The back of the rule contains four pairs of log-log scales (LL0 to LL3 and LL00 to LL03), C, CI, D, and L scales, and Castell’s unique W scales, which are like double-length C and D scales.
They can be used to compute square roots, or for multiplication and division with the precision of a 20-inch rule.
This inexpensive one-sided white plastic (Geroplast) five-inch linear slide rule has a transparent plastic indicator.
Like on most Castell rules, the scales are self-documenting, meaning that the scale name appears at the left end of the scale, and its mathematical formula is at the right end.
The cursor has gauge marks for HP/k W conversion, area of a circle, and working with factors of 3.6 (e.g. The instruction manual, in English, was in excellent condition, with just some yellowing of the paper with age (no musty smells).
Yet in the conservative German Empire of fin-de-siècle Europe, the marriage of a Faber into a family of the high nobility was regarded as too bold a leap upward socially.
A morganatic marriage would have been required, and the Faber pencil works could not have remained in the hands of their descendants because trafficking in commerce was still considered an act of social derogation among members of the Hochadel.
The Faber-Castell 2/83N desktop rule (and its less common pocket-sized sibling, the 62/83N) is probably the most sought after slide rule, especially after Dr.
Clifford Stoll’s Scientific American article, When Slide Rules Ruled, drew attention to this epitome of slide rule development. Stoll writes, the 2/83N “is considered by some to be the finest and most beautiful slide rule ever made.” I purchased this 2/83N directly from Faber-Castell as new old-stock.
Today, the company operates 14 factories and 20 sales units, with six in Europe, four in Asia, three in North America, five in South America, and one each in Australia and New Zealand.
the sons of his only son Wilhelm (1851–1893) (by his wife Bertha Faber , daughter of Lothar's younger brother, Eberhard , who had founded the New York branch of the company) having died young, a marriage for his granddaughter and heiress Ottilie was arranged with a scion of one of Germany's formerly ruling comital dynasties.
When the Holy Roman Empire was dissolved under pressure from Napoleon I in 1806, the Castell lands were annexed by the Kingdom of Bavaria.