Notes

In our Author's Lectiones Opticæ, Part I. Sect. IV. Prop 29, 30, there is an elegant Method of determining these Foci; not only in spherical Surfaces, but likewise in any other curved Figure whatever: And in Prop. 32, 33, the same thing is done for any Ray lying out of the Axis.

Ibid. Prop. 34.

See our Author's Lectiones Opticæ § 10. Sect. II. § 29. and Sect. III. Prop. 25.

See our Author's Lectiones Opticæ, Part. I. Sect. 1. §5.

This is very fully treated of in our Author's Lect. Optic. Part I. Sect. II.

See our Author's Lect. Optic. Part I. Sect. II. § 29.

This is demonstrated in our Author's Lect. Optic. Part I. Sect. IV. Prop. 37.

How to do this, is shewn in our Author's Lect. Optic. Part I. Sect. IV. Prop. 31.

See p. 59.

See our Author's Lect. Optic. Part II. Sect. II. p. 239.