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Appendix II.

other; whereas they ought to coincide, ofthe Glasses should be so placed before theEye in two Planes equally inclined, thattheir Axes may both unite in the Object towhich the Eye is directed, and they become■one with the Axis of the Eye. To illuf-Fig. 5. 'irate this, let A B be the two common- SpeEtacle-GlaSes-, whose Axes A C and B Vare parallel, and thereby directed to Ob-jects only at an infinite Distance, quitecontrary to the Design of these Glasses,which is to shew a near Object, as suppossG; then the Glasses E, F, are so placed inthe new visual Form as to have their Axestending to, and uniting in that Point G )by which Means they become coincidentwith the Axis of the Eye, and the Rays ofLight are regularly and equally refracted'to the Pupil. And consequently the Visionor Appearance of an Object will by thisMeans be rendered the most natural and-easy that it possibly can be; and indeed theDifference is so considerable, not only I stitself, but likewise by Experience,, that Im ay venture to prognosticate, that in ,afew Years Time, after the Aversions whisharile from Custom, Interest, and Noveltyare worn off, the common SpeSlacles wsdbe looked upon as the Opprobrium of the