It may be as well to add that what has been said so far about right and wrong methods of breathing is not by any means mere theory, but that any one can convince himself of the truth of the rules laid down by making a few experiments with the spirometer, an instrument for measuring the breathing power of the chest by indicating on a dial the exact number of cubic inches of air expelled from the lungs. This breathing power will be found to vary according to the way in which the inspiration has been accomplished. In my own case, for instance, the spirometer should register, according to the table of comparative height and breathing power compiled by John Hutchinson, 230 cubic inches. Having suffered from severe attacks of bleeding from the lungs, my maximum with midriff and rib breathing is only 220, but with collar-bone breathing I barely reach 180! During the Summer Session of the Tonic Sol-fa College I carefully tested the breathing capacity of ten students, and found that there was an average excess of midriff and rib breathing over collar-bone breathing to the extent of 25 cubic inches: the least amount of their increased power was 12 cubic inches, and the greatest was 45! I imagine that these figures are more eloquent than any words, and I think it superfluous to make any further comment on them. I am strongly of opinion that breathing exercises, especially in the case of intending public singers, should always be carried on with a spirometer,[D] because that instrument enables us with the greatest accuracy to check results which otherwise can only be guessed at.