Daniel Crouch Rare Books has released their Catalogue VI. Crouch specializes in maps, charts, atlases, globes and other cartographic items. However, this catalogue expands the boundaries a bit, focusing on calculating machines from the days long before the electronic calculators and computers we use today. It includes machines to help calculate latitude and longitude for those traveling the seas, or to read the stars, tell time and dates. The early seafarers needed access to this data, but with no GPS available, had to find other, clever ways. Many of these devices will still work today, though you may opt for simpler means when you travel. Here are a few samples of them.
We will start with an item reflecting the most important evolution in calendars, Theorica della Compositone dell'Universo et delle cause della Nuovo riforma dell'anno, from Antonio Carrarino. It is a single plate issued in the year 1582, the year of the introduction of the Gregorian calendar, in use to this day. Europe had been operating on the Julian calendar since the year 325, and while it provided for certain adjustments in time such as leap years, it did not fully account for shifting. The result was over the 12-plus centuries since its introduction, the spring equinox had shifted by 10 days, occurring on March 10. More than the timing of spring, it had shifted Easter from what was believed to be the proper time. Pope Gregory XIII set up a commission to fix the problem, with their new calendar being issued in 1582. It adjusted the occurrence of leap years going forward, but this still necessitated a major one-time change. Ten days had to be removed from the year to balance the centuries worth of drift first. Carrarino has provided an explanation of the changes and the need for them, as well as providing some helpful illustrations. A series of concentric circles displays the universe, with the sun in the middle, followed by the six planets (that's all there were then) with the moon sandwiched in, followed by the stars, universe, and the creator. Item 8. Priced at £16,000 (British pounds or $26,763 U.S. dollars).
As long as we have adjusted our calendars to accurately track days indefinitely, then a perpetual calendar should be good forever. Item 21 is a perpetual calendar designed by John Seller, circa 1680. It features a complex engraving by Seller fitted in a wooden frame. There are images representing the planets, time, death, a winged heart with a sword through it, perhaps representing repentance. Abbreviations for the days of the week are displayed in the center, with a volvelle featuring the numeric dates alongside. In case you share my ignorance of the meaning of the term “volvelle,” it is one of those moving wheels that you turn to advance the numbers forward. Seller calls them “rundles.” So, at the end of the week, you can advance the numbers by 7, so the new dates appear next to the days of the week. A second volvelle allows the months to be advanced as well. Crouch informs us that Seller had been found guilty of high treason in 1662, but managed to get pardoned and go on to conduct a business as a map and instrument maker. £15,000 (US $25,090).
Item 24 is an anonymous piece dealing with another issue of time, Der Grosse Stunden-Weiser aller Lander auff der gantzen runden Erd-Kugel, circa 1680. This is a broadside with a large circle in the middle. On the inside are two sets of roman numerals, 1-12, representing the hours of the day and night. Names of cities radiate out from the numbers at half hour intervals. This is something of an early map of time zones. However, this predates the development of actual time zones. Communities still used the sun as a basis for calculating time, so nearby communities could have times differing by just a few minutes from each other. It wreaked total havoc on railroad schedules once train travel became common. Timetables were not terribly meaningful when each community along the way was, in effect, in its own unique time zone. The result was the creation of 24 large timezones around the earth, with all communities within each zone recognizing the same time. Since this did not yet exist at the time this chart was created, the cities are broken out by half hour, and even there, the times would only be approximate. The early date of this piece left North America almost invisible. Time zones have cities from Latin America and the Caribbean except that California in America and New Sweden are listed. £3,500 (US $5,853).