Fraud Alerts

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Adopted Statement Reproduction Alert

Tips on Reproductions

The Gemmary F-Files

The following statement was adopted by the Surveyors Historical Society on March 15, 1999 and later endorsed by the Board of Directors of the National Society of Professional Surveyors and the American Congress on Surveying and Mapping:

"WHEREAS it has come to the attention of the Surveyors Historical Society that there are several efforts around the world to manufacture reproductions of historical surveying equipment, artifacts, and memorabilia; and

WHEREAS many of these reproductions are difficult to differentiate from original pieces; and

WHEREAS many of these pieces are deliberately "aged" to make them appear to be older than new manufacture; and

WHEREAS many unsuspecting buyers many easily be deceived when making purchases of said reproductions;



1.)  That the Surveyors Historical Society takes the position that all reproductions of historical surveying equipment, artifacts, and memorabilia should clearly state the manufacturer's name and/or date of manufacture; and


2.)  That all people of good character will make no effort to deceive in any manner prospective purchasers as to what they are purchasing."



REPRODUCTION ALERT:  The following are pictures of some of the reproductions that are being sold in the marketplace today.  For the most part, the items are being responsibly represented by the manufacturing seller as being a reproduction piece.  However, in some cases of resale by buyers, the items are not being clearly identified as being reproductions and thus giving the impression of being an authentic antiquity.  Take a look at the following or visit for a fairly complete listing of reproduction pieces available.


reproastrolabe.jpg (45115 bytes)

reproengcomp.jpg (44592 bytes)

reprocompass.jpg (48355 bytes)

reprodumpy.jpg (43388 bytes)

reprostancomp.jpg (39038 bytes)


Engineer's Compass


Dumpy Level

Stanley Compass

reprosundial.jpg (45269 bytes)

reprosurvcomp.jpg (44022 bytes)

reprotheo.jpg (66107 bytes)

reprocircum.jpg (22895 bytes)

alidade1214.jpg (8226 bytes)


Surveyor's Compass




ncompasssurvey4inprismbox.jpg (45101 bytes)

repro-transit-e.jpg (19294 bytes)

repro-theo.jpg (134482 bytes)




For information on reproduction Brunton compasses visit:  "Brunton Pocket Transits"




With the increase of surveying instrument reproductions in the marketplace, buyers of antiques need to be alert to subtle and confusing markings as well as mechanical components that can help identify a reproduction piece from an authentic antique.  These new instruments have been widely reported throughout the United States as well as most of the tourist markets in Europe.  Some of the reproductions are offered in wooden cases with brass hardware which also has been made to appear old and have markings which may be mistaken for authentic.  The following are a few tips that may help in your detective work:


Everyone likes a bargain.  However, keep in mind that in the case of antiques a low price could be an indicator of questionable authenticity or condition.  For surveying equipment, an average authentic antique piece could range in price from $500 to several thousand dollars.  New reproductions of this type typically range from $50 to several hundred dollars.


Many reproduction pieces today carry what would appear to be legitimate colonial era markings.  Although modern reproduction pieces are frequently made in India, you will find many (but not all) reproduction pieces are being marked with names of European or English cities, such as "London."  Also, many new pieces are being marked with what would appear to be the maker's name, such as "Stanley," and in addition, may carry a four-digit number such as "1902" which would give the impression of a year of production.  A reproduction manufacturer meets all legal customs requirements by affixing a removable paper label identifying the country of origin, such as "Made in India."  Craftsman's marks of yesteryear are easily copied and forged.  A better test of authenticity would be to examine how the piece is made.


One of the first questions to ask yourself upon inspection of a piece would be, "Can this instrument reasonably perform the function it was designed for?"  Authentic antique instruments were generally designed for a specific task.  If a piece cannot perform the specific function for which it was designed, then it should be considered suspect.  A person does not need to be schooled in the use of an instrument to be a good detective of authenticity.  Simply use logic.

Any part of an instrument that is supposed to move should move.  Levers, arms and dials should freely move.  Knobs should tighten and loosed easily and not be frozen in place.  For pieces with an optical system, like a telescope, you should be able to bring the lens into focus.  On instruments which measure angles, check the degree markings to make sure that they are located correctly.  For example, make sure that the 90 degrees mark is at a right angle from 0 degrees and 180 degrees is directly opposite the 0 degrees mark.

Try to be thorough in your inspection of the mechanical components of an instrument.  On a detailed inspection of many of the new reproductions one can find the use of modern materials such as plastic.  Small plastic washers have been used, and buried deep inside a pocket sextant could be a lens housing made of plastic.  Often these parts are smaller than 1/4" and quite frankly could be easily overlooked, especially when they are part of an intricate mechanism.  Best advice--be as thorough as possible.


Don't overlook inspecting the instrument's surface finish.  A finish that shows grinding marks or has a rough surface would most likely be a sign of a reproduction.  Instrument makers of yesteryear crafted beautifully made, precision machines.  An authentic antique instrument may have a few dents and scratches from normal use and wear, but these should be random in size and placement.  Modern power tools generally leave grinding marks that are regular in size and often in an obvious repetitive pattern.


Another area for inspection is the quality of the calibrated markings, such as degrees, inches, angles, etc.  The markings found on most antiques were carefully scribed or engraved with sharp, fine lines and remain clear and easy to read even after years of normal use.  However, on many of the reproductions the markings may appear either faint, shallow, irregular, oversized, hard to read or crude.  Some of the reproduction markings are stamped by machine rather than engraved, a process which tends to squash the outline of the numbers making them appear crude.






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