Now, there are, as we have seen, peculiar, distinctly-marked varieties of cloud, connected with peculiar and distinctly-marked conditions of the atmosphere, _irrespective of temperature_. None of the theories advanced, account, or profess to account for the differences in either. No modification of the calorific theory will account for them. They differ in shape, in color, in tendency to precipitation, in line of progress, and in electrical character. The explanation of this is found in the fact, that they form in distinct and different strata, partake of the positive electric character of the one, or the negative of the other; or are secondary, induced by the action of a primary condensation in a different stratum. There is not any mingling of the different strata, as has been supposed; and many other facts than those to which we have alluded, show that the formation of cloud is a magneto-electric process. The observations of Reid show that every violent shower cloud has the electricities disturbed, and portions of it are positive, and others negative. Howard gives us the following _resume_ of Reid's observations: "From an attentive examination of Reid's observations I have been able to deduce the following general results: "1. _The positive electricity, common to fair weather, often yields to a negative state before rain._ "2. _In general, the rain that first falls, after a depression of the barometer, is_ NEGATIVE. "3. _Above forty cases of rain, in one hundred, give negative_ electricity; although the state of the atmosphere is positive, before and afterward. "4. _Positive rain, in a positive atmosphere, occurs more rarely_: perhaps fifteen times in one hundred. "5. _Snow and hail, unmixed with rain, are positive, almost without exception._ "6. _Nearly forty cases of rain, in one hundred, affected the apparatus with both kinds_ of electricity; sometimes with an interval, in which no rain fell; and so, that a positive shower was succeeded by a negative; and, _vice versa_; at others, the two kinds alternately took place during the same shower; and, it should seem, _with a space of non-electric rain between them_." Howard attributes, with great apparent probability, the successive differences in the electrical character of the rain, to the passage of different portions of the cloud, having different polarity, over the place of observation. So _positive hail_, and _negative rain_ fall in _parallel bands_ from the same cloud. Many such instances are on record. It should be remembered that he is describing the phenomena in the showery climate of England.