Versalogs sold in this case were listed as 1460L. A logarithm relates one number to another number much like a mathematical function. It is virtually identical to the in my collection except for the bamboo, in this case. Year Codes A B C D E F G H I J K L M 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 N O P Q R S T U V W X Y Z 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 Month Codes A B C D E F G H I J K L Jan. Painted or imprinted slide rules were viewed as inferior because the markings could wear off.
Knowing the existence of these variants can help in identifying a particular rule. Slide rules come in many different styles, including sliding bars and rotating cylinders and circles. The Pickett rules offered here for sale are arranged more or less in order of increasing complexity. Post sold Hemmi slide rules exclusively from 1932 to 1941. Here are scans of some Hemmi cursors with information about their ages. This is done to enable comparison between different rules.
Bamboo is dropped from the labeling, leaving only Hemmi Japan. There are 16 different rules bearing the number 1444, including suffixes, from 1910 to 1971. Moreover, Hughes Owens also adopted the brand name Geotec for its slide rule and drafting products somewhere between June 1968 and May 1969. Materials being used Slide rules entrely made of plastic only appeared in 1951. Virtually identical in construction to the Versalogs, although this one has a simpler black leather case which seems inferior compared to the richly coloured Versalog case shown above. With the log function of a scientific calculator generate the numbers, mark them out with a metric rule and hey presto. Show your date respect by arriving on time.
On a given rule you will find that scale sets, model numbers, construction methods, printing styles, packaging, and logos evolved. Hemmi stopped making slide rules about 1975. The 1446-D was made by Lawrence Engineering Service. Hemmi was granted Japanese patent 22129 in 1912 for laminated bamboo construction and success seems to have followed quickly thereafter. The set is complete with Hemmi's two-toned plastic case, manual and original cardboard box. Note that Joe Soper identified many end of manufacture rules that had out of sequence parts, so rules made in the last year or so of production may have numbers that do not fit this chart. Such cursors can effectively double the accuracy of readings, permitting a 10-inch slide rule to serve as well as a 20-inch.
For painted slide rules, and the faint of heart, use diluted commercial window-cleaning fluid and a soft cloth. Cursor C is unpolished soft aluminum and essentially identical to B except that the frame around the glass is narrower and the inside frame corners are not rounded. Return to Page last updated on June 17, 2002 - All material © 1999, 2001 by Eric Marcotte, Ph. It does match the illustration of the 1937 H-O catalog, however. Magnifiying and decimal-indicating versions but not plain versions appear in the 1914 Hughes-Owens and the 1919 Tamaya catalogs.
These were catalog numbers, not model numbers; we don't believe that these numbers actually appeared on the rules. One can estimate dates of Hemmi slide rules from markings on the rules. An instruction manual for the unit marketed by Dietzgen can be found at All retrieved March 14, 2007. Hughes Owens 1771 - August, 1963 Here we go again. In this system, the last place in the catalog number indicated various combinations of case, instructions, and display boxes. Post itself actually made no slide rules; even those rules that bore the Post brand name were manufactured by others. Others feature scales for calculating.
K+E, Slide Rules from one of America's premier manufacturers! American Thesaurus of Slang: A Complete Reference Book of Colloquial Speech. Also around this time, they started engraving 2-letter date codes on all their rules representing the year and month they were made. This was especially useful for fractional powers. The ones that became catalog items can be tracked using the catalogs. These cursors are too varied to be described by any general principles but their slide rules usually carry date codes. Trig scales in degrees and decimals of degrees. All of it is explained in the manual included.
Instruction booklet is creased from fitting into box. While has reduced the use of for , and handheld have taken over many of its functions, the remains widely used as a primary or backup device and the majority of flight schools demand that their students have some degree of its mastery. Tom Dilatush has compared one to several old Faber cursors and is of the opinion that the design was copied from Faber. The slide rule made its first appearance in the late 17 th century. According to John Spivey's on Hughes Owens, the switch from the old 17xx series nomenclature to the new 341 xxx series took place between June and August 1964. Addition and subtraction are performed by sliding the cursor left for subtraction or right for addition then returning the slide to 0 to read the result. The last nail in the coffin for the slide rule was the launch of pocket-sized scientific calculators, of which the 1972 was the first.