[Trombone-l] What do that numbers mean?

[Keith Marr]

>From time to time I come across a horn the bore of which is referred to by a number. For example the Conn Constellation 48H I saw advertised recently was referred to as #3 bore (which apparently means 0.500").

Does anyone know what are all the numbers on this system and whose idea it is/was? i.e. does it only refer to Conns?

Cheers!

Keith in Bb/F/D
Bass Trombone
St Albans Symphony Orchestra
North Herts Big Band