Transcriber’s Changes:
[Page vii]: Was ’marvellous’ [In fact, Helen Keller is a marvelous example of the phenomenon common to all human beings]
[Page 46]: Was ’anvles’ [which vary either according to their sides or according to their angles (the equilateral, isosceles, scalene, right angled, obtuse angled, and acute)]
[Page 63]: Added commas [recognized and arranged in order––doh, re, doh, re, mi; doh, re, mi, fah; doh, re, mi, fah, soh, etc. In this way he succeeds in arranging all the]
[Fig. 35 caption]: Was ’si’ [the spaces which remain where the discs are far apart: do-re, re-mi, fah-soh, soh-la, la-ti. The discs for the semitones]