||There is no date stamp on the back.
According to the book from Peter Holland, this type
was only manufactured between 1906 and 1912. Most likely this specimen
is from the end of this period, as it doesn't have railroad track scales.
On the box is written (vaguely); P.E. Schneider,
1st093, 2/7-13. This suggests that the slide rule was bought in 1913!