PHASES OF THE MOON
eight phases · a full cycle of 29.53 days
$1.50
THE SOLAR SYSTEM
eight planets · size, distance, year and day
Free
SIZE CHARTS
shoes, tops, bottoms — and a centimetre under every grid
Free
SERUM ACTIVES
when to apply, what to keep apart in time, what the season changes
$1.50
MORSE CODE
26 letters and 10 digits · dot, dash
Free
PHONETIC ALPHABET
the ICAO standard · for radio and telephone
$2.50
THE BASKETBALL
four FIBA sizes with their circumference and mass — and why the rules set a bounce, not a pressure
Free
FOOTBALL: THE BALL
Law 2, three codes of the game, five sizes and three FIFA quality marks — what a ball must survive
$2.50
BALLS BY THE RULES
eleven sports at true relative size — circumference, mass, pressure, and who sets them
Free