reason while there are only about a dozen registers complete for the four decades, there are thirty-eight which are complete for the last three decades. Now that we have found the relation between the first two decades, the returns for the thirty years are rendered almost as instructive as those for forty years.

We have therefore compiled Table IV., which differs from Table III. only in its being for thirty years instead of forty, and in giving observations from thirty-eight stations instead of twelve.

TABLE IV.-Comparison of the Rainfall in each Decade since 1839 with the mean Rainfall of thirty years ending 1869.

From the above Table the remarkable similarity of the results obtained by the two dissimilar modes of investigation is rendered so obvious that it

is unnecessary to dwell further upon it. We now proceed to the second part of our investigation, namely, to consider the distribution of the rainfall of the last decade, during which we have nearly four hundred perfect sets of observations. As each set of observations comprises more than a thousand entries, and the following Table contains the result of nearly half a million observations, it is probable that it contains some slight percentage of error, but we have no suspicion of the existence of any which appreciably affect the results.

The head-lines of the following Table sufficiently explain its contents.

TABLE V.—Mean Rainfall at 325 Stations during the ten years 1860–69.