Pickett Model B-1

The Model B-1, the only Pickett rule manufactured with bamboo covered with white celluloid and scales engraved on, began to be fabricated in Japan by the Relay-Ricoh Company, during the 1960's., conclusion I make based in the logo style on the rule, the one used from 1964-1975. Why the great manufacturer of metallic slide rules decided to create this rare specimen? It is still a mystery, at least for me. No other bamboo rule has the Pickett logo engraved on. I have not found a book or other extensive source about the Pickett company history, so, it is only possible to speculate about the reason(s) behind the production of this item. Market expansion to the wood- bamboo slide rules market? By the same time Keufell & Esser was moving out of the wood slides rules to the plastic rules with the production of the Deci-Lon model. Was the B-1 thought to fill the gap left by K&E?

By the other hand, the B-1 is practically identical to the Sans & Streiffe 312, also fabricated by Relay-Ricoh, the only difference is the two scales to calculate square roots instead the DI and P scales on the 312 model, plus the labeling at both ends of the scales. This can be considered a rule for engineering applications, and a natural question is, Was this considered an alternative to the magnesium Model 3 produced in the 1940's ?

The 25 scales set on the B-1 rule are distributed in the next way; on the front side -> LL0, L, A [ B, Cos S, SecT ST, T T, C ] D, sqr1, sqr2, LL0, and scales LL1, LL2, LL3, DF [ CF, CIF, CI, C] D, LL3, LL2, LL1 on the back side.

Engraved on the edge of the rule is the code rs-6, that makes reference to the fabrication year, and according with the three-characters codes production date used by Relay-Ricoh, deciphered by Paul Ross in his Journal of the Oughtred Society article: Relay/Rico Slide Rules, and shown in this ISRM page, it seems that the item in this collection was manufactured in 1969, what is consistent with the logo style on the rule. And this fact makes think that one of my references is possibly not correct. The ISRM Pickett's page shows a B-1 referred c.a. 1950, but the rule has the last logo style used by Pickett, not the one used in the 1950"s

Next are compared the Pickett B1 and the Sans&Streiffe 312. It can be seen that there is no a big difference:

Click on the next links to see professional panoramic pictures of the B-1 model.

https://www.sliderulemuseum.com/Pickett/S186_Pickett_B-1.jpg

References;

Ross, Paul: Relay/Ricoh Slide Rules, Journal of the Oughtred Society. https://osgalleries.org/journal/pdf_files/9.2/V9.2P64.pdf