|Name and Model Number||Hemmi 405 |
Chemical Slide Rule
for Portland Cement
|Country of Origin||Japan|
|Date of Manufacture||1958 - 1959|
|Front Scales||7 scales - chemical compounds|
|Back Scales||7 scales - chemical compounds|
|Scale Length||25 cm|
|Type of Rule||Slide Rule|
|Construction||Celluloid on bamboo|
|Area of Use||Chemical|
|Comment||For Portland cement composition.
No logarithmic scales.
Instruction Manual published by Portland Cement Association, Skokie, Illinois, May 1959.
|Donor||Collection of Ron Knapp|
(Click Picture for Details)
|In conjunction with our 'donors' we assign a rarity rating to each item, based on the system devised by Herman van Herwijnen|
|(1929 - 2004), renowned Dutch collector, author, and creator of Herman's Archive, a collection of 5,000 slide rule images on CD.|
|• RR = Rare - 1 of 25 collectors has one; it may take a year to find an example in the marketplace.|
|• RRR = Very Rare - only a few known to collectors; may be several years before it comes up for sale.|
|• RRRR = Extremely Rare - a museum piece; unlikely that an example will come up for sale.|