664 PROCEEDINGS OF SECTION J. 



10.— SOME METHODS OF EDUCATION AS PRACTISED 

 IN THE PRIMARY PUBLIC SCHOOUS OF SOUTH 

 AUSTRALIA. 



By M. M. 3IAUGHAK 



.l._SOME PREDILECTIONS OF PICTORIAL AND 

 DECORATIVE ART. 



Bij H. P. GILL. 



(^WlTHDllAWN.) 



-O-^Jl-O- 



12.— NOTES OF PSYCHOPHYSICAL EXPERIMENTS. 



B>i E. F. J. LOVE, M.A., Fellow and Rector of Queen'' s College, Melbourne, 

 Assistant Lecturer arid Demonstrator in Natural Philosophy to the University . 



The object of this pa23er is to detail the results, so far as they 

 are of interest from the psychological point of view, of certain 

 experiments originally carried out with a quite different object. 



1st. The determination of the limit of comparability in the illumi- 

 nation of two bright surfaces viewed simultaneously. 



Several methods were employed. In the first a circular disc of 

 opal glass was rotated at a very high speed by means of an electro- 

 motor. A narrow radial black mark, about an inch long, being 

 made by one observer on some part of the disc, it was set in 

 rotation ; and the second observer, previously outside the labora- 

 tory, was called in and requested to state whether the disc showed 

 a grey ring, and, if so, to define its position by reference to a 

 foot rule placed opposite the disc. The narrowest line which gave 

 a perceptible grey ring had a breadth of about 1/1 80th part of 

 the circumference of the ring ; hence the smallest difference of 

 intensity perceived in this way was the 1/1 80th part of the 

 intensity of the light diffused from the opal glass. The experiment 

 was conducted in full daylight. 



Other experiments, conducted with artificial light, using ordinary 

 photometric methods, gave a lower value, about 1 per cent, being 

 the smallest perceptible difference. It was found that with colored 

 lights even this was considerably reduced. Furthermore, the 

 results dejDended considerably on the intensity of the light em- 



