Soon after the commencement of my astronomical studies, and whilst preparing for practical observation, I computed the Ephemerides of several years, from the continuous tables of Lansberg. Having followed up the task with unceasing perseverance, and having arrived at the point of its completion, the very erroneous calculation of these tables, then detected, convinced me that an astronomer might be engaged upon a better work. Accordingly I broke off the useless computation, and resolved for the future with my own eyes to observe the positions of the stars in the heavens; but lest so many hours spent on Lansberg should be entirely thrown away, I made use of my Ephemerides in ascertaining the positions of the distant planets, so that I was enabled to predict their conjunctions, their appulses to the fixed stars, and many other extraordinary phenomena. Delighted for the time with such a foretaste of the science, I took great pains carefully to prepare myself for further observation.

Whilst thus engaged, I received my first intimation of this remarkable conjunction of Venus with the Sun; and I regard it as a very fortunate occurrence, inasmuch as about the beginning of October, 1639, it induced me, in expectation of so grand a spectacle, to observe with increasd attention. I pardon, in the meantime, the miserable arrogance of the Belgian astronomer, who has overloaded his useless tables with such unmerited praise, and cease to lament the misapplication of my own time, deeming it a sufficient reward that I was thereby led to consider and to foresee the appearance of Venus in the Sun.