P-block staging entry validated for model fit. Imported from staging batch duell-thimm-p, source entry 1715.
Gelli gives the London Nisbet and Parker witness without a printed date and places it broadly between 1855 and 1860. The local 1860 witness remains the stronger working date, so Gelli is preserved only as a range note.
Vigeant confirms the London pamphlet and states that it summarizes principles taught by Bertrand.
The French-title and English-title London witnesses of 1860 were consolidated; the English edition is catalogued as 31 pages.