Annual Reports of the War Department

FOG.

But little fog prevails during the months from October to April, inclusive. This form of cloud will be thoroughly examined with regard to its proportion to other cloudiness during the ensuing summer. A review of the reports proves the upper clouds, as well as the lower, to conform very frequently to the direction of the surface-current.

PHENOMENAL RECORD.-STORM-CENTERS OF BEHRING SEA AS CIRCULAR RESERVOIRS OF ELECTRIC FORCE.

The phenomeual record embraces observations on certain elements whose relations are still in comparative obscurity. The action of some unknown elements on the very texture of all clouds, under whatever phases they may appear, presents itself as a subject for close research and extended observations. Whatever may be the subtle nature of that which we designate electric force, and however this may be overladen with wandering, homeless theories, the most casual observer might, if thereto inclined, recognize the centers of all the southwest Pacific storms as vast reservoirs of electricity. These storm-centers, with their piercing hail, peculiar haze, and the wondrous density aud grandeur of their cumulo-stratus, offer certain and visible proof of electric action to a high degree, and form a secure base for attack on the primary causes of progressive movement. That a more thorough analysis of the attendant phenomena, assisted, if necessary, by magnetic and other apparatus, would result in more definite conclusions, is beyond a doubt.

AURORA POLARIS.

The atmospheric conditions over Behring Sea, in connection with the infrequency of the phenomenon now referred to, are particularly favorable for tracing auroral relations to storms.. Throughout all this area the cloudiness is so frequently broken that but few nights pass without rifts in magnetic north. The phenomenon, whenever it appears, is of very moderate intensity, and only under certain conditions is it visible at all, even through the clearest skies.

AURORAL RELATIONS TO ATMOSPHERIC ACTION.

The absence of aurora during the serene intervals of westerly quadrants of storms, the extension of peculiar luminous haze or electric light immediately preceding storms, and the diffused glow of the aurora discerned through rifts, or even dense clouds that accompany, are all relations constantly indicated by the journal and records. I doubt if a single storm has passed the island during the winter without the appearance, although perhaps obscured, of auroral light.

INCIDENTAL DEDUCTIONS.

It is, perhaps, rather foreign to logical or inductive conclusions, but a convincing proof, to my own mind, of a close connection between the aurora and atmospheric storm is, that whenever the display appears through a sky free from upper cloud I turn mechanically for the appearance of cirrus traces from beyond the Western Sea; and this quasi acknowledgment is more significant from the consciousness of having continued the winter observations without the slightest pre-determination.

ILLUSTRATIONS OF AURORAL RELATIONS.

With references at hand for the entire winter, I cannot but allude to the long period of inaction during the month of March. The heavens were sometimes partially and frequently almost clear, but no trace of aurora was visible, except on March 3; and how significant is the entry, in adjacent columns, that at this time the monotony was interrupted by those disturbers of atmospheric peace-the cirrus and cirro-stratus. After the termination of the long interval referred to the aurora, later in the month, was also visible in evident connection with storms, as entered in phenomenal record.

EVIDENCE OF Journal AND RECORDS CONCERNING AURORA.

The records of the entire season multiply these evidences; but lest future observations should fail to confirm the significance of the past, I have alluded to the aurora in this cursory manner, well aware that if the laws of atmospheric action and auroral phenomena are found to be intimately woven, the field of research, lying beyond this single but important premise, is still unbroken, although perchance quite as attractive as the visible phenomena that point it out.

HAZE-ITS RELATION TO STORM-CENTER.

Concerning the relations of haze, results from the storm-center induce certain immature suspicions that would scarcely coincide with any one of many accepted conclusions. I have entered observations thereon in phenomenal record, and, affixing a scale

of density, find that this element attains a great density only in or near a storm's central area. No evident relations between this haze of the center and the aurora have yet resulted-in fact, the latter phenomenon does not appear in a storm's focus. It is no less evident that there are relations, and those of an interesting nature.

GENERAL ELECTRIC PHENOMENA-OCEANIC AREA OF NON-DISPLAY.

This climatic area compares with all the continental western coast in freedom from thunder and lightning, of which there is no instance thus far recorded in reports. The area of the ocean and Behring Sea, in which these electric phenomena are extremely rare, has evidently no boundary on the north, extends as far as Petropauloosk on the west, and far into the Pacific Ocean on the south.

GENERAL PHENOMENA OF RECORDS.

Many other phenomena worthy of notice, however, have occurred during the winter. As an instance, a remarkable alternation between hail and snow, succeeded in the evening by aurora in connection therewith, is entered in journal of October 14, 1872. No one can turn the pages of such a continuous record without perception of disproportionate results; but, as meteorological investigation particularly demands, they are intended, I would repeat, for reference alone.

GENERAL REFERENCE TO RELATIONS OF OCEANIC AND CONTINENTAL STORMS.

The relations which the great storms prevailing over Behring Sea bear to those advancing over the continental interior are, by reason of the interposition of mountain chains, comparatively obscure. Those moving from a southwesterly direction precipitate heavily on the mainland coast, but whether their barometric waves penetrate the interior of British America, and thereby modify or act on those of the United States, is a question that, even were I already versed in the dynamic relations of storms, lies beyond the authority of this report to solve. I fear that simple allusion to these relations is premature, if not, forsooth, unwarrantable, assumption. Nevertheless, is it not possible that any one of the violent storms of that class from westnorthwest may, although yielding its moisture to the mountains, successfully advance its remaining forces over beyond those elevated chains, and then, forming a nucleus on the eastern plateaus, and gradually collecting new conditions of cloud and moisture, move forward to the Atlantic coast, retaining, as it were, the barometric life and interior causes of progression that originally forced the storm over the waters of the North Pacific?

Labyrinthian as these currents and waves of atmospheric action now appear, the secrets of their relations cannot be quite invulnerable. Analogous currents of the Atlantic Ocean and the dependence of European climate thereon open a route of inquiry which will doubtless penetrate any obscurity thrown over it by the configuration of our mainland coast.

The climate of St. Paul Island closely resembles that of the ocean district, of which Iceland is representative; and the day is evidently approaching when the vigorous growth of Pacific commerce and navigation will so encourage practical meteorology that a satisfactory reply can be given to the natural inquiry-Is the area north of the Atlantic Isles a key to any class of American storms?

I am, sir, very respectfully, your obedient servant,

The CHIEF SIGNAL-OFFICER, U. S. A.,

Washington, D. C.

CHAS. PATTISON FISH.