Page:Mathematical collections and translations, in two tomes - Salusbury (1661).djvu/374

This page has been proofread, but needs to be validated.
Dialogue. III.
347

spake not friendly, when you said you did not know that same fallacy which you now confesse that you know very well.

Sagr.The very confession of knowing it may assure you that I did not dissemble, when I said that I did not understand it; for if I had had a mind, and would dissemble, who could hinder me from continuing in the same simulation, and denying still that I understand the fallacy? I say therefore that I understood not the same, at that time, but that I do now at this present apprehend it, for that you have prompted my intellect, first by telling me resolutely that it is null, and then by beginning to question me so at large what thing that might be, whereby I might come to know the station and retrogradation of the Planets;The station, direction and retrogradation of the Planets is known, in relation to the fixed stars. and because this is known by comparing them with the fixed stars, in relation to which, they are seen to vary their motions, one while towards the West, and another towards the East, and sometimes to abide immoveable; and because there is not any thing above the Starry Sphere, immensely more remote from us, and visible unto us, wherewith we may compare our fixed stars, therefore we cannot discover in the fixed stars any foot-steps of what appeareth to us in the Planets. This I believe is the substance of that which you would force from me.

An Indice in the fixed stars like to that which is seen in the Planets, is an argument of the Earths annual motion.Salv.It is so, with the addition moreover of your admirable ingenuity; and if with half a word I did open your eyes, you by the like have remembred me that it is not altogether impossible, but that sometime or other something observable may be found amongst the fixed stars, by which it may be gathered wherein the annual conversion resides, so as that they also no lesse than the Planets and Sun it self, may appear in judgment to bear witnesse of that motion, in favour of the Earth; for I do not think that the stas are spread in a spherical superficies equally remote from a common centre, but hold, that their distances from us are so various, that some of them may be twice and thrice as remote as others; so that if with the Telescope one should observe a very small star neer to one of the bigger, and which therefore was very exceeding high, it might happen, that some sensible mutation might fall out between them, correspondent to that of the superiour Planets. And so much shall serve to have spoken at this time touching the stars placed in the Ecliptick.The fixed stars without the Ecliptick elevate and descend more or lesse, according to their distance from the said Ecliptick. Let us now come to the fixed stars, placed out of the Ecliptick, and let us suppose a great circle erect upon [i. e. at right angles to] the Plane of the ** i. e. of the Ecliptick. same; and let it, for example, be a circle that in the Starry Sphere answers to the Solstitial Colure, and let us mark it CEH [in Fig. 8.] which shall happen to be withal a Meridian, and in it we will take a star without the Ecliptick, which let be E. Now this star will indeed vary its elevati-

on