How To Date Your W. & L. E. Gurley
Survey Instruments:
Gurley instruments can be tricky to date
because not all Gurley instruments are serialized. Gurley started using serial numbers in November 1908
and that serial number actually contained the
year the instrument was manufactured. The serial numbers can be found
on levels, transits, and larger compasses.
Any level, transit, or larger compass manufactured after November
1908 will have a serial number on it located on the level bar, face of the compass, or on
the vernier plate. Gurley may have started to use serial numbers because
of a second location that was opened in Seattle in 1908 creating a need to keep
track of the instruments sold out of both locations.
The serial number log books for Gurley are
currently held at the New York State Museum. The first instrument listed in Gurley’s
serial number log book is number 81. Since Gurley did not start using serial
numbers until November 1908, this was not the first instrument made by Gurley
that year but it was the first serialized instrument made in 1908. The first fifty
instruments serial numbered 81-850 were all destined for the Seattle branch.
The first digits of the serial number indicate the year it was made; i.e.,
serial number 9254 was the 254th instrument made in 1909.
Two examples are shown below. The image on the left is serial number 13601
which would be the 601st instrument made in 1913. The image on the
right is serial number 14725 which would be the 725th instrument made
in 1914.
Gurley also used a
different serial number system believed to have been implemented for Government
contracts. Those substitute letters in the serial number are broken down as
follows::
W = 0
A = 1
N = 2
T = 3
G = 4
U = 5
R = 6
L = 7
E = 8
Y = 9
An example of this
type of serial number is TL1258 which indicates this instrument was the 1258th
instrument made in 1937.
***Special Note About Gurley Levels***
Gurley levels were
serialized starting around 1900. William Bastedo, who ran the Level
Department began the practice of serializing the levels, perhaps on his own.
He had a numbering system that was not the same as the system later adopted by
Gurley in November 1908 and described above.
If your level has a serial number on the bottom side of the tripod plate it
was probably made between 1900 - 1908. Remember the plate could have been
replaced.
Dating Gurley instruments prior to 1909 can be very difficult.
The best source for dating information on Gurley transits made before 1909 is a
book called The Complete Guide to Early W. & L. E. Gurley transits.
This
book
describes the best methods for dating Gurley transits but also has
information in it that can also help date other Gurley instruments such as
engraving, Case tags, and design changes which were also used on compasses and
levels.
In the book you will find Gurley history, employee
information, catalog and manual information, patent information, over 500
illustrations, and descriptions of Gurley transits and options.
Demonstrated are the best known methods for dating transits made between 1845
and 1908, before serial numbering, using design changes, patents, options, and
other indicators. Additionally there is a Glossary of Terms to assist you in
your research.
Transits are broken down by model with images to help guide you through the
dating process. Inside you will find complete sections that cover the
Surveyors’ transit, Engineers’ transit, Vernier transit compass, Light Mountain
transit, Reconnaissance transit, Explorer transit, and the Builders’ transit.
Preview Deluxe Color Edition
Preview Black & White Standard Edition
|
|
