Reverting to the explanation of the words on the "Coast" barometers (at page 14), and comparing and considering them as given for northern latitudes, and as they must be altered for southern latitudes, it will be perceived, that for all _cold_ winds the barometer rises; and falls for _warm_ winds. The mercury also falls for _increased_ strength of wind; and rises as the wind _lulls_. Likewise before or with rain the column of mercury falls; but it rises with fine dry weather. Putting these facts together, and substituting for the points of the compass the terms "cold" and "warm," the appropriateness of the words on the scale of this barometer is readily perceived. These concise and practical indications of the movements in the barometer are applicable for instruments intended for use in any region of the world, and are in perfect accordance with the laws of winds and weather deduced by Dove and other meteorologists. There is nothing objectionable in them, and being founded upon experience and the deductions made from numerous recorded observations of the weather in all parts of the world, as well as confirmed by the theories of science, they may consequently be considered as generally reliable. They involve no conjecture, but express succinctly scientific principles. =24. Trials of the FitzRoy Marine Barometer under Fire of Guns.=--Some of the first barometers made by Messrs. Negretti and Zambra on Admiral FitzRoy's principle were severely tried under the heaviest naval gun firing, on board H.M.S. _Excellent_; and under all the circumstances, they withstood the concussion. The purpose of the trials was "to ascertain whether the _vulcanized india-rubber packing_ round the glass tube of a _new marine barometer_ did check the vibration caused by firing, and whether guns might be fired close to these instruments without causing injury to them." In the first and second series of experiments, a marine barometer on Admiral FitzRoy's plan was tried against a marine barometer on the Kew principle, both instruments being new, and treated in all respects similarly. They were "hung over the gun, under the gun, and by the side of the gun, the latter both inside and outside a bulkhead,--in fact, in all ways that they would be tried in action with the bulkheads cleared away." The result was that the Kew barometer was broken and rendered useless, while the new pattern barometer was not injured in the least. In a third series of experiments, Mr. Negretti being present, five of the new pattern barometers were subjected to the concussion produced by firing a 68-pounder gun with shot, and 16 lbs. charge of powder. They were suspended from a beam immediately under the gun, then from a beam immediately over the gun, and finally they were suspended by the arm to a bulkhead, at a distance of only 3 ft. 6 in. from the axis of the gun; and the result was, according to the official report, "that all these