PROFESSOR K. PEARSON AND IMISS A. LEE ON THR DISTRIBUTION 
The barometer devised for this purpose is illustrated in figs, A and B. Fig, A is 
a diagrammatic plan of the instrument ; fig. B is from a photograph of a rough model 
made by the Cambridge Instrument Company. The barometer must be an aneroid, 
or some instrument woi’king with a needle over a horizontal dial. This needle is 
removed, and replaced by a light V-shaped gutter of paper or metal-foil, sloping 
downwards from the centre to the periphery of the dial. This gutter needle is indi¬ 
cated by a, b in fig. A. Its outer extremity projects slightly beyond the dial over 
the tojis of a series of small vertical tubes, c, c, c, which are equally spaced and 
separated by small wedge-shaped divisions, running along the lines d, d, d. If we 
suppose a ball to be dropped into the gutter at o, it will roll down to h. drop over, 
