1871J 



on Psychic Force. 



485 



grooved frame carrying a flat box similar to the dark box of 

 a photographic camera. This box is made to travel by 

 clock-work horizontally in front of the moving index, and 

 it contains a sheet of plate-glass which has been smoked 

 over a flame. The projecting steel point impresses a mark 

 on this smoked surface. If the balance is at rest, and the 

 clock set going, the result is a perfectly straight horizontal 

 line. If the clock is stopped and weights are placed on the 



Fig. 



V^^ 



end b of the board, the result is a vertical line, whose 

 length depends on the weight applied. If, whilst the clock 

 draws the plate along, the weight of the board (or the ten- 

 sion on the balance) varies, the result is a curved line, from 

 which the tension in grains at any moment during the con- 

 tinuance of the experiments can be calculated. 



The instrument was capable of registering a diminution 

 of the force of gravitation as well as an increase ; registra- 

 tions of such a diminution were frequently obtained. To 

 avoid complication, however, I will only here refer to results 

 in which an increase of gravitation was experienced. 



The end b of the board being supported by the spring 

 balance, the end a is supported on a wooden strip, f, 

 screwed across its lower side and cut to a knife edge (see 

 Fig. 4). This fulcrum rests on a firm and heavy wooden 



