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1855, February 8, Nova Scotia, New Brunswick, and New England

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1856, May 1, CANADA.-At Ottawa and its vicinity, (See Canadian Nat. Vol. I).

1857, October, " In the Upper Province.

1858, January 15, CANADA.-At Niagara, slight.

"L May 10, แ At Richmond, slight. "June 27, New England.-At New Haven, slight. 1859,

CANADA.-At Metis.

On comparing the above table with the deductions of Mallet and Perry for the entire globe, we perceive the applicability to Canada of the law ascertained by them, that the greatest and most frequent shocks occur a little after the middle and toward the close of each century. Thus in Canada and New England the years from 1658 to 1663, from 1756 to 1766, and from 1791 to 1796, were periods of special seismic activity, and in the present century our most severe shock has been in 1860, and judging from the previous centuries will no doubt be followed by others.

With respect to seasons of the year, the published catalogues show that January presents the maximum, and May and June the minimum activity for the northern hemisphere, and that the autumn and winter months are those in which earthquakes occur most frequently. Nearly in accordance with this, in the above list the earthquakes are distributed as follows:

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We have only to add that the present article is to be regarded only as an imperfect and hasty summary, and that we shall gratefully receive and publish, in a supplementary article, any informa tion which our correspondents may supply respecting either the late earthquake or any of its predecessors.

J. W. D.

ARTICLE XLVII.-The Meteor of July 20, 1860, by C. S. LYMAN. From Silliman's Journal, September, 1860.

This remarkable meteor was visible over a portion of the earth's surface at least a thousand miles in length, (N. N. W. to S. S.E.)

by seven or eight hundred in width; or from Lake Michigan to the Gulf Stream and from Maine to Virginia. The newspapers have contained many notices of its appearance as seen at various places within these limits, but most of these accounts are too vague to be of any scientific value. We are not yet in possession of a sufficient number of good observations for a final discussion of the phenomena presented, and can only at this time notice briefly a few of the best that have come to hand, and state some approximate results derived from them respecting the height of the meteor above the earth, the direction of its path, &c.

At New Haven, it was seen, during a portion of its flight, by several members of the Scientific Faculty at the house of Prof. J. A. Porter, and pains were at once taken to fix its apparent path by reference to parts of the building, tree-tops, stars, &c., near which it had been seen, and also to determine its time of flight, by noting the time required to repeat the various acts performed while it was in sight. The bearings and altitudes of the points noted for fixing the path were subsequently determined instrumentally. Independent data of the same kind were also obtained by going with many different observers to the places occupied by them at the time, and observing with compass and quadrant the path in the sky pointed out by each, and noting the time for each in the manner already indicated.

By laying down these bearings and altitudes on a globe, a normal or average path was obtained, which cuts the horizon at N. 62° W. and S.. 62° E., and gives a maximum altitude of 53°, in a direction S. 28° W.

The time of flight for the different observers, determined as above stated, ranged from 10 to 20 seconds-giving an average of fourteen or fifteen seconds, which agrees with the careful estimate made at the time by the observers at Prof. Porter's.

Valuable observations have also been received from individuals in different places, some items of which we proceed to state. They will be given more fully hereafter.

Mr. J. D. Lawson, of New York, saw the meteor from the corner of Fourth street and Broadway, and has furnished data which gives for maximum altitude (N.) 5610. Another independant observation at the same spot, as published in the Journul of Commerce, gives from data subsequently obtained by Prof. H. A. Newton, an altitude of about 55°. We use for N. Y. 56° as the mean of the two.

Mr. F. Huidekoper, of Meadville, Pa., makes the altitude at that place 39° 30′ from the northern horizon; the point of disappearrance at altitude 3° 30′, and 10° 45′ S. of east; time from crossing meridian till disappearance, 10 to 12 seconds.

Mr. W. King, a surveyor, at Erie, Pa., makes the altitude 44°, and point of disappearance in a cloud due east at an altitude of 220.

Mr. S. B. McMillan, of E. Fairfield, Ohio, reports it as having been seen, "moving from a point about 10° E. of N. to within as much of a due east direction," attaining an altitude of 15°.

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Rev. T. K. Beecher at Elmira, N. Y., saw it pass very nearly through his zenith, and "so very close to" Lyra "as to quench, if not eclipse it." This star was then about 11° from his zenith and in azimuth S. 761° E. The meteor separated into two parts with an explosion when near the zenith.

Other observations (not now at hand), which bave been used in obtaining our results, have been received from Mr. B. V. Marsh of Philadelphia, and Prof. Hallowel, of Alexandria.

A comparison of these observations, and a few of the best that have been published, give approximate results as follows:

(1.) The vertical plane in which the meteor moved cuts the earth's surface in a line crossing the northern part of Lake Michigan, passing through, or very near to, Goderich on Lake Huron (C. W.), Buffalo, Elmira and Sing Sing, N. Y., Greenwich, Con., and in the same direction across Long Island into the Atlantic.

(2.) In this plane the path that best satisfies the observations is sensibly a straight line approaching nearest to the earth (41 miles) at a point about south of Rhode Island, and having an ele vation of 42 miles above Long Island Sound, of 44 over the Hudson, 51 at Elmira, 62 at Buffalo, 85 over Lake Huron, and 120 over Lake Michigan. The western observations, however, which are few and imperfect, seem to indicate a somewhat greater elevation than this for the western part of the path. Possibly, therefore its true form may have been a curve convex towards the earth, resulting from the increasing resistance of the atmosphere as the meteor descended into denser portions of it. The observations made on this side of Buffalo, which are somewhat numerous and many of them good, are very well satisfied by the straight path already described. Further and more accurate observations beyond Buffalo are greatly needed for determining the true form and po

sition of the orbit, both in respect to the earth's surface and in space.

(3.) The close approximation to parallelism to the earth's surface of the eastern portion of the observed path leaves it a matter of doubt, considering the imperfection of the observations, whether the meteor finally passed out of the atmosphere and went on its way in a disturbed orbit, or descended gradually into the Atlantic. The former supposition is perhaps the more probable, especially if the path was curved, as above suggested, instead of a straight line.

(4.) The meteor exhibited different appearances in different parts of its course. It seems to have been observed first as a single body, more or less elongated, gradually increasing in brilliancy, throwing off occasionally sparks and flakes of light, until it reached the neighbourhood of Elmira, N. Y. Here something like an explosion occurred, and the meteor separated into two principal portions with many subordinate fragments all continuing on their course in a line behind each other, and still scattering luminous sparks along their track, until a point was reached about south of Nantucket, when a second considerable explosion took place, and afterwards the principal fragments passed on till lost to view in the distance. The most trustworthy observations represent the meteor as disappearing while yet several degrees above the horizon, (generally from 3° to 6° or 8°). Besides the actual changes of form which the body successively underwent, apparent changes would present themselves to each observer arising from change of direction in which the meteor was seen.

(5.) It is not easy, from the observations in hand, to determine with much accuracy the volocity of the meteor while passing through our atmosphere. The time of flight is doubtless largely over-estimated by most observers, especially those unaccustomed to measure intervals of a few seconds. Timing with a watch, a repetition of the acts performed during the flight of the meteor usually reduces the interval to not more than one third, or even one fifth, of the observer's own estimate. From 15 to 30 seconds probably to no observer.

is a fair range for good observations, and was the meteor in sight over 45 seconds or a minute, although a minute and a half and two minutes are very common estimates A comparison of the most probable estimatee of time with the length of path observed, gives a velocity ranging from eight to fifteen miles a second. Probably 12 or 13 miles is a tolerable

approximation. This, allowing for the earth's motion in its orbit, gives 26 or 27 miles a second as the actual velocity of the meteor in space. Its relative velocity may have been much greater when just entering the atmosphere, than after encountering its accumulated resistance.

(6.) The actual diameter of the luminous mass, taking its apparent diameter as nearly equal to that of the moon, (the estimate of many observers nearest its track) must have been from one fifth to one-third of a mile. Many estimates would make it still larger. The two principel heads when passing New Haven must have been from one to three miles apart.

(7.) A report is mentioned by many observers as having been heard from one and a half to five minutes after the meteor passed. The least time in which such a report could have been heard, taking the usual constant for the volocity of sound (1090-47 feet a second) would be about three minutes and a half. This is a point of much interest, and needs to be investigated.

The "rushing sound" spoken of by many as heard while the meteor was passing, is of course to be attributed to imagination.

ARTICLE XLVIII.-La Verrier's Report on the Solar Eclipse of July, 18, 1860, at Tarazona. From Silliman's Journal, September, 1860.

At the last moment, and after our notices of this phenomenon were printed (see pp. 281, 285, 288) we have received LeVerrier's Report of the Observations of the French Expedition to Spain, made to the Minister of Public Instruction, which we hasten to lay before our readers, slightly condensed, although other matters which some of our correspondents will naturally look for here are thereby displaced. The interest with which Le Verrier's new views of the physical constitution of the Sun will be read is our apology to all such.

Le Verrier was accompanied to Spain by Messrs. Yvon Villarceau, and Chacornac, who were occupied chiefly with determining the height and position of two or more of the luminous appendages. M. Foucault studied the corona, and made the photometric and photographic experiments. M. Le Verrier observed the astronomical phases of the phenomenon, and was also charged with the duty of obtaining an exact description of the whole

scene.

Two telescopes on Foucault's plan were devoted to the

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