Almost from its invention the barometer has been vaunted an indicator of impending weather, and now we are in possession of numberless rules for interpreting its indications, mostly of a vague and indefinite purport, few, if any, pretending to accuracy and certainty. As mankind are always desirous of attaining weather wisdom, these rules have tended to give the barometer its widely recognized reputation, rather than any really infallible principles, clearly formulated. With no other philosophical instrument have people so deluded themselves as with the barometer. Meteorology having become almost an official monopoly, the officials seem to have made the readiest and largest amount of reputation out of the barometer as a weather glass; for all that they have had to do is to compile rules from a number of authors, without any necessity of acknowledgment, print as much as they please at the Government expense, give it away freely, and the notoriety of authorship is secured easily and expeditiously. Thus the British nation has been officially supplied with about eighteen different editions of the Barometer Manual, widely differing from each other according to the views of the authors; for although the book remains the self-styled authors change, much the same as with the Cambridge books on mathematics. A study of the edition, "Coast or Fishery Barometer Manual," teaches that the barometer foretells coming weather; that it does not always foretell coming weather; that only few are able to understand much about what it does tell us; that it may be used by ordinary persons without difficulty; that its indications are sometimes erroneous: that any one observing it once a day may be always weatherwise; that its warnings do not apply always to the locality of the instrument; that storms frequently occur without its giving any warning; that barometer depressions happen with and without gales; and similar ambiguous or contradictory assertions ad nauseam. It is perfectly astounding to contemplate that official authority sanctions such inconsistent teaching, and moreover disseminates it far and wide, forcing its circulation by giving it away gratuitously on humane and eleemosynary grounds. Where only such confusing advice and direction can be given is it becoming to stamp it as official? it is lamentable inconsiderateness to expect fishermen to be able to dodge the weather by such guidance; and it is time to stop this easily concocted nostrum for notoriety; for it is vague and inconclusive in every precept, and has scarcely an assertion which is not contradicted by some other.--_Engineering._ A Remarkable Electrical Discovery.