Page:Medical Heritage Library (IA b30513546).pdf/19

 But as to your present Questions, Madam, I will give you the most Satisfactory Returns I can.

And first, Madam, it will be necessary to acquaint you with the Meaning of the Word Globe; and what the Properties, in general, of such a Figure or Body, are.

Your Ladyship is to understand then, that a Globe is a round Body of such a Nature, that every Part of its Surface or Out-side, is at an equal Distance from one Point within it, which is called the Center. This Body also is sometimes named a Sphere, with regard to Astronomical Speculations; and this Science which you are now inquiring into, is hence called The Doctrine of the Sphere.

I understand you; laid she, the Figure of a Globe is not flattish like that of a Cheese or a common Ninepin Bowl; but rather like a Boy's Marble, or a Bullet cast in a Mould.

right, Madam, said I, and further you are to know, that a strait Line supposed to be drawn thro' the Center of this Globe any where, from one opposite Point of the Surface to the other, is called a Diameter.