vm

PREFACE.

presented these last-named views to the Society; to Mr. Trouvelot , whose drawing of Saturn is shown in Plate IX.; toMr. Nasmyth, for the plate of the lunar mountain, Copernicus ;to Mr. G. F. Chambers, for ten woodcuts (six of which arefrom his “ Handbook of Descriptive Astronomy ”), and forpermission to reproduce two others ; to Messrs. Kegan Paul ,Trench, & Co., who have kindly supplied the copies of aphotograph of the Moon , by Mr. Rutherfurd ; to Mr. W. H. Wesley , the Assistant Secretary of the Royal Astronomical Society , for invaluable assistance in the preparation of nearlyall the woodcuts, and of Plates II., III., VII., VIII., and IX.”;to Mr. W. T. Lynn, who has carefully revised the proofsheets, and whose suggestions whilst doing so have not onlymuch contributed to the accuracy of the statements made inthe volume, but have atforded important additions to its infor-mation. The kind assistance of many other friends has alsobeen most helpful.

“ With what a perfect, world-revolving power,

Were first th’ unwieldy planets launch’d alongTh’ illimitable void ! Thus to remainAmid the flux of many thousand years,

Unresting, changeless, matchless, in their course ;

To night and day, with the delightful roundOf seasons, faithful ; not eccentric once :

So pois’d, and perfect is the vast machine ! ”

Gresham College ,

October, 1882 .