1918 E.A. Couturier Continuous Conical Bore (Bb/A) Pro Trumpet in Original Case!

This listing is for a near-mint condition 1918 E.A. Couturier Continuous Conical Bore trumpet in polished raw brass with both the Bb and A tuning slides in its original case!  It is very rare to find one of these century-old trumpets and its original case that are both in such excellent condition!  Please zoom in on all of the photos to see the condition of both the trumpet and the case (the case is shown in the last two photos).  The valves have excellent compression and function perfectly!  With the continuous conical bore, the receiver is small, which is designed to fit a standard cornet mouthpiece (not included).

I tested this trumpet using various cornet mouthpieces.  A typical cup gives a beautiful tone that sounds in-between a trumpet and a cornet (but with better intonation).  A deep mouthpiece gives a darker tone that sounds in-between a cornet and a flugelhorn.  It sounds really beautiful with any standard cornet mouthpiece.

Key Details & Historical Context

The Maker: E.A. Couturier (1869–1950) was a virtuoso cornetist and inventor. He established the E.A. Couturier Band Instrument Company in La Porte, Indiana.  

The Concept: Couturier argued that conventional brass instruments suffered acoustically because the tuning slides and valve passages utilized cylindrical tubing, disrupting air expansion. His design patented a "Continuous Conical Bore" where the instrument gradually expanded from the mouthpiece receiver all the way to the bell flare—even through the valve section.  

Manufacturing Era: Couturier obtained his core patents in 1913 (U.S. Patent 1,073,593) and produced these instruments primarily between 1916 and 1923.  

Mechanical Innovations

To preserve the continuous expansion throughout the instrument, Couturier had to re-engineer standard brass mechanics:  

1. Expanding Valve Passages: Each valve port and inner circuit was progressively larger on the downstream side than the upstream side.  

2. Stepped / Tapered Tuning Slides: Instead of equal-diameter inner and outer slide tubes, the distal legs (closer to the bell) were wider than the proximal legs (closer to the mouthpiece).  

3. Distinctive Aesthetics: Many Couturier cornets and trumpets featured unique "bowtie" wrapped tubing configurations to manage the geometry required for the expanding bore.  

An E.A. Couturier Continuous Conical Bore trumpet or cornet with serial number 2139 was manufactured in 1918.

Dating & Serial Number Context

Serial Number Range: Production of the E.A. Couturier Co. instruments in La Porte, Indiana, began around serial number 1000 in early 1918. By the end of 1918, production had progressed past serial number 2500–3000.

Factory Location: Instruments from this early serial block (1000–3000 range) were manufactured during the initial production run at the La Porte, Indiana factory following E.A. Couturier's 1913 patent.