Trumpet
2 of the 6 encyclopedias on this shelf carry an entry for Trumpet. Both are reproduced below, so you can see where they agree and where they differ.
Collier's New Encyclopedia (1921)
in music, a metal wind instrument of bright and penetrating tone, formed of a single tube of brass or silver, curved into a convenient shape, with a mouthpiece at one end, the other having a bell. Its part is usually written in the key of c with the treble clef, though by means of crooks or lengthening pieces the sounds produced may be in various keys. The trumpet required for a piece is indicated at the commencement, as trumpet in B, C, D flat, E, F, or G. The modern orchestral or slide trumpet consists of a tube 66% inches in length and three-eighths of an inch in diameter. It is twice turned or curved, thus forming three lengths; the first and third lying close together, and the second about two inches apart. The slide is connected with the second curve. It is a double tube, five inches in length on each side, by which the length of the whole instrument can be extended. Trumpets with pistons or valves capable of producing every chromatic sound within their compass are sometimes used, but the tone is by no means to be compared with the true trumpet tone. Also, a stop of an organ having reed pipes tuned in unison with the open diapason. The octave trumpet or clarion stop is an octave higher.
Aiton's Encyclopedia (1910)
a well known musical wind instrument. It is the type of a large family, including the bugle, horn, trombone, cornet, etc. The essential parts are a tube, cup-shaped for the mouth at one end and bell-shaped at the other. The tones are produced by the vibrations of the player's lips. The simple trumpet is straight; the cavalry trumpet is bent twice upon itself; the orchestral trumpet is fitted with a sliding section for changing the length of the tube. The addition of finger holes and valves increases the range of notes. The trumpet is the traditional instrument of war. Mars is represented in art as blowing the trumpet of war. Its peal is stirring and imperative, putting life into the feet and courage into the heart. The trumpet's call is the signal of advance, the signal of the wild charge. See Orchestra
What Has Changed in the Last Century
When Collier's wrote in 1921 it treated the English slide trumpet as the genuine article and dismissed valved instruments: chromatic trumpets "are sometimes used, but the tone is by no means to be compared with the true trumpet tone." That judgement lost. The slide trumpet and the whole apparatus of interchangeable crooks vanished within a generation, and the three-valve trumpet in B flat, with a C instrument for much orchestral work, became the universal standard; piccolo trumpets in high B flat and A now carry the Baroque parts of Bach and Handel. Aiton's 1910 line that the trumpet is "the traditional instrument of war" also dates the entry: from the 1920s onward, with Louis Armstrong and the players who followed him, the trumpet became above all a jazz and popular solo voice. The organ trumpet stop Collier's describes is still built and still named the same.
Written for this edition, 2026.