Strange (Remaining) Station Mark: Whatszzit?

[+pgrig]

Hi All--

 

On Benchmarking Opening Day, 2009, I visited MY2792.

 

Please take a look at my MY2792-Detail photo, or the detail photos by Munin (6/28/05) or ddnutzy (5/1/05). I'm wondering what this is.

 

At first I thought it was an ordinary "only the stem remains" station. But what remains at the "stem" location doesn't look much like bronze disk metal. Rather, it looks like some sort of weathered-down, pitted compound, which had small, entrapped bubbles. And it seems to have been center-drilled. The photo by ddnutzy even appears to show a small pin located at the center of the "stem" (similar to that in the early 1930's reference marks set around here by the Mass. Geodetic Survey (MAGS), which monumented this station in 1934).

 

The Datasheet shows a Recovered-Good entry by MAGS in 1978. Today you can clearly see what looks like old disk cement around the "stem", and a faint outline of a former disk in the rock itself (shows nicely in Munin's photo). No resets are mentioned.

 

What's going on here? Do bronze stems ever weather-down to this? Did some disks have a center hole running down their stems? Is this an unlisted reset of some sort, with only a center pin (or compound) re-set and the actual disk not replaced? Something else?

[+t8r]

Nice job with the photos Paul. Looks like we are looking at the potting compound that held a standard disc into the rock. A standard disc would have been a bronze mushroom of which there bazillions pictured in the logs and in the forums. Some enterprising soul prized out the stem that remained and was described.. At an earlier time another soul had broken off the disc and taken it. One nice thing is that there are so many of thesa around that they have very little value. Some jerk has a bronze stem in a box in the garage. Woo hoo. Wonder how big a statue I could cast with the bronze from a thousand of these.

[+pgrig]

Thanks, t8r. But I don't see how prying out the stem (which I don't think happened here) would leave material that looks like my Detail photo where the stem used to be.

[+t8r]

The more I look at your picture, the more it looks like a piece of bubbly basalt that has been mortared into the setting of an earlier station. If the hole were 1/2 to 3/4 inch diameter and 2 or 3 inches deep? That would the correct size to pound a self anchoring disc/stem into.

 

Or possibly:

 

Plumbago Packing (lead)

 

I remember seeing men use it for sealing cast iron sewer connections by pounding it in with a hammer and a rod that was made for that purpose.

 

We cant tell what size of black stuff or the hole. ??

 

The following is from

[url=http://www.archive.org/stream/durhamrubbercomp00durhuoft

 

Our Plumbago Packing will pack any kind of

air, steam or water joints. It is particularly well

adapted for packing expansion or heated joints, as

it does not burn or char as other packings do.

 

It readily conforms to any unevenness in the

surfaces between which it is placed, and therefore

obviates the necessity of facing joints, thus reduc-

ing the cost of construction and repairs.

 

By the application of either a little naphtha,

rubber cement, or both, to the surfaces two pieces of

Plumbago Packing can be put together, and, under

pressure, will become as solid as one piece. In this

way uneven joints can be made quickly, easily and

economically. When this packing comes in contact

with heat it becomes vulcanized and of a metallic

nature, so that oil does not have the injurious effect

upon it that it does upon ordinary rubber packings.

 

Plumbago Packing, with wire or duck insertion,

made to order.

 

Scraps of Plumbago Packing of our manufac-

ture, without wire or duck insertion, may be return-

ed to us, and a fair price will be allowed for them.

 

I believe plumbago was also used for cementing bolts and things into concrete or stone.

Edited April 13, 2009 by t8r

[mloser]

It looks like some survey party may have set a nail into the stem hole with some sort of compound to use as a center point.

[+seventhings]

I've seen a few similar things, but they have looked more like conventionally melted lead. I agree with mloser - probably a field salvage job by a subsequent survey party, but I have no clue as to what the compund may be.

 

Will

[+pgrig]

Thanks, all.

 

OK mloser and seventhings. Your "temporary re-set by field party" was my last guess above, and I suspect the correct call. I've just never seen this in my lengthy (1-year) career! :-) By the way, the drillhole for this mark would appear to be the standard size and (I suspect) depth. It's just one of dozens of 1934 MAGS disk installations around here.

 

-Paul

[+Klemmer]

I'm in agreement with the last 3 posts. Seen some similar stuff done out here, and worse (PVC pipes!)

 

If anyone is really interested in determining exactly what the material is, Chemir Analytical Labs did a great job for my company recently in exactly identifying some contaminating material of unknown origin inside one of our products. Good company, good work, quite pricey ($3,000+).

(no financial relationship to Klemmer)