There was nothing that struck fear in the hearts of many high school students like the slide rule. I could never really understand, because I loved mathematics and my slide rule. But so many seemed terrified. Perhaps it was all those numbers.
Admittedly, the whole device is rather arcane looking - scales with tiny divisions and numbers completely cover both sides. The slide rule is an analog device, and numbers can be read to only three significant digits without any reference to magnitude. In other words, 123 is the same as 12.3, 1.23, .123 etc. So interpretation of answers requires keeping note of and calculating (often just using memory) the magnitude of the answer, which is only a series of digits - i.e., you need to know where to put the decimal point.
The slide rule was used for multiplication, division, and for functions such as roots, logarithms and trigonometry, but not for addition or subtraction. These are precision instruments and require careful use - unlike a digital calculator, answers can vary depending on the skill of the user. Keuffel and Esser introduced them to the United States, and I am proud to own one.
The Keuffel & Esser Co. was founded in 1867 at 79 Nassau Street by two German émigrés, Wilhelm Johann Diedrich Keuffel and Herman Esser, as importers and jobbers of European drawing and drafting materials.
Early on, the firm was successful and continually expanded, moving locations several times. 4 K&E tentatively started manufacture and published its first instruments catalogue in 1870; opened its first retail store with a showroom in Manhattan in 1872; transferred its manufacturing to Hoboken, N.J., in 1875; moved its headquarters to 127 Fulton Street in 1878; and constructed a new factory building in Hoboken in 1880-81 (which was expanded in 1884, 1892, and 1900). The firm was incorporated in 1889, with Keuffel serving as president until his death. K&E, which had introduced imported slide rules in 1880, began their first American manufacture in 1891. The company became strongly associated with the product as the nation’s foremost manufacturer, credited with popularizing slide rules in the United States. In 1892-93, K&E constructed a new building at 127 Fulton Street to serve as its retail salesrooms and general offices.
K&E played a nationally significant role in the technological development of the United States. K&E products, which included measuring tapes and compasses, were used in countless construction and engineering projects, such as the Brooklyn Bridge, of the post-Civil War boom years, and K&E surveying equipment is considered to have been critical to the westward expansion and development of the country.
K&E’s offices and salesrooms had been located at 127 Fulton Street since 1878. This address was close in proximity to the financial district and the offices of many architects and engineering firms. Over the next 13 years,“business increased, doubling and redoubling in volume, year after year,” leading the firm to require larger quarters. In May 1891, the architectural firm of De Lemos & Cordes filed for a new 8-story (plus basement) Keuffel & Esser Co. Building, to house the company’s primary retail salesrooms and general offices. The nearly 25-foot-wide, fireproof steel-and-cast-iron-framed structure was completed in February 1893.
By 1930, the K&E catalogue carried over 5,000 items. You can read more about the building, its history and the company here.
The 8-story building's upper stories are clad in buff brick and terra cotta. The base has an historic 2 story cast-iron storefront, framed by colonettes with spandrels bearing small shields, the company's initials and representations of its products. K&E vacated the premises in 1961. The property will be converted to residential condos.
A slide rule was the engineer's tool and companion, often carried in a leather case which could also be used as a belt holster. You can see my original Keuffel and Esser slide rule and molded leather case in the photo. After reading the history of K&E, I am duly impressed, and I have a newly acquired reverence for that slide rule I have, made by Keuffel and Esser :)