Usually a generic name preceded by the form if not standard linear length - e.g. Pocket Enhanced Mannheim. For special models often supplemented by its function/use - e.g. meteorology. Sometimes a suffix is needed to distinguish between different versions - e.g. early or late.
||Heating requirements for rooms |
L/C/D/T/W/X where L=Linear, C=circular, D=Drum, T=tubular, W=watch, X=miscellaneous (i.e. the rest)
Basic construction form of the body i.e. Closed/solid frame or Open frame or Duplex or Other
Basic description: ivory/bone/wood/bakelite/plastic/metal/cardboard or combinations e.g. wood/veneered, wood/painted, etc
||Aluminium & plastic|
Mostly length in cm or ” (inches) of the D scale but excluding any scale extensions. But for circular or watch slide rules it is the diameter & for tubular or drum slide rules it is the overall linear scale length. For other mechanical aids it is the physical length.
|| Ø 15½ cm|
Mostly standardised (not maker’s) symbols for scales on front of stock e.g. A = X² (1-100) but § = generic symbol for any non-standard scale. Scales between solidi (/ /) are on the slide(s) whereas a vertical line ( | ) or reversed solidus ( \ ) + a symbol denotes scale(s) on a straight or bevelled edge.
|| §,§ / § / § / §|
Mostly standardised (not maker’s) symbols for scales on back of stock e.g. S = sine (5° to 90° & 85° to 0°) or sin(x) but § = generic symbol for any non-standard scale. Scales between solidi (/ /) are on the back of the slide(s).
Basic description (incl. material) + no. of hairlines, etc on any cursor(s) or alternative to a cursor - e.g. a stylus
||2 x plastic - 1 hairline|
Cn where n = 0-6 based on Herman van Herwijnen’s condition/quality scale
YYYY for year(s) of production or an approximation/range of years
Basic description of any accessories - e.g. case or stand + where relevant, an accreditation for image, etc
||thick fawn carboard wllet + template forms|
Details like “on back of rule” and/or language of instruction sheet/booklet - generic or instructions for common layouts usually not listed
||Dutch & German 4-page Guideline + 40-page manual in German + 5-page publisheed article in German|
Downloadable .PDF copy of unusual or uncommon model specific instructions
| Comments ||?
Any special or noteworthy traits + significant use-related facts + pertinent details of scales/tables in well of stock + any significant tables, etc on the back of the stock
® design by Ir. Ernest Gerber but clearly values obtained were internationally accepted norms for commercial projects - “bible” for heating industry - many nomograms compliment complex layout
MM-YYYY / MM-YYYY of the date added/left the collection or <YYYY if exact MM-YYYY no longer known