What is it? Set 238

[R.H.]

It's been a busy week for me so I haven't had time to check out the options for another news reader, so I'm going to have to use Google groups until then.

[kfvorwerk]

1339. jig for drawing dovetails for furniture making. 1342. I'm going to say it's for expanding muffler pipes. Karl

[Woodie]

1339 - Dovetail marker

1342 - Pipe expander (for automotive exhaust pipe?)

1343 - Overly complicated bottle opener?

[Nahmie]

1342 is definitely a tailpipe or muffler pipe expander for auto exhaust systems(DAMHIKT)

[DanG]

1339. Looks to be some type of dovetail marking gauge. 1342. Tailpipe expander.

[Northe]

Rob,

1338: I think it's an electrometer. Applying static electricity or high DC voltage to the side terminals should cause the hanging object to be attracted to one side or the other.

Northe

[Roger Haar]

Hi,

Item 238 looks a bit like an electroscope, but from the photo, there is a lot that can not be seen. The foremost question is," is there a gold leaf attached to the central hanging thing (or should there be)? What is electrical isolated from what and how well? Do the side things slide and are the hollow, with lenses? If the answers are yes to these questions, this could be an electroscope used to measure ionizing radiation. I have seen electroscopes mostly like this but with only one side assembly.

Thanks Roger Haar

R.H. wrote:

[Matthew T. Russotto]

1339: a tool for drawing a particular truncated triangle? 1340: 90-degree rolling pin

1341: Worlds poorest fondue set

1342: Used for spreading pipe

1343: Elevator shaft key. (yeah, I always guess that)

[Smaug Ichorfang]

The more I look at 1338, I wonder if it is indeed aa metal-foil electroscope. Typically these have very thin pieces of metal foil suspended from a central conductor. The center piece in this looks way too thick to be an electroscope. Does the center piece move; can it pivot from side to side? Are the two terminals on the sides adjustable? Is it possible this is a tilt switch of some sort?

[Brian Lawson]

SNIP

Naw. Prior to the 40's, flyball governors were used to do that.

[Brian Lawson]

All I know is what I see. 25 cycle power, using a BIIIIIIIGG brake to govern the speed of the generator. Brake is operated by fly-ball governor. Whether or not synchronous clocks were "invented" in 1916, they sure were not in regular use is common practice. Heck, I still do have a pendulum clock that keeps good time.

Brian Lawson, Bothwell, Ontario.

[Curt Welch]

The way to regulate it accurately is to drive a clock with the current and compare the time of the clock to an accurate time source (like the sun).

For the clock problem, the short term frequency is not as important as the long term average frequency. So when the clock is running behind, you just speed up the system a bit until it catches up. The fact that the frequency is only accurate to 5% is not important if you can keep the long term average accurate which is easy enough to do just by driving a synchronous clock from the power.

I was once told that the above is what power companies actually did (at some point in history). Don't have a clue if it's true however.

[Rob H.]

I sent some similar questions to the guy who emailed the photo to me, but never got a reply. I think that the device belongs to a friend of his and it's not available for him to take a closer look.

Rob