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supported on bushes placed on springs, so as to give a little 

 play both laterally and vertically. At each end of such 

 system of rods is placed either an universal joint, capable of 

 being attached to a similar joint, or a portion of a hollow 

 cone, with a spike in the centre, and teeth or claws on its 

 outer edge; so that two carriages on which the rods are 

 applied being coupled together, such cones on the adjacent 

 set of rods are pushed together, and will be held in contact 

 by the springs, and form a coupling joint, capable of com- 

 municating circular motion from one set of rods to another ; 

 so that such rods will, when the carriages to which they are 

 attached are coupled together, form a continuous line of 

 shafting. Such system of torsion-rods will be extensible or 

 compressible in length, and also yield laterally, according to 

 the motion of the carriages ; but will, when turned on their 

 axes, communicate circular motion. 



This may be more clearly understood by reference to 

 Plate X., Fig, 1, in which A represents the central portion 

 of a shaft revolving in bushes B and B. C and C are 

 universal joints, the construction of which is well known. 

 D D and D D are rods on which the cross-pieces, E and E, 

 slide, and to which are attached the rods F F, sliding into 

 the necks G and G, revolving in the bushes at H and H. 

 On the ends of the rods, F F, are placed hollow cones of 

 metal at I and I, with teeth on the edges. Within the cones 

 are spikes, K K, for the purpose of guiding the cones and 

 teeth together, and which pass into the rod F, made hollow 

 for the purpose. 



In Fig, 2 is shown an enlarged view of two of the cones 

 pushed together and shown as a section, so that the manner 

 in which the spikes are intended to pass into the rods may 

 be more fully seen. On the centre rod, A, {Fig* 1) is placed 

 the grooved pulley, L. MM (Fig* 2) are springs formed 

 of elastic bands of vulcanized India-rubber, which tend to 



