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US HELIOTROPE BOX TYPE E1


MEMELPE
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yes but it is used for wich object/units ( artillery, airplane ....? ) and it calculate what ?....distances ....between what and what ?

is this heliotrope a good WW2 ?

thanks

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  • 2 months later...
today i find that item : us heliotrope box type E1 it is marked : " US HELIOTROPE BOX TYPE E1 AMERICAN INSTRUMENT CO "

 

What is it for ?

This heliotrope was designed for land surveying as a target marker when the survey point is far from the observer - typically 10-30 miles or so. At closer ranges an opaque target would be used, and at longer range, a heliotrope with larger mirrors (the record is 194 miles).

 

Heliotropes were invented in 1821 by the famous German mathematician, Carl Friedrich Gauss, and were used by Colonel Everest for the great survey of India. With the advent of GPS surveying, these became markedly less popular, and the US Mil Spec for these (MIL-H-20194E) was retired on Dec. 8, 1995.

 

The heliotrope is set over the point to be surveyed (e.g., located with that plumb bob), and light is reflected by the main mirror (the one bolted to the case) towards the observer many miles away.

If the sun is behind the main mirror, then the secondary (loose) mirror is placed in front of the main mirror, and off to the side, to reflect the sun back to the main mirror. The heliotrope is

sighted in on the observer using the small sights at the top of the aiming posts, then the mirror is adjusted so that the light passing through the aperture midway down the one aiming post

s centered on the aperture in the center of the further aiming post.

 

The usage of the heliotrope is described in section 4.31 (pages 4-40 and 4-41) and Figure 4.26 of

TM 5-232 Elements of Surveying, June 1971, here:

http://books.google.com/books?id=564XAAAAY...amp;pg=SA4-PA40

 

A similar discussion of the box heliotrope, with a diagram rather than a photo,

is in the section titled "Heliotropes" on pp. 4-6 and 4.7 of

Chapter 4: Targets and Signals, in

FM 5-232 Topographical Surveying, here:

http://library.enlisted.info/field-manuals..._232/2324CH.PDF

http://www.enlisted.info/field-manuals/fm-...surveying.shtml

 

The US Geological survey page has a very nice set of photos of the box type American Instrument Company heliotropes here (click on "original" for full size):

http://gallery.usgs.gov/photos/07_20_2009_...3F_07_20_2009_7

http://gallery.usgs.gov/photos/07_20_2009_...3F_07_20_2009_6

http://gallery.usgs.gov/photos/07_20_2009_...3F_07_20_2009_5

 

The US military spec for the box heliotrope is here:

SPEC MIL-H-20194E HELIOTROPE, SURVEYING, BOX-TYPE, WITH CASE

http://assistdocs.com/search/document_deta...nt_number=14150

 

For more on heliotropes in general, see the Wikipedia article and its references:

http://en.wikipedia.org/wiki/Heliotrope_%28instrument%29

 

> is the box complete or not ?

 

It looks like it could be - comparing it to the USGS one and mine,

all the regular pieces seem to be there:

two pivoting mirrors, two aiming loops, gimlet, screw, strap,

and you even have a plumb bob (bonus).

> and is it a WW2 item?

 

I can't be definite on its age, though in balance I expect is is fairly old.

 

These were made over a fairly long period - the spec was not taken out of service until 1995. Every one I've seen has been a little different.

 

However, the physical layout of your heliotrope has much more in common with this one from 1914:

http://celebrating200years.noaa.gov/magazi...ope1914_450.jpg

( this is the tenth figure from the slide show at the bottom of this article:

http://celebrating200years.noaa.gov/magazi...ls/welcome.html )

than from the more modern illustrations:

( Hinged box rather than separate lid, mirrors attached to wood rather than to a metal rail,

secondary mirror is loose, rather than attached to rail, etc.), so I'm thinking your heliotrope is fairly old.

 

If there's a mil-spec number on it somewhere, that would help date it:

MIL-H-20194C issued 16 March 1977

MIL-H-20194D issued 2 Dec. 1982

MIL-H-20194E issued 23 Jan. 1989

MIL-H-20194 retired Dec 1995..

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Even more photos of box heliotropes:

 

The top one is a MilSpec MIL-H-20194 "HELIOTROPE, SURVEYING, BOX-TYPE, WITH CASE".

The serial plate says it was made by "gordon enterprises", and has the following numbers on it:

FSN-6675-240-1892

PO-23-195-R6-11164[T]

MIL-H-20194

P/N D57541

S/N GED-189

 

The bottom one has no legible markings.

 

6784115736_dfd18e1717_b.jpg

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heliographer, thanks for the postings! :thumbsup:

That is about as thorough a discussion as anyone could want on the usage and function of this device. I had the pleasure of seeing a demonstration on its setup and use by an old-timer when I worked for the Forest Service. Neat device in its simplicity.

Terry

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HELLO

on the last picture, the last heliotrope ( the one on the bottom of the picture ) is exactly like mine !

thanks

i ll look for markings ( but i think there is no marks )

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  • 1 year later...

HELLO

on the last picture, the last heliotrope ( the one on the bottom of the picture ) is exactly like mine !

thanks

i ll look for markings ( but i think there is no marks )

 

Here's a seven-photo set of an instrument like yours that was just posted by signalmirror at Flickr.com:

 

http://www.flickr.com/photos/signalmirror/12732327243/in/set-72157629091114108/

 

The photos are marked as usable by others if the author (signalmirror at Flickr.com) is credited.

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