1875.)  Selenography : its Past, Present, and Future. 223 
discovery may result ; but it cannot be too strongly urged 
that the hugest mass of isolated observations made without 
scope or character is far inferior in value to a well- 
considered series of observations made in pursuance of some 
definite plan and directed towards some distinct end. The 
former, it may be said, will serve as a mine from which, by 
labour, much may hereafter be extracted to confirm or 
disprove theories that may later be advanced; but even for 
this purpose they possess little value: for, to search through 
the mass for those observations that may be useful, with the 
almost certainty of finding them deficient in some especial 
feature necessary for them to be of real value in the 
particular direction warted, renders it easier to obtain the 
results required in a different manner. ‘The erection of an 
elaborate edifice, intended to be enduring upon an uncertain 
foundation, has long been recognised as unsatisfactory ; yet 
much of this chara¢teristic attaches to many selenographical 
hypotheses that have, especially of late, been promulgated. 
The origin of most of these may be ascribed to the vagueness 
incidental to desultory lunar observations, which, seldom 
pushed sufficiently far, often, as in other branches of science 
under similar conditions, afford untrustworthy results. Too 
much stress, therefore, cannot well be laid on the necessity of 
systematic series of observations being made, rather than 
mere desultory work, which seldom afford anything in value 
adequately representing the time and labour spent. 
Above all, it may again be reiterated, stands the necessity 
so often urged of the completion of the determination of the 
positions of the principal lunar formations that has, since 
the time of Beer and Madler, remained apparently untouched, 
despite the earnest appeals from the British Association 
Committees; when this has been successfully carried out, 
and the foundations for a thorough trustworthy aquaintance 
with the physical condition of the moon’s surface laid, then 
the detail can be filled in at leisure. Not until this is done 
can much success in solving the various selenographical 
questions be expected ; but then, in the words of our greatest 
selenographer, the late Baron von Madler, ‘‘may our 
satellite, after the monstrous fables which for almost the 
space of many thousand years have gained credence 
respecting it, begin, not only by its course, but also by 
its natural constitution, to permit us to pierce deeper into 
the secrets of the Fabric of the Universe! ”’ 
vol, V..(N.S.) 2F 
