878: Guess... Seems to be a device for measuring/setting pitch/grade/angle.
Unless it is a trick of perspective, the right side seems to not be
perpendicular to the bottom. Why would one want to measure the angle of a
near vertical thing? My guess is a mortar aiming gauge.
879: At first sight it looks similar to stroboscopic discs used to
set/check turntable speed. But... With 6, 91 (7x13) and 182 radial
markings, it doesn't make sense for common turntable rates. I still guess
it is used as a strobe disc, but I've no idea for what.
880: Unknown has already identified a set of cork borers.
882: Traffic light? Go/stop indicator for
883: Why would anyone want to check magnetic north alignment precisely but
only over a small range? Perhaps used to carefully calibrate deviation of
magnetic north from true north. For making maps of magnetic deviation?
878. Clinometer, for measuring angles relative to the vertical. This is
a military one and not uncommon, used for setting elevation of light
artillery, mortars or heavy machine guns.
881. Can't tell from the pictures, but it looks like a sodium press.
You stick a lump of sodium in and squidge it into spaghetti. Used as a
reagent in some chem lab processes.
883. Obviously electromagnetic, but I think it's more electro- than
geo- Probably a demonstration galvanometer, like a telegrapher's
galvo only bigger. Wrap a few turns of wire around and you'll get a
deflection depending on charge and current direction.
Take a look the PPH 405.
The discs have etched sections, interupted by plenum rings. The paint
follows the smooth path between the edged segments rather than the
rougher/etched section. The etched sections also set up a Magnus
effect, directing paint somewhat by increasing friction. The majority
of the paint-spray is directed by high voltage electrostatic
Different size discs are used to vary the relative speed at
circumference as viscosity differences in paints dictate and 'leap-off"
Anyone for a game of Balderdash?
I guess 879 could be a paint disc, but the disc on the link doesn't look
much like the one on my site, and it's hard to tell what size it is from
looking at the photo. I'll need stronger evidence before I agree that the
air disc is for painting.
Thanks for the link, I was looking for one but didn't find much.
Someone told me that he was seeing two different tools for number 881, it
looked fine to me both at home and at work, but if you saw a photo with a
blue wall in the background, that was the wrong picture. I've just reloaded
both images for that number, so you should see the Stellon device assembled
in the first photo and dismantled in the second.
Low probability guess. There once was a company by the name of R.S.
Knapp (NAPCO) that sold drafting supplies. Using the grooves etched into
the disc (if they are deep enough) one could guide a pencil in order
to use the disc as a template to draw the blades of a tangential turbine.
The compass is similar to the compass in my theodolite. It is used to
align the instrument to magnetic north.
O.K. Posting from rec.crafts.metalworking again, as usual.
878) A device for measuring (or setting) to some degree of precision
the deviation of a surface from level.
The scale is not degrees -- so I might think that it is intended
to dial in a specific elevation angle for an artillery piece,
with tables converting that to range with a given charge.
The gear teeth are at the same intervals as the marking, so I
think that you pinch the two tabs to slide it to close to your
desired setting, and then rotate the knob to dial in a fraction
of one of those units.
The level vial is almost certainly a lot more sensitive than
anything except a Starrett "Master Precision Level" or one by
879) I've never seen one of these before, but I suspect that it is
a form of air cushion bearing.
A Google search finds that NAPCO makes (or sells) automotive
parts and motorcycle parts -- but this does not look like one of
either to me.
880) I thought that you had put a similar one up in the past year or
two. It is a chem lab "cork borer". You select the tube for
the size of glass tubing which you wish to fit, and bore a hole
through the cork. It is also missing a central rod with a
knurled knob on the end which is used for pushing the cork out
of the smallest tube. The other sizes are cleared by using the
next size down.
Note that the free end of each is beveled. (Hmm ... *maybe*
what you showed before is the tapered brass core with a hinged
knife blade for sharpening these cork borers.)
881) For making *something* under pressure. Perhaps Vegemite, given
the Australian provenance?
I would have liked closer shots for the individual parts,
instead of that long shot with them all spread out along a
882) A signal lantern -- perhaps for something like railroads.
You rotate it to present either the horizontal bar or the
vertical bar -- indicating "no-go" or "pass", I expect.
883) With that long a needle, it would be quite sensitive.
I think that it could be used in conjunction with a map and a
table to refine "sights". Put the map on the table, align the
object to the North-South line on the map, and rotate the map
and the compass until it reads zero, and then look around for
recognizable objects (and take sights to them) to determine
where you are on the map.
Now to see what others have guessed.
Email: < firstname.lastname@example.org> | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
On 19 Jan 2007 05:32:53 GMT, email@example.com (DoN. Nichols)
you may be almost right.
substitute 'plane table' for table and you may have it.
plane tabling dates from before the 1950's. the mapping surveyor went
to a spot and put up his plane table and levelled it. then put the
piece of paper on it positioned so that the point on the emerging
drawing was plumbed over the spot on the ground. the sheet was
oriented precisely to the detail and radial lines drawn to prominent
objects. by moving around to other points and plotting to prominent
objects the entire detail could be developed on the map.
you would only need a needle with a small movement to aid in
orientation of the map.
I've never actually seen one so I'm guessing and the technique
predates my surveying time.
a land surveyor's plain tabling compass is my guess.
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