23

G23

that the surprising result of a laboratory experiment might be connected
with the angular distance between two planets at the time,—he would,
on the average have to make some half million of utterly wrong conjectures
before he lit on the right one. But it is sufficient to consider
the time, labour, and expense that are generally required in order
positively to refute a respectable theory in physics, to convince
us that had the mind of man no decided tendency toward making
true physical conjectures physical science would never not in two or
three thousand years have made the brilliant start that it has made.