Y-354. PATENTED T-SQUARE. 20-1/2" boxwood head with brass edge. The handle is 18" long with a sliding extension that adds another 10". There's a brass plaque marked Patent 18772 1908 - looks like an English patent that we haven't been able to locate. Presumably the sliding extension is the subject of the patent but the weird thing is that the handle is tapered which doesn't make sense for a square. A mystery, but well made. Good+ 80-150 **All absentee bids must be placed by end of day, Friday, January 24, 2020. Current high bids can be obtained by calling our office at (800) 248-8114. See Auction Rules page for more information**