Page 56 – “sea-side” changed to “seaside” (At the seaside) Page 56 – “sea-side” changed to “seaside” (study of seaside pools) Page 136 – “sound ray” changed to “sound-ray” in Fig. 51 caption Page 145 – “limelight” changed to “lime-light” (lime-light lantern) Page 156 – “over-tones” changed to “overtones” (accompanied by the harmonics or overtones) Page 162 – “key-board” changed to “keyboard” (keyboard of a piano) Page 176 – “aërial” changed to “aerial” (stationary aerial oscillation) Page 177 – “horse-hair” changed to “horsehair” (bow made of horsehair) Page 274 - “Full Stop — — — — — —” changed to “Full Stop — ——— — ——— — ———” ———— Footnotes have been re-indexed using numbers and placed before the Index. ———— Large bracketing is not available to surround built-up fractions in displayed equations and expressions so ordinary bracketing and the solidus (/) is used to represent them instead. Thus the built-up x + 1 fraction ————— is rendered in this text in the conventional manner 2 as (x + 1)/2. If the sin of that expression is required it would be rendered unambiguously as sin((x + 1)/2). For consistency this also means that a simple sin function that would normally be displayed as ‘sin x’ will instead be rendered as ‘sin(x)’. A large radical (√) symbol is not available either so in order to make the radicand expression unambiguous a similar approach to the above is used. x + 1 Thus the square root of the fraction ————— is rendered in this text as 2 √((x + 1)/2). Again this means that, for consistency, the simple square root of, say, the natural number 5, which would normally be displayed as ‘√5’ will instead be rendered as ‘√(5)’. In other expressions and equations some additional bracketing may have been added to make the meaning clear and unambiguous or consistent with bracketing as used in immediately surrounding equations and expressions.