ia is now used in this country to denote a quality of tone of an
intensely massive, full and clear character, first realized by Mr.
Hope-Jones, though faintly foreshadowed by Bishop in his Clarabella.
It is produced from pipes of a very large scale, yielding a volume of
foundation tone, accompanied by the minimum of harmonic development.
Even from a purely superficial point of view, the tone of the Tibia
family is most attractive; but, further, its value in welding together
the constituent tones of the organ and coping with modern reed-work is
inestimable." [6]

"The Tibia Plena was invented by Mr. Hope-Jones, and first introduced
by him into the organ at St. John's, Birkenhead, England, about 1887.
It is a wood Flute of very large scale, with the mouth on the narrow
side of the pipe. The block is sunk, and the lip, which is of
considerable thickness, is usually coated with a thin strip of leather
to impart to the tone the requisite smoothness and finish. It is
voiced on any wind pressure from 4-inch upwards. The Tibia Plena is
the most powerful and weighty of all the Tibia tribe of stops. It is,
therefore, invaluable in large instruments. * * * The Tibia Profunda
and Tibia Profundissima are 16-ft. and 33-ft. Pedal extensions of the
Tibia Plena." [7]

"The Tibia Clausa is a wood Gedackt of very large scale (in other
words, a stopped pipe), furnished with leather lips. It was invented
by Mr. Hope-Jones. The tone is powerful and beautifully pure and
liquid. The prevailing fault of the modern Swell organ is, perhaps,
the inadequacy of the Flute work. * * * It was the recognition of this
shortcoming which led to the invention of the Tibia Clausa." [8]

The Tibia Dura is another of Mr. Hope-Jones' inventions. It is an open
wood pipe of peculiar shape, wider at the top than the bottom, and
described by Wedgwood as of "bright, hard, and searching" tone.

The Tibia Minor was invented by Mr. John H. Compton, of Nottingham,
England, one of the most artistic builders in that country. "The Tibia
Minor bears some resemblance to Mr. Hope-Jones' Tibia Clausa, but being
destined more for use on an open wind-chest, differs in some important
respects. The stop is now generally made of wood, though several
specimens have been made of metal. In all cases the upper lip is
leathered. The tone of the Tibia Minor is extraordinarily effective.
In the bass it is round and velvety * * * in the treble the tone
becomes very clear