rs sailed by chance. If they happened to get into the belt of
wind that suited them, their voyages were favourable; if they got into
the wrong region, their voyages were unfavourable,--that was all. But
they had no idea that there was any possibility of turning the tables,
and, by a careful investigation of the works of the Creator, coming at
last to such knowledge as would enable them to reduce winds and waves,
in a great degree, to a state of slavery, instead of themselves being at
their mercy.

The world may be said to be encircled by a succession of belts of wind,
which blow not always in the same direction, but almost invariably with
the same routine of variations. A vessel sailing from north to south
encounters these belts in succession. To mariners of old, these varying
winds seemed to blow in utter confusion. To men of the present time,
their varied action is counted on with some degree of certainty. The
reason why men were so long in discovering the nature of atmospheric
circulation was, that they were not sufficiently alive to the immense
value of united effort. They learned wisdom chiefly from personal
experience--each man for himself; and in the great majority of cases,
stores of knowledge, that would have been of the utmost importance to
mankind, were buried with the individuals who had laid them up.
Moreover, the life of an individual was too short, and his experience
too limited, to enable him to discover any of the grand laws of Nature;
and as there was no gathering together of information from all quarters,
and all sorts of men, and all seasons (as there is now), the knowledge
acquired by individuals was almost always lost to the world. Thus men
were ever learning, but never arriving at a knowledge of the truth.

May we not here remark, that this evil was owing to another evil--
namely, man's ignorance of, or indifference to, the duty of what we may
term human communication? As surely as gravitation is an appointed law
of God, so surely is it an appointed duty that men shall communicate
their individual knowledge to each other, in order that the general
knowledge of the species may advance and just in proportion to the
fidelity with which men obey this duty--the care and ability with which
they collate and systematise and investigate their knowledge--will be
the result of their efforts.

In order to make the above remarks more clear as regards atmospheric
phenomena, let us suppose the case of