Two rectangular calendar cards. Bottom calendar card with 24 blocks of dates. Letter scales along top and bottom edges. Verso plain. Top card pierced with 12 windows for months. With table assigning a key letter for each year from 1761 to 2284. Edge of card has arrow. By shifting top card's arrow with respect to letter scale along edge of lower card, the proper calendar for the entire year appears in the monthly windows. Recto for leap years; verso for non-leap years.
Matériel
"(Copyright registered in Canada; No. 70991, June 17, 1946--R.H.M. Falls, Montreal, Que.)".
