star from the centre of the Earth 4 semidiameters, which are these, the fifth and sixth, therefore it is more probable that the new star was elementary, than celestial.
Salv.You mistake the point; for if you note well it was not written, that the distance was exactly 4 semidiameters, but about 4 semidiameters; and yet you shall see that those two distances differed from each other many hundreds of miles. Here they are; you see that this fifth, which is 13389 Italian miles, exceeds the sixth, which is 13100 miles, by almost 300 miles.
Sagr.Which then are those few that agree in placing the star in the same situation?
Salv.They are, to the disgrace of this Author five workings, which all place it in the firmament, as you shall see in this note, where I have set down many other combinations. But I will grant the Author more than peradventure he would demand of me, which is in sum, that in each combination of the observations there is some error; which I believe to be absolutely necessary; for the observations being four in number that serve for one working, that is, two different altitudes of the Pole, and two different elevations of the star, made by different observers, in different places, Astronomical Instruments are very subject to errour. with different instruments, who ever hath any small knowledg of this art, will say, that amongst all the four, it is impossible but there will be some error; and especially since we see that in taking but one onely altitude of the Pole, with the same instrument, in the same place, by the same observer, that hath repeated the observation a thousand times, there will still be a titubation of one, or sometimes of many minutes, as in this same book you may see in several places. These things presupposed, I ask you Simplicius whether you believe that this Authour held these thirteen observators for wise, understanding and expert men in using those instruments, or else for inexpert, and bunglers?
Simpl.It must needs be that he esteemed them very acute and intelligent; for if he had thought them unskilful in the businesse, he might have omitted his sixth book as inconclusive, as being founded upon suppositions very erroneous; and might take us for excessively simple, if he should think he could with their inexpertnesse perswade us to believe a false position of his for truth.
Salv.Therefore these observators being such, and that yet notwithstanding they did erre, and so consequently needed correction, that so one might from their observations infer the best hints that may be; it is convenient that we apply unto them the least and neerest emendations and corrections that may be; so that they do but suffice to reduce the observations from impossibility to possibility; so as v. gr. if one may but correct a manifest errour, and an apparent impossibility of one of their obser-vations
