206 REPORT— 1841. 



of the air acting against the foremost carriage has a greater effect in throw- 

 ing the succeeding carriages out of square than it would have if the train 

 were preceded by the engine and tender. 



4. In what manner the resistance would be modified by increasing the 

 length and weight of the train. 



These questions have severally arisen out of objections urged against the 

 experiments detailed in the former part of this Report, and against the vali- 

 dity of the consequences therein deduced from them, by Mr. I. K. Brunei, 

 the engineer of the Great Western Railway, in a report addi-essed to the 

 directors of that company. 



Although, from the general experience of the writer of this Report and of 

 the other members of the Committee, it appeared that none of these various 

 objections had much weight, it was considered right to bring them to the 

 immediate test of experiment. 



It was first objected, " That the circumstances under which the experiments 

 " were performed were not really, though they were apparently, similar to 

 " those of any ordinary train in motion ; that the carriages in these experi- 

 " ments were sent with the square end foremost to meet and receive the full 

 " resistance due to their surface, which is totally different from the case in 

 " which the engine precedes them." The engine in front, it was stated, would 

 act as a cut-air or bow, and thus destroy or diminish the resistance produced 

 by the flat front of the carriage moving foremost. 



In order to ascertain the force of this objection, the following experiment 

 was made. 



An engine called the "Fury" was reduced as nearly as possible to the 

 condition of an ordinary carriage, by detaching from the axles and removing 

 from the engine the connecting rods, pistons, working gear, and every mo- 

 ving part which could produce any mechanical resistance different from that 

 to which an ordinary coach would be subject. Two coaches were also pro- 

 cured, and so loaded as to be exactly equal in weight with the engine and 

 tender. 



The engine and tender were then placed at the summit of the Sutton in- 

 clined plane on the Liverpool and Manchester Railway, which falls 1 in 89, 

 for about a mile and a half, and were allowed to descend the plane by their 

 gravity ; the time of passing a succession of stakes dividing the plane into 

 spaces of 110 yards, was noted. 



The two coaches were next placed at the summit of the plane, and allowed 

 in like manner to descend, and the circumstances of their descent observed 

 in the same way. 



Sutton Incline Plane. — Is laid Avith 60 lbs. rails, 3 feet bearings, on stone 

 blocks: road has been recently relaid : posts are placed 110 yards, or one 

 sixteenth of a mile apart : descent from No. to No. 1 1 post is 3*63 feet per 

 110 yards =1 in 90*9 : gravitating force is therefore 24*64 lbs. per ton : de- 

 scent from No. 11 to No. 20 post is 3'71 feet per 110 yards = 1 in 88'5; gra- 

 vitating force is therefore 25*31 lbs. per ton. 



Whiston Incline Plane. — Was laid with 50 lbs. rails, 3 feet bearings, on 

 stone blocks, about three years since: posts placed 110 yards, or one six- 

 teenth of a mile apart : descent 1 in 96 : gravitating force is therefore 23*33 

 lbs. per ton. A section of these planes is given in fig. 1. Plate I. A breeze 

 from W.N.W. : a drizzling rain : rails quite wet, and in good order for 

 travelling. 



The details of these two experiments were as follows : — 



