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Re: Why a silver index scale?
From: Brad Morris
Date: 2016 Mar 26, 17:55 -0400
From: Brad Morris
Date: 2016 Mar 26, 17:55 -0400
Hello Geoffrey
I'm not a metallurgist, yet I think the fact that silver is quite soft would permit the engraving of fine lines. The corrosion resistance of brass would be appreciated for salt water exposure, yet would not engrave quite as nicely as the silver.
In my view, an arc of gold would be a better choice (excluding cost) as it is even softer, yet does not tarnish like the silver
Brad
On Mar 26, 2016 4:35 PM, "Geoffrey Kolbe" <NoReply_GeoffreyKolbe@fer3.com> wrote:
Why is that on sextants, it was the usual practice to engrave the index scale on a silver band inset into the brass frame of the sextant?Geoffrey Kolbe
