Improvements in Perpetual Calendars.
Year: 1898

page_text: Date of Application, 1st Mar., 1898-Accepted, 9th Apr., 1898
COMPLETE DI MULTICATION
Improvements in Perpetual Calendars.
I, GEORGE DREYFUS, Merchant, of 32, Rue de Paradis, Paris, in the Republic of
France, do hereby declare the nature of this invention, and in what manner the
same is to be performed, to be particularly described and ascertained, in and by the
following statement:―
This invention has for its object an improved form of calendar permitting, with
the minimum of sheets or cards, all necessary combinations being obtained in a
rapid and accurate manner, to indicate the day of the week of a given date for any
year.
This perpetual calendar, which may be used for any year, consists in the grouping
on nine cards, that is on the minimum of separate cards; firstly, the figures
to 31 representing the date of the month, secondly, the names of the twelve months;
and thirdly the names of the seven days of the week.
The separate cards carrying these indications may be made of thick paper, card-
board, metal, celluloid or other opaque translucid or transparent material, which
may be luminous, that is, phosphorescent or not in the dark.
These square, rectangular, polygonal, circular, or annular cards are superposed
in such manner as to hide each other partially in order to partly cover the indica-
tions which they bear. The cards are held in a support of suitable material which
may be hung against a vertical or inclined surface, or can be stood upright or at a
suitable inclination on a writer's table.
The annexed drawing shows two types of perpetual calendar according to my
invention.
Fig. 1 shows a holder S with grooves a in which are superposed the various cards
making up a calendar indicating a day of the week for a given date and a given
month. This calendar is constituted by the superposition of nine cards or sheets:
First, two rectangular cards A carrying on the front and the back the names of
the seven days of the week, arranged at the top and bottom of the card and heads
outwards as shown in Figs. 1, 3 and 7; secondly, four square cards B carrying
on the front and back four numbers arranged in parallel, two by two, and heads
outwards. The whole of the printed figures, representing the days of the month
form the series of Figures 1 to 31, as shown in Figs. 1, 4 and 7; thirdly, three
rectangular cards C carrying on the front and back the names of the twelve months
printed heads outwards." At the bottom of each name of the month I have shown
the number of days of which it consists, in order to rectify any error arising from
the use of the monthly tables D) which each show 31 days. The cards C are shown
in Figs. 1, 2, 5 and 7.
To hide the names of the months placed heads outwards on the card C, I can
place between the grooves a, a cross piece, or arrange supplementary cards D which
cards carry at the back and front a table in which the numbers 1 to 31 are arranged
one under the other in vertical columns, opposite the names of the days of the week,
care being taken to place the number 1 opposite a different day in each table.
This table D, which is not indispensable, enables the exact dates of the month
under consideration to be given corresponding to any day of the week.
In the modification shown by Fig. 2 the grooved holder is arranged to receive

page_text: only the four monthly cards D and the three cards giving the names of the months.
This calendar, which only contains seven cards gives in an accurate manner the
exact date corresponding to a weekday for the month under consideration.
It is easy to understand that by moving these various cards, A BCD the date of
the month, day of the week, and the month are indicated for any date of any
year.
The grouping of these various cards may be varied, that is to say the card C of
the month may if required, be placed at the back of the holder S, instead of the
cards A giving the day of the week, the cards B giving the date being placed
thereon, by making these cards of the shape and size so that the marks they bear
may be partially covered, as shown by Fig. 7.
The sheets ABCD could rotate about an axis instead of sliding in the grooves a.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what I
claim is:-
1. A perpetual calendar constituted by a minimum number of separate super-
posed sheets carrying the names of the months, the days of the week and the dates
of the month capable of giving with accuracy the day of the week, the date and the
month for any day of any year, the said calendar being composed of rectangular
plates carrying at the front and back, heads outwards, the indications; some the
names of the months, others the names of the days of the week, and of square
plates carrying on the front and back four of the numbers 1 to 31 arranged in
parallel two by two and heads outwards.
2. A perpetual calendar formed of nine plates printed on the front and the back
and heads outwards of which two are rectangular for the days of the week; four
square, carrying the numbers 1 to 31 and three rectangular for the months. As
described and shown.
3. A perpetual calendar composed of seven plates printed on the front and back,
of which three are rectangular for the months printed heads outwards, and four
rectangular carrying, opposite the superposed names of the days of the week, the
Figures 1 to 31 arranged in vertical columns, the Figure 1 corresponding to a
different day of the week on each plate. As described and shown.
Dated this 1st day of March 1898
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.