TO JOHN LEE, ESQ., Q.C., LL.D., F.R.S., F.S.A., F.R.A.S., F.G.S., &c.

Summary

St. John's Lodge, 1—8—64.

My dear Friend,

Although the discoveries in sidereal astronomy since the advent of the elder Herschel, have been equally gratifying and marvellous, there is every prospect of still further triumphs for assiduity and observational skill to obtain. For this most desirable consummation, every department to which practical vigilance can render its aid, ought to be furnished to the utmost with sifted materials, in order that, from a mass of recorded facts, safe conclusions may be arrived at. This impression, together with the present number and efficiency of achromatic telescopes, induces me again to call attention to the still vague and indeterminate state in which the COLOURS of multiple stars are registered, with a word or two as to the steps for bettering it. In our confabulations on this material point we agreed, that a reprint of my former suggestions in a portable form, would probably attract the notice and suit the convenience of many observers; the present brochure was therefore undertaken to carry out this view.

The method which has hitherto been pursued in these examinations is both trite and inexact, having been mostly practised when the eye, at all times a delicate organ, has been fatigued by taking and reading-off measures made with an illuminated field; and some observers register the position and distance with the magnitudes of the objects, without a word as to their colours.