Galilei, Galileo Dialogues on two world systems 1661, tr. Salusbury, Thomas

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276

And bringing back the Parallax 0 gr. 8 m. 30 sec. to 7 gr.
7 m. whose sine is 204, the star elevateth to 30 semidiameters or
thereabouts; therefore the correction of 0 gr. 1 mi. 30 sec. doth
not suffice.

Now let us see what correction is requisite for the third work­
ing made upon the observations of Hainzelius and Tycho, which
rendereth the star about 19 semidiameters high, with the Pa­
rallax of 10 m. pri. The usual angles and their sines, and chord
found by the Authour, are these next following; and they re­
move the star (as also in the Authours working) 19 semidia­
meters from the centre of the Earth. It is necessary therefore for
the raising of it, to diminish the Parallax according to the Rule
which he likewise observeth in the ninth working. Let us there­
fore suppose the Parallax to be 6 m. prim. whose sine is 175, and
the division being made, there is found likewise lesse than 31
semidiameters for the stars distance. And therefore the correcti­
on of 4 min. prim. is too little to serve the Authours purpose.