Nature's Teachings: Human Invention Anticipated by Nature

by J. G. Wood

The upper left-hand figure represents the “Buffer,” by which the carriages of railway trains are prevented from jarring against each other.

Perhaps some of my readers may be old enough to remember the days of the old railway carriages that were connected by short chains, and furnished with buffers that were merely padded. As the train started a separate jerk was given to every carriage by the tightening of the chains, and, as it stopped, all the carriages bumped against each other in a most unpleasant manner. Now, however, the buffers are furnished with powerful springs, and are pressed strongly against each other by means of screw-bolts, so that they form one continuous line.

In fact—and here is another analogy between Art and Nature—a train, when properly made up, bears a close resemblance to a human spine, the carriages being analogous to the vertebræ, and the spring buffers to the elastic cartilages between the vertebræ.

Nowadays, owing to this arrangement, the whole train moves together, and can be started and stopped so gently that the passengers are hardly aware of movement or stoppage. For example, one of my friends was in a train which came into collision with some obstacle. The carriages in front were dashed to pieces, and several of the passengers killed. His carriage, however, which was nearly at the end of the train, and had the benefit of all the springs, was hardly shaken, and the inmates did not know for some little time that an accident had occurred.

Below the buffer is a Wheel Spring, made exactly on the same principle, but set perpendicularly instead of horizontally.

The two figures beneath the wheel spring represent an object very familiar to us, namely, a Spring Solitaire, one figure showing it as open, and the other as closed. In this article the clasp is held in its place by a spring, and is only released by pressure.

Below the solitaire is a very prosaic application of the Spiral Spring, namely, that by which a house-bell is kept in vibration after the force of the pull has ceased, and which renders the bell, as Dickens happily remarks, so greedy to ring after it has been pulled.

I made and employed a spring of a similar character in closing the door of my parrot’s cage. Polly is a wonderfully clever bird, and a capital talker. First, she had a cage with upright bars, two of which could be slid upwards by way of a door. She soon found out the trick of the bars, and used to escape, carefully replacing the bars afterwards.

When she was transferred to a metal cage, she discovered that the door slid upwards, and began at her old tricks. So I took a piece of galvanised iron wire, coiled it into a spiral spring, fastened one end to the upper part of the door, and the other by a hook to a staple at the bottom of the cage. Consequently, when Polly lifted the door, and loosened her grip for a fresh hold, the door closed itself again. So, after awhile, Polly gave up the door, and now never tries to open it.