VERTEBRATES
from lamprey to bird · and why "fish" and "reptiles" are not groups
MORSE CODE
26 letters and 10 digits · dot, dash
PHONETIC ALPHABET
the ICAO standard · for radio and telephone
THE BASKETBALL
four FIBA sizes with their circumference and mass — and why the rules set a bounce, not a pressure
FOOTBALL: THE BALL
Law 2, three codes of the game, five sizes and three FIFA quality marks — what a ball must survive
BALLS BY THE RULES
eleven sports at true relative size — circumference, mass, pressure, and who sets them
IMPERIAL UNITS
convert in your head · without a calculator
PAPER SIZES
the A series · from A0 to A6
SI PREFIXES
from quetta to quecto · twenty multipliers
BICYCLE CLASSES
frame, wheel by ISO 5775 and handlebar — three signs of a class, and what the frame is rated for
CAR CLASSES
segments A to F by length and bodies by box count — how to name any car you see
MOTORCYCLE CLASSES
rake, trail, wheelbase and seat height — six classes drawn at one scale