Abstract
The subject should be taught so as to be of use both to users of optical instruments and also to designers. The course should be mainly Gaussian optics with only a qualitative exposition of aberrations. Much more design work of a Gaussian character ought to be done, particularly with the view of ensuring requisite diameters to lenses. Examples of optical systems should include more modern instruments and not be virtually confined to the astronomical telescope. There is scope for a far greater development of the analysis and design of reflecting prism systems.