|Name and Model Number||System Tombeur, Basic - Prototype|
|Country of Origin||England|
|Date of Manufacture||2012|
|Front Scales||A [C] §|
|Scale Length||244 mm|
|Type of Rule||Slide Rule|
|Construction||Mahogany, Paper, Perspex|
|Area of Use||Other|
|Comment||Handmade forerunner of System Tombeur Basic slide rules for jugglers.
Designed and made by Colin Tombeur.
|Donor||Collection of Colin Tombeur|
|RR||= Rare -- 1 of 25 collectors has one; it may take a year to find an example in the marketplace.|
|RRR||= Very rare -- only very few known to collectors; may take several years before one comes up for sale.|
|RRRR||= Extremely rare -- a museum piece; unlikely that an example will ever come up for sale.|