B-615 ENGINEER'S RULE. Robert Hawthorn. In 1832, Mr. Hawthorn, a civil engineer in Newcastle on Tyne, took the standard Routledge engineer's rule, rearranged the scales and crammed it full of all sorts of other useful information (like the capacity of a "chandler" of coal) and produced the Hawthorn Rule, as described in detail by Jane and Mark Rees on page 157 of The Rule Book. Most examples, as shown by the Reeses, were two fold boxwood, but this is a four-fold ivory and German silver version marked "Improved and Arranged by Rt Hawthorn." Nice and straight, only slightly yellowed with all its pins, but, alas, with a 1/4" square chunk broken out by the hinge. But for that, would clearly rank as a fine example of a very uncommon and extremely cool early engineering rule. From the Don Rosebrook collection.Good+ 400-800 NOTE: Absentee bidding ends 5:00pm EST on Friday, March 29, 2019. Live auction is at Camp Hill Radisson, 9:00am, March 30, 2019, Camp Hill, PA.