2, looks as though composed of a number of segments, gradually decreasing in size from base to tip like the joints of a telescope, instead of tapering gradually and evenly from one extremity to the other.
An amount p 2 which seems small but which would be quite sufficient to destroy one or more of the joints if provision were not made to prevent damage.
There are several joints in general use for the best class of work which are formed with the aid of india-rubber rings or collars, any expansion being divided amongst the whole number of joints.
In this several microphonic joints were employed.
Bridges Adams, the intention being by " fishing " the joints to convert the rails into continuous beams. In the original design two chairs were placed, one under each rail, a few inches apart, as in fig.