Versatile and cultivated
Andreas van Luchtenburg must have been a versatile and cultivated man. Besides being the city supervisor of Tholen, he taught the skill of plotting points and making measurements in the sky, the earth and the sea, and he was also a mathematician, an almanac calculator and a teacher of Italian and bookkeeping. But above all he was a man with a mind of his own who never kept his dissenting opinions to himself but published them in book form at his own expense.
Length of the solar year
For thousands of years, astronomers had tried to determine the length of the solar year as accurately as possible. The Gregorian calendar reform was based on a year of 365 days, 5 hours, 48 minutes and 20 seconds. Van Luchtenburg, however, was convinced that everyone had been wrong. He had measured the year at 365 days, 5 hours, 47 minutes and 9 seconds! But that was not his only deviation from the rest of the world. In 1582, Pope Gregory XIII had also decided that from then on, only the century years that were divisible by 400 could be leap years. Van Luchtenburg, however, insisted that according to his mathematical calculations, 1700 should also be a leap year. In this almanac, he has four people testify that his astronomical calculations are 'perfect'.
Because Van Luchtenburg's almanac uses a different Golden Number, his Easter falls on a different date: 3 May instead of 22 April. Neither could he leave the calculation of the solar and lunar eclipses to anyone else, since only he had determined the correct time for the 'tremendous solar eclipse' of 6 December 1695: from 6.55 to 9.07 a.m. Unfortunately that was a day of heavy clouds, so that no one was able to enjoy the solar eclipse anyway. Van Luchtenburg did call on all 'enthusiasts in the Netherlands and the bordering countries' to report to the newspaper if they were able to observe the eclipse.
His almanacs and prognostications attracted a great deal of criticism. The Dordrecht surveyor and almanac calculator Mattheus van Nispen wrote a pamphlet in 1700 entitled Aenmerckinge op en tegens de Eerste en Tweede nieuwe geinventeerde Almanacken van M. Andreas van Luchtenburgh over de Jaren 1699 en 1700 [Criticism of the First and Second newly invented Almanacs by M. Andreas van Luchtenburgh for the Years 1699 and 1700], in which he pokes fun at him. 'Sometimes the fool deserves a response fit for his folly'. He concludes by saying that Van Luchtenburg's almanac 'will find very little acceptance among the wise'. Indeed, in the year 2000 the Gregorian calendar has not yet been replaced by Van Luchtenburg's calendar. Until his death in 1709, Van Luchtenburg stubbornly continued to publish almanacs which stated on the title page that they 'retain, however, the faulty day-reckoning of 1700, since the world still insists on living in error'.
Andreas van Luchtenburg,Den opregten en noyt bekenden almanachfor 1696