Finally, attention will be paid to 'a recent peculiarity which will lend special value to observations made in the eclipse of June 19, It is known that solar phenomena come in a cycle of sbout eleven years, This cycle shows itself by a variation in the number and position of sunspots. At the beginning of the cycle, the solar latitudes, between 30 degrees. above and below the equator, After four or five years, there is a growth in the number of sun-spots which seem {o come down more and more towards the equator. During the following six or seven years, the spots begin to diminish in number, Dut come farther down towards the equator, until they reach @ minimum, point, when they re-appear in the higher altitudes.
This cycle Is therefore composed of two unequal parts, the period of increase being short, and the period of decrease longer. Moreover, this cycle, with its two parts, appears in other phenomena, either solar (prominences, faculae, and forms of the corona) oF ferrestial (aurora borealis, terrestrial magnetism and {ellurie currents), Much Longer Cycle But a recent study tends to show the existence of another solar period of about 100 years which Is comprised of nine cycles of eleven years, with one additional been that the inst solar cycle seems fo have been calculated at between 1923 and 1983 (minimum years) and the preceding cycle between 1913 and 1923. "One therefore has two cycles of only ton years which were much shorter than the average and it appears as if the same phenomenon occurred in 1823 and in 1723." This curious exception will perhaps' mant-fest itself in the appearances of the corona. We are in the middle of the, period' of solar activity and. the observations will, therefore, be most Interesting. 3
Text read from the printed page and cleaned; old type leaves the occasional error.