Kern Dating
This link will take you to a different website that will help you date your Kern Instruments.  This site is in German but can be translated easily with Microsoft's Bing Translator.

Wild Heerbrugg Dating
This link will take you to a different website that will help you date your Wild Heerbrugg Instruments.
 

The Complete Guide To Early W. & L. E. Gurley Transits

This publication is the most information-packed guide to Pre-1909 W. & L. E. Gurley transits ever produced.  You will find 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              

                                                                                  
 

I am a Land Surveyor that has been collecting antique surveying instruments for 23 years.  There are few reference materials available on antique surveying instruments so this new book written by Brian Aregood entitled “The Complete Guide to Early W.&L.E. Gurley Transits” has been a real eye opener for me.  The book documents in great detail all the minor changes in the evolution of Gurley transits and the year in which the change occurred.  Dating pre-1909 Gurley transits has always been difficult, this is the time before Gurley started putting serial numbers on their instruments. 

This book is really the quid essential reference for dating these pre-1909 Gurley transits, it is amazing just how much I did not know about them.  It also provides some insights into early techniques, such as the early methods of graduating the vernier scales, that are applicable to the construction of all early transits and compasses. The book does a fantastic job of documenting the changes to the construction of all pre-1909 Gurley transits including the earliest Gurley transits made by Phelps and Gurley, and contains great detail regarding the evolution of the Gurley solar transits.  It even contains a list of the workers at the Gurley factory who sometimes signed and dated an instrument after it was constructed under the plate.

This book is very well written and organized, but what really sets it apart and in my opinion and is the most useful aspect of the book are the prolific number of photos actually showing by example the changes being discussed.   I ordered the color version of the book and would recommend the color version to others over the black and white; this book is well worth the price.  I highly recommend this book to collectors of any antique surveying instruments, especially to those who collect Gurley instruments.

More to Come!