SIDEREAL EXPLORATIONS1
INTRODUCTORY STATEMENT
IN the following pages I present an account of a series of
explorations. The quests are cosmographie rather than
geographic, and therefore differ widely from terrestrial ex-
peditions in equipment and aim; but there are some features
in common—the optimistic accounts of partial successes, the
complaints about obstacles, weather, and insufficient equip-
ment, and the suggestions of still more fascinating regions
down mysterious by-roads, or out beyond the horizon.
The report is concerned with the progress, throughout
eight regions, of researches which, considered in sequence,
exhibit our expanding knowledge of the sidereal universe.
The account concerns some of the plans for the future as
well as current work, and deals almost wholly with observa-
tions and studies that are carried on at the Harvard Ob-
servatory at Cambridge and at its southern station, formerly
in South America, now at Bloemfontein, South Africa.
The general line of attack on problems of galactic
measurement and analysis was outlined many years ago;
but only recently have we been able to proceed effectively
with explorations into all the territories included in the gen-
eral program. The survey extends from the nearest stars
of the Solar Neighborhood to the remotest nebulous patches
that we can photograph in our telescopic surveys of the
1Based on lectures given at the Rice Institute, March 9, 10, and 11, 1931,
by Harlow Shapley, Ph.D., Director of the Harvard College Observatory
and Professor of Astronomy in Harvard University.
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