246 MEMORIES OF MY LIFE 



fee, already described, for admission. That just 

 defrayed the working expenses. 



It is by no means easy to select suitable instru- 

 ments for such a purpose. They must be strong, 

 easily legible, and very simple, the stupidity and 

 wrong-headedness of many men and women being 

 so great as to be scarcely credible. I used at first 

 the instrument commonly employed for testing the 

 force of a blow. It was a stout deal rod running 



o 



freely in a tube, with a buffer at one end to be hit 

 with the fist and pressing against a spring at the 

 other. An index was pushed by the rod as far as it 

 entered the tube in opposition to the spring. I found 

 no difficulty whatever in testing myself with it, but 

 before long a man had punched it so much on one 

 side, instead of hitting straight out, that he broke 

 the stout deal rod. It was replaced by an oaken 

 one, but this too was broken, and some wrists were 

 sprained. 



I afterwards contrived, and used in a subsequent 

 Laboratory, a pretty arrangement that gave the 

 swiftness, though not the force of the blow, with 

 absolute safety, and which could be used for other 

 limbs than the arm. The hand held a thread, the 

 other end of which was tied to an elastic band, capable 

 of pulling it back faster than any human hand could 

 follow; so the hand always retarded its movement. Its 

 speed was shown by the height to which a bead, 

 actuated by the string (it is needless to explain details), 

 was tossed up in front of a scale. This never failed, 

 and was perfectly easy to manipulate. 



The observations made in this Laboratory were of 

 great use to me later on v Four hundred complete 



