Description and Notes:
The above picture shows the two sides of this well preserved, rare early example of the A. W. Faber slide rules. This one is dated to the beginning of the twentieth century as no model number can be found on which, and this, according to Slide Rules: A Journey through Three Centuries, indicates that it is among the earliest ones produced by Faber. In addition, the company's name was changed from A. W. Faber to A. W. Faber-Castell in 1905, although the trademark stamped on their slide rules remained unchanged untill about 1913.
The stator and the slide of this rule are made of boxwood and celluloid veneer. The framed cursor is made of aluminum and a glass window with scratched hairline, a steel leaf spring is fastened inside the bevel edge of the frame. Although there is no identification number on this rule, it is likely to be the standard rule in the 300 series (Model 360), as it has scales A/B, C/D on the surface and with the additional S, T, and L scales on the back of the slide. The length of this rule is 26 cm, but the center portion of the stator has the scale from 27 to 51 cm to facilities the measurement of longer lengths.