Expert: Kenton Scott - 9/4/2011

Question
QUESTION: Hello, one of my older horns a Holton Revelation/#48 from the mid 1920's has a bore marking/the numeral "1" on the 2nd valve casing.  I am aware of various bore markings such as 0, 00, 001/4 and variations but never a 1.  I do not have a tool (working ) at the moment to measure the 2nd valve slide, but know that it is a good deal larger than my Ambassador coronet's 2nd valve's bore (2nd valve slide). Any info on bore markings of the Holton will be appreciated.
Joe

ANSWER: The Conn Loyalist has this chart on bore sizes for Conn instruments.

http://cderksen.home.xs4all.nl/ConnBoreSizes.html

I don't know that Holton used the same measurement scheme.  But it was probably at least similar.



---------- FOLLOW-UP ----------

QUESTION: Thanks for the quick reply Kenton.  The Conn models certainly do have quite an extensive bore marking system, and they do use numbers and fractions.  Unfortunately, the similarity ceases there. The '1' marking on a Conn horn would represent a .4375" bore. Quite small compared to my Ambassador's/cornet a .468 0r .469 .  As the Holton 48's 2nd slide took in the Ambassador cornets 2nd slide 'crook with room to wobble, the Holton must be larger than .468 or .469. Perhaps you can network with colleagues and get back with me?  Thank you, Joe

Answer
I'll post some inquiries and see if anything comes up.

Here is one response:
Holton does not seemed to have used a number to designate an absolute tubing size the way Conn did, but rather by instrument.  Thus, "00", "0", "1", "1 1/2" etc. are all relative to type horn.