EARLY LIFE IN NEW ZEALAND 31

during the whole history of the publication—already a
period of nearly thirty years. Against the prejudice of
his original suspicion, Rutherford concluded, " iron is
strongly magnetic in rapidly-varying fields, even when
the frequency is over 100,000,000 per second "—and,
as the result of the work described in the second paper,
" the iron did not take more than 10Q00 of a second
for the rearrangement of the molecules into their final
position, so that there is no appreciable time-effect
in the demagnetization of finely-laminated iron".
It is clear from the wording of these conclusions that,
in detail, the experiments had to do directly or in-
directly with effects occurring in very short intervals of
time, and it is probably correct to say that the most
surprising part of a very singular achievement was the
way in which Rutherford was able to estimate directly
such small fractions of a second as were involved in this
work. The " time apparatus ", to which he had already
devoted some thought during his year as an honours
student in the physics laboratory, was essentially a
mechanical contrivance of levers and falling weights of
great simplicity. But, by careful attention to details, it
was made to give good results.

During the course of the first of the two papers already
mentioned, we come upon the general remark, " It
has been shown how a magnetized steel needle placed
in a small solenoid may be used as a detector of an
oscillatory discharge, and also as a means of determining
the rate of decay of the oscillation." This was the
starting point from which Rutherford began to take a
practical interest in the transmission and detection of
electromagnetic, Hertzian—or, as we should now say,
" wireless "—waves. In 1887 Hertz had been the first
to show that effects were radiated into space from