; 

 and running up 1 in 180 less than one third of tlie lo.ad it can draw- 

 on the horizontal plane. We are, therefore, thoroughly convinced that 

 the Irish Raihv.ay Commissioners have notsufficientiy studied this most 

 important element in raihv.ay engineering ; or lips their limited know- 

 ledge of such a subject precluded them from being able to comprehend 

 the vital advantages arising from tlie adoption of good gr.adients, even 

 .although attended with some expense in cutting and embanking? 



In our journal for last September, we forcibly alluded to , the very 

 great injustice of not giving railway communication to the centre of 

 Ireland, and also to the fertile province of Connauglit; we stated our 

 reasons why that province ougl-.t to participate in railway intercom- 

 munication, as well as the other provinces of Ireland. In the same 

 niimber of the journal we stated our reasons fully against the line of 

 railway projected by the commissioners from Dublin to Armagh, and 

 we particularly observed that it ran parallel with the coast railway 

 for nearly one hundred miles, and that it could not be possible that two 

 such lines could exist, as one or other of tnem would be a total 

 failure. Having witli some attention sndied the commissioners' inland 

 lines of railway from Dublin to Armagh and Enniskillen, we think 

 that those projects recommended by them are extremely injudiciously 

 planned ; because, if an inland main trunk line was to be laid out 

 from Dublin to Armagh, with a branch line to Enniskillen, and were it 

 determined upon that the important tr.iding town of Drogheda should 

 be excluded from railway communication with the capital, then lines 

 of railway might h.ave been chosen which would have united Dublin 

 to Armagh and Enniskillen, with a saving of twenty-six miles of 

 railway, which would be a great advantage as regards economy, not 

 only in the first construction of these lines, but also in the working of 

 them afterwards. 



The system of main lines of railway, which h.ive been proposed to 

 be carried into effect by the various companies through the south of 

 Ireland, possess superior advantages in connecting the various large 

 cities together, than those recommended by the Iri.sh Railway Com- 

 missioners. The lines proposed by the companies being much more 

 expensive, and laying open a wider, a more populous, and a richer 

 extent of Ireland's surface, with less mileage and better levels than the 

 Irish railway commissioners' main lines appear to do. This fact has 

 been established by the calculations already given ; and by examining 

 the Irish commissioners' index map of the'proposed railways, there is 

 to be seen a small triangular portion of country lying between Cahir 

 and Hollycross which is completely encompassed by railways, amount- 

 ing to more than 40 miles in length, and which cannot fail to strike 

 every engineer, who will take the trouble to examine the proposed 



