Notes: "The 4092 was K&E’s first log-log slide rule, appearing in the 1909 catalog, although it is believed that it was being sold in 1908. The three log-log scales use e as their base and cover the range 1.01 to 20,000. This one has the “all glass” cursor, which dates it to 1915-1921. Remarkably, the glass has survived with all corners intact. These cursors usually have at least one corner broken off. "
