Chapter XX. Time and its Measurement.

PAGE
Difficulty of the Subject 438
Simultaneity . , 438
Units for measuring Durations (days, weeks, months, years) . . 439
The Civil Calendar (Julian, Gregorian, Ac.) 443
The Ecclesiastical Calendar (Date of Easter) 446
Day of the Week corresponding to a given date 449
Means of measuring Time 450
Styles, Sun-dials, Sun-rings 450
Water-clocks, Sand-clocks, Graduated Candles .... 453
Clocks 454
Watches 455
Watches as Compasses 457