Popular opinion has ever attributed to the moon a controlling effect upon the changes of the weather. If it be dry, a storm is expected _when the moon changes_; or if it be wet, dry weather. Such popular opinions are usually entitled to respect, and founded in truth. But every attempt to verify _this opinion_, by careful observation and registration, has failed. Weather-tables and lunar phases, compared for nearly one hundred years, show four hundred and ninety-one new or full moons attended by a change of the weather, and five hundred and nine without. The celebrated Olbers, after _fifty years of careful observation_ and comparison, decided against it. So did the more celebrated Arago, at a more recent date--summing up the result of his observations by saying--"Whatever the progress of the sciences, never will observers, who are trustworthy and careful of their reputation, venture to foretell the state of the weather." Still, the moon may influence the weather, though she may not effect changes at her syzygies or quadratures, and this subject should not be too summarily dismissed. That the moon can not effect changes at the periods named seems philosophically obvious. She changes, for the _whole earth_, within the period of twenty-four hours; yet, how varied the state of things on different portions of its surface. The equatorial belts of trades, and drought, and rains, cover from fifty to sixty degrees of its surface, and know nothing of lunar disturbance. The extra-tropical belt of rains and variable weather moves up in its season, uncovering 10 deg., or more, of latitude, and admitting the trades and a six months' drought over it, as in California, regardless of the moon. Under the zone of extra-tropical rains, even upon the eastern part of the continent of North America, "dry spells" and "wet spells" exist side by side; the focus of precipitation is now in one parallel, and now in another--_storms_ exist _here_ and _fair weather there_, on the same continent at the same time; and as the moon's rays in her northing pass round the northern hemisphere during the twenty-four hours, they, doubtless, pass from ten to thirty or more storms, of all characters and intensities, moving in opposition to her orbit--and as many larger intervening areas of fair weather, not one of which are indebted to her for their existence, or "take thought of her coming."