Collections Item Detail

DescriptionExpedition Alidade, model 5189A, made by Keuffel & Esser Co., New York and Hoboken, (1936.) Metal and glass, 11-1/2" long x 3-1/2" wide x circa 3-1/2" high; dismountable striding level. With: oak wood case, hinged lid and leather shoulder strap. Lacking: sunshade, adjusting pin. Also not present is any printed instructions or manufacturer's sheet. Serial number on blade: 66529. Date of manufacture determined from serial number marked on blade below telescope. The number places it as manufactured in 1936 based on "First Instruments of the Year" serial number chart in January 1991 issue of Surveyor's Historical Society magazine, "Backsights." The smallest version of this style alidade made by K&E. It was significantly lighter and more manageable for carrying to areas of difficult terrain or long distances beyond animal or motorized transportation. It did not have the typical high post for the telescope found on the more common standard alidades and the blade at 11-1/2" was 8-1/2" shorter. It was for a plane table and plane table outfits were available, but this alidade could be purchased separately. See page 442 of the 38th edition catalog of 1936 for a depiction and description of this instrument and 444 for the outfits. Also see pages 440, 441 and 443 for related accessories and illustrations. Striding (or stride) level stores on post at front end of the blade. Must be removed before storing alidade in case. Case described in catalogue was leather covered (shown on page 441 of 38th edition) which the one here is not. It does not have any K&E markings. It is apparently not original, but it was made for this instrument and was likely a later replacement made by K&E. Leather strap color does match leather color used in other K&E leather products such as compass covers, slide rule cases, etc. Case has two discolored marks on the exterior where previous plates or labels were once present. K & E office and factories were in Hoboken when this item was made.