_Modern__Blacksmithing_, 1904, chapter 4:
"When a wheel has bolts every smith knows that it will make trouble for
him if he don't get the tire back where it was."
"When bolting a wheel the tire will be out of place unless the tire has
been shrunk alike on both sides of the fellow plates. A smith used to
setting tires will be able to get the holes almost to a perfect fit."
I heard back from the owner of this device, the tubes are connected at the
as seen in a new photo that is posted with the answers, and there is a hole in
stem that goes to the tube. Thanks to everyone who helped figure out this
The rest of the answers for this week can be seen here:
O.K. If the tubes are joined by the block at the bottom,
instead of being a single tube, this probably means that it is not
filled with mercury.
And for 3" difference with mercury, that gives only 1.47 PSI
maximum, and even model steam engine boilers work to near 100 PSI.
With water instead, it drops to 0.108 PSI. Totally useless for
measuring steam head in the boiler, but for checking flow of heating air
through the flues -- that would be a reasonable sensitivity. The units
program does not cover inches of methanol or inches of ethanol, other
likely liquids (though less likely than water, and the brass would show
discoloration from mercury, as it would get shiny for a short time, and
then dull and gray as an amalgam formed.
3021) I should have guessed the broken key extractors, though I have
never seen any.
Another application could be to check for small domestic gas leaks. You
connect it up, then turn off the gas supply and see if the pressure
drops over time. I've not done the calculations but they seem more in
the right range.