264 APPLIED SCIENCE 



avoids grinding at rapid curves, and the adhesion given by one 

 wheel will be ample in a dry country, such as that where this 

 locomotive is to work. The arrangement of the gearing, E and 

 F, is obvious. It allows the locomotive to lie fore and aft instead 

 of across the line, and this design has some advantages in the 

 adjustment of the weights. The surface of the gripping wheels 

 are arranged like an upright V, so as to hold on under the line. 

 This makes it very difficult for the wheels to leave the line, both 

 because of their absolute hold, and because the inclination of the 

 V is such as to favour the action of gravitation in overcoming the 

 friction of the grip, instead of opposing it, as in the inverted V. 

 Another feature of this machine is the arm pivoted at P, and 

 carrying the leading wheel, which is again pivoted at M in the 

 arm, as in the case of the trucks. The construction allows the 

 locomotive to traverse curves of six-feet radius a very remark- 

 able result. The full-sized locomotive has only just been com- 

 pleted, and run on three spans at Messrs. Easton and Anderson's. 

 So far as I am able to judge from the trial, it is likely to be a 

 complete success. It will be immediately shipped for its desti- 

 nation, so that its performance cannot be more fully tested in 

 this country. The following particulars will show that it is 

 much more powerful than the belt locomotive, but it is con- 

 siderably heavier : Wheel base, 2 ft. 6 in. ; weight, about 3 cwt. 

 14 Ibs. ; 15 revolutions of motor per revolution of driving-wheels ; 

 diameter of driving-wheels, 10 in. ; 33'3 in. Ib. per 100 Ibs. pull 

 at rail ; 504 revolutions of motor per minute for one mile per 

 hour. 1 am in doubt at this moment whether to adopt the belt 

 locomotive or the spur-wheel locomotive for the next example ; 

 it is simply a question of cost, weight, and durability. Either 

 will do the work. In all the arrangements it is essential that 

 the second bearing-wheel at M (Fig. 13, p. 263) should lead, not 

 follow, the drivers in regular work. The reverse arrangement 

 lets the rope lead on at an angle with the plane of the roller, 

 causing an injurious grinding action. Details of couplings have 

 been well worked out, but space fails for their description. 



As general features of the train running on the line, I may 

 mention that the deflection of the rod within reasonable limits 

 has very small influence on the resistance. When the deflection 

 on a 50-foot span was about 2 -4 feet, the resistance for a train 

 of trucks, weighing in all 1 ,260 Ibs., was 22 Ibs. ; and no sensible 



