Sohmer

[Newton Hunt]

One way to measure crown from the top side is to use a long stick, two
looong screws and a dial indicator with a long plunger.

Make it it to look like this 		|___|___|.  You calibrate by adjust one
of the screws so you get a zero  	Ö	reading on the dial using a really
flat surface.  If you use additional screws you can check at many
location well into the treble.

The other easy way is to use a thread on the board between the longest
ribs.  Simple but a way even I can understand.

		Newton