Again, the characters of the winds, and appearances at the different changes, are opposed to the circular theory. At a distance of fifty miles from the centre of a storm, the wind which passes over a ship as a southerly wind, will have made a rotation and a half, with the hurricane velocity, before the same wind can again pass the ship as a northerly wind, (supposing the progress eastward, and the ship lying to,) that is, the same wind which in another place was a south wind two hours before, and after only going one degree north, becomes a northerly wind,--changed in character and temperature, as every seaman is well aware. In a storm, if the circular theory be true, the character and temperature should be the same, no matter from what point the wind is blowing. This should be a conclusive argument. Mr. Espy has also changed his ground on the storms of the United States; he does not now contend that the winds blow inwards to a centre, but to a line either directly or obliquely. Thus we see that while Mr. Redfield concedes to Mr. Espy a spirally inward current, the latter also gives up a direct current to the centre, to Mr. Redfield. This shows at least an approximation to the truth. It is not necessary for the support of this theory, that we should derive any materials from the ruins of others; we shall therefore not avail ourselves of certain discrepant results, which can be found in many of the storms cited by Colonel Reid. With respect to Mr. Espy's _cause_ of storms, the experiments of Regnault may be considered as decisive of the question:--1st, because the specific heat of vapor is so much less than Espy assumed it to be; and 2d, because the expansion of air in a free space does not suffer any change of volume by ascending, except what is due to diminished pressure, and the natural temperature of that elevation. INDICATIONS OF A STORM.