INTRODUCTORY CHAPTER. 
41 
intensity and frequency, lasting about eleven years; 
and these variations seem to coincide with the varia¬ 
tions in the number and importance of the spots on 
the sun, which also run through cycles of about 
eleven years. According to Mr. Meldrum the cyclones 
of the Indian Ocean also occur in eleven yearly cycles, 
during which their frequency and strength coincide 
with the condition of the solar spots. He also infers, 
from a careful examination of the meteorological re¬ 
ports of various places, that in the countries surround¬ 
ing the Indian Ocean, such as Ceylon, Mauritius, 
Adelaide, &c., the rainfall periodicity corresponds 
with the cyclone periodicity; and that the years of 
maximum rainfall correspond with the years of maxi¬ 
mum sun-spot frequency, while the years of minimum 
sun-spot frequency are those of minimum rainfall. 
These remarks suggest that the observation of the 
climatic and telluro-magnetic elements in Polar 
regions would lead to results of the highest scientific 
importance, which would also be of great practical 
benefit. This object alone should be a sufficient 
answer to those who want to know what use there 
may be in Polar research. The scientific man knows 
that no well-conducted inquiry is useless; and that 
the electric telegraph, the steam-engine, the galvanic 
battery, and numerous other inventions of unques- 
