PREFACE 
The idea of compiling this History was started some years before 
the Centenary. A Committee was appointed to deal with the 
matter, and it was decided to distribute the work among ten 
Fellows of the Society, each being responsible for one decade. 
It was hoped that by beginning thus early the different collaborators 
would be able to collect materials in a leisurely manner. But the 
best scheme has its drawbacks, and it is a familiar fact that having 
plenty of time may result in being late after all. Moreover, in 
some cases those who had undertaken a share found that their 
hearts failed them, and it is due to the untiring assistance of 
Dr. Dreyer, who came to the rescue, that the scheme has been 
finally carried out in a somewhat modified form. Not only has 
Dr. Dreyer dealt in all with fifty years out of the hundred, but he 
has acted as co-editor for the whole, and if I venture to sign my 
name to this preface as original editor, it is chiefly in order that 
I may express more fully my grateful thanks to him for all that 
he has done, which included the important but tiresome under 
taking of compiling the index. 
The list of independent authors ultimately stands as follows :— 
1820-1830, 
H. H. Turner . 
. pp. 
• 99 
I-49 
1830-1840, 
J. L. E. Dreyer 
50-81 
1840-1850, 
R. A. Sampson 
• 99 
82-109 
1850-1860, 
E. H. Grove-Hills 
• 99 
IIO-128 
1860-1870, 
H. F. Newall . 
• 99 
I29-166 
1870-1880, 
H. P. Hollis . 
• 99 
I67-2II 
1880-1920, 
J. L. E. Dreyer 
• 99 
212-249 
It was almost inevitable that in spite of every desire to the 
contrary some things should be overlooked until too late. One 
or two points concerning the early years were caught in time to 
add them on pages 48 and 49 ; but the later limit also brings its 
difficulties. The century of which this is the history closed at a 
time when the Society was again in full vigour and growth after 
the difficult years of the great war, and some things which 
occurred after the limiting date were the natural outcome of those 
which preceded it. Thus it seems proper to mention, even though 
only in a footnote, the generous donations prompted by the 
deplorable effects of the war on our finances ; and the very sight 
of this note (on p. 246) suggested (although too late for proper 
treatment in that place) that the noble bequest of a library of 
early mathematical and astronomical books, with £250 towards 
the expenses of housing them, which we owe to the late Colonel 
y