Читать книгу The Recent Revolution in Organ Building - George Laing Miller - Страница 16

Table of Contents

[1] The invention of the pneumatic lever has been claimed for Mr. Hamilton, of Edinburgh, Scotland. It is, however, generally credited to Barker and known as the "Barker pneumatic lever." (See also note about Joseph Booth, page 129.)

[2] Barker was also associated with Péschard, who in 1864 patented jointly with him the electro-pneumatic action. (See page 37.)

[3] The pressure of the wind supplied by the old horizontal bellows is regulated by the weights placed on top. The amount of this pressure is measured by a wind-gauge or anemometer invented by Christian Förmer about 1677. It is a bent glass tube, double U shaped, into which a little water is poured. On placing one end of it fitted with a socket into one of the holes in the wind-chest (in place of a pipe) and admitting the wind from the bellows the water is forced up the tube, and the difference between the level of the surface of the water in the two legs of the tube is measured in inches. Thus, we always talk of the pressure of wind in an organ as being so many inches.

[4] The organ in Great Homer Street Wesleyan Chapel, Liverpool, England, had manuals extending down to CCC. It was built for a man who could not play the pedals and thus obtained 16 ft. tone from the keys. The old gallery organ in Trinity Church, New York, also has this compass.

[5] Tenor C is the lowest note of the tenor voice or the tenor violin (viola). It is one octave from the bottom note of a modern organ keyboard, which is called CC. The lowest note of the pedal-board is CCC. Counting from the bottom upwards on the manual we have, therefore, CC (double C), C (tenor C), c (middle C), c¹ (treble C), c² (C in alt) and c³ (C in altissimo). This is the highest note on the keyboard of 61 keys. According to the modern nomenclature of the pianoforte keyboard this note is c⁴, and is frequently so stated erroneously in organ specifications.

GG is four notes below CC, the break in the scale coming between GG and FFF. Tenor C is an important note to remember. Here is where the cheap builder came in again. He cut his stops short at tenor C, trusting to the pedal pipes to cover the deficiency.