• 455 Martinson, Los Angeles
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  • Ruxton Multi-Vider drop-lead pencil & slide rule
  • Rare Otis King Model K - white scales on black background
  • Pocket Hexadecimal Slide Adder for Computer Programmers
  • Post 1824 Dring & Fage Alcohol Gauging Rule
  • Darnley’s Rotable Lightning Calculator/Pencil Case
  • Lawrence Antenna (classified by UK & US during WWII) for Radar Beam Pattern Detection
  • Makeba Kombinator pencil & slide rule
  • Rare Carbic-made Fischer Calculator
  • For Calculating Strength of Liquids in Twaddells !!
  • PTT rule for Cable Radio (Signal Loss/dB)
  • Smallest drum (≈ 2.4m) made by LOGA

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You searched for: Dennert & Pape
DUPA S.90 Rietz wood/celluloid veneers

Possibly an early special commission for H. Linke - PERTODO = D&P trademark for free-view cursor (they wanted RERTOTO from the Latin word “totus” but had to change to PERTODO) - 4 adjustment screws on botton side edg​e - conversion tables on back

GWR Desktop Military Naval Artillery plastic

Instruments for German armed forces used codes to hide maker’s identity - GWR​ = D&P - besides solving normal artillery-related distance problems, this naval version also takes into account drift of a moving vessel

Dennert & Pape GWR Desktop Military Naval Artillery
I Enhanced Mannheim wood/celluloid veneers

Railway track scales + cm scale & D&P Altona & “Patent” in well of stock - conversion table on back

IV Desktop Enhanced Mannheim wood/celluloid veneers

IV = model with 4 adjustment screws in bottom edge - railway track scales - cm scale in well of stock​

QR 41 Desktop Military Artillery Squaring plastic

QR = “Quadrat-Rechenschieber” - commissioned by “Gebr. Wichmann” (stamp in well) - probably classroom training aid for anti-aircraft gunners - layout consists of two pairs (upper set 0 - 50 & lower set 0 - 15.8) of non-logarithmic independent root scales (no interaction) derived from a set of tables by German Peter Timpenfeld & first published in 1888​ - non-conventional use of a cursor purely for positional summing of the squared values

Dennert & Pape QR 41 Desktop
System Rietz Rietz wood/celluloid veneers

DRP No. 126499 in well of stock + conversion tables on back​

DUPA Line Loss & Voltage Drop Calculator Electro poly-slide (2) wood/celluloid veneers

Copyrighted & patented (US1560599) by Charles C. Moler in 1925 - special commission for The Potomac Edison Company, Maryland, USA (Moler’s employer) ​- 4 adjustment screws in top side edge - besides preventing voltage flicker on electrical distribution lines it could save money by avoiding a higher grade of cable than really needed

Dennert & Pape/DUPA Line Loss & Voltage Drop Calculator Electro
Präzisions-Kubus-Rechenstab Squaring long-scale wood/celluloid veneers

Uncommon & unusual model with just root & trig scales (all long scales) - one open window with cursor line in back on right​ ​

Dennert & Pape/DUPA Präzisions-Kubus-Rechenstab Squaring long-scale