This morning he had noticed an appearance of which he made a sketch on the blackboard. He did not say it was a solar corona, but it did not arise from the eye-piece or the coloured screens. Dr. Huggins had suggested it might be due to the eye of the observer.

Dr. Huggins mentioned that a friend of his had looked for these appearances in vain.

Capt. Noble said that some years ago* he observed the dark limb of the moon projected on the sky during a partial eclipse, and, upon stating it to the society, was asked by the Chairman (Professor Pritchard) whether he was using a coloured glass, and upon his replying yes, was told that "accounted for anything," but perhaps after all his observation was not so worthless as had been supposed.

Mr. Chambers said he had seen the phenomena in question. Lord Lindsay did not think it could be the corona that was seen, as a dark glass was used, and the corona as seen in eclipses could not possibly be seen through a dark glass.

Colonel Tennant agreed in this, and said he had looked for the projection of the moon's limb on the sky at the last eclipse, and was certain that it was not visible. It may have been seen sometimes, but was not then.

On future Solar Eclipses: by Rev. J. S. Johnson.
On Eclipse Photography: by Mr. Brothers.

Comparison of the Photographic Pictures of the Corona taken in 1869-70-71 by Mr. Ranyard.

:

Observations of Jupiter in 1871-72 by Mr. Browning.

This paper was illustrated by four beautiful coloured drawings of the planet, and the author explained that his attention had been concentrated on obtaining the most striking examples of the colouring of Jupiter, and that the details of configuration had therefore, received less attention, the nights chosen being those when coloration was strongest.

It was announced that two of the drawings would be reproduced in chromo-lithograph for the Monthly Notices. The meeting then adjourned till November.

Errata in last report.

The occultations observed by Capt. Noble (p. 134) took place on April 18th, 1872. In line five for Ioh. read 11h. Page 140, line 31, for formal read journal.

* March 6, 1867, Astronomical Register, Vol. V., p. 83.

169

CORRESPONDENCE.

N.B.-We do not hold ourselves answerable for any opinions expressed by our correspondents.

TO THE EDITOR OF THE ASTRONOMICAL REGISTER. PLANISPHERE OF JUPITER, APRIL, 1872.

;

Sir,-The planet Jupiter is passing from our view, and exact observations of its belts must be deferred until it has passed its superior conjunction. Considerable changes, both in the disposition and colour of the belts, have occurred during the last three years. These changes have attracted much attention, and formed the subject of several interesting letters in the Register. Having observed the planet somewhat closely through the past twelve years, during which time it has been my habit to obtain a drawing on every available occasion, I trust that a rough sketch of the general arrangement of the belts, as exhibited in these studies, may be acceptable to some of your readers. Observations were commenced in the spring of 1859; at that time the planet was passing from opposition, and whether from great faintness in the markings of the belts, or inexperience in the observer, no lines on its surface could be perceived. In the fall of that year several studies were made in the early morning, when the belts were clearly visible, showing a great development of the southern dark belt, the northern being comparatively weak the centre of the disc was then occupied by a band of light. From 1860 to 1863 there was a general tendency in the southern dark belt to increase in size and activity; while the northern, though it generally increased after opposition, continued the smaller, and was less given to change. The central band of light exhibited frequent spots, and was also some what reduced in breadth. From this period to 1867 the southern belt gradually lost its size and tendency to alteration in form, whereas the northern became more evident and active. In September of this year the northern belt was very dark, and brownish in colour, while the southern, though broader, was faint and gray; the centre of the planet being occupied by a brilliant white band. In 1868 the southern dark belt resumed its activity, exhibiting frequent spots of a darker tone, and the centre of the planet retained its white appearance. But between the end of this year and the opposition of 1869 great changes had taken place; the central light had disappeared, its place being occupied by a broad band of a yellowish copper colour, and the whitish portion of the disc was then, for the first time during these observations, on the north side of the northern dark belt. In October of 1869, colour took a very prominent part in the appearance of the disc, the southern belt being

gray, while the northern was decidedly blue, and the whole surface of the planet seemed streaky from the number of small belts, which extended nearly to the poles. From this important period to the present time the general appearance has not greatly changed; the intensity of the copper colour has somewhat disappeared, and there has been considerable activity in the smaller belts and markings, especially towards the south; also a decided tendency to permanence and increase in the dark norther n streak, No. 2. A glance at the lithograph will present these changes more readily to the eye than a page of description: there the tendency of the southern dark belt to maintain its preponderance till 1868 will be clearly seen, as also the strength of the central band of light in 1866-7, and its change to the copper tone in 1869.

An endeavour is made in the two larger drawings of the plate to represent the general features of the planet in April last, and as the second of these views was procured on the following evening, and at about the same hour, the two drawings present very nearly opposite portions of the planet's surface. It must not be understood that these drawings exhibit all that could be seen, but all that could be fairly drawn. In moments of steadiness of the atmosphere a minute mottling of the surface was perceptible, and the belts appeared fringed with smaller markings. But these glimpses were most tantalising, being utterly beyond the power of the eye to seize, or of the hand to follow. Few indeed have been the evenings since February last, when a choice 9-inch With-Browning Reflector was mounted, that a higher power than 200 could be used with advantage. However, during the last three months over forty drawings have been secured, and a short account of the method of arranging them for comparison may not be out of place.

When a definite mark has reappeared on several occasions, the drawing in which it is most central is chosen as a starting point, and the disc divided by a simple perspective diagram into five equal parts, the central division being called the first hour. A calculation is then made for each drawing, allowing 595 minutes to a revolution, and the time of each registered underneath the drawing. By this means the equator of the planet is divided into ten portions, each division answering fairly to an hour of revolution; thus one drawing can be readily compared with another, and changes become more evident, being presented to the mind in this simple but effective manner. When a sufficient number of drawings has been made, they are combined in the form of a planisphere, an example of which is given in the woodcut at the head of this letter, in which the fourth and eighth hours form the centres of the two drawings. This method of study has been found very interesting and instructive, as it exhibits, in the most conclusive manner, the bearing of the markings in one drawing with those of another, and occasionally develops the most unexpected connections. The whole surface is also presented at one view, and thus the peculiar features of any portion are made more impressive. The numbers at the side of the woodcut are adopted from Mr. Jos. Gledhill's arrangement, and are most convenient when referring to any particular belt. Hoping that your readers will not be offended at the length of this letter, but that it will be received as a humble effort to promote a systematic study of this King of the planetary world.

3, Circus Road, St. John's Wood, London: May 20, 1872.

I remain,

ASTRO-METEOROLOGY.

Sir,-"Observer" is only treating us again to a few platitudes on the subject of the weather.

Of what conceivable scientific value, I would ask, can we consider a system, or theory, to be which connects the opposition of a planet with a barometric depression occurring 4 days afterwards? Why, if we are to admit this, and say that the effect of such opposition may be visible 4 days before, or after it occurs, this gives us 9 days altogether, or about a third of a month, during which we may look for a coincidence of some sort. Besides, before rushing into print, has “Observer" examined his former meteorological registers ? because I fancy that I have somewhere heard or read that both Jupiter and Uranus have been in" opposition" before last January.

Nothing is more fallacious than a deduction drawn from insufficient data. To render " Observer's" hypothesis worth a rush, a long sequence of planetary" aspects" should be compared (fairly, not in 9 day periods) with the recorded barometric pressure at Greenwich. A few extremely doubtful coincidences prove nothing. Did your correspondent never hear of the appearance of the Goodwin Sands in the North Sea, contemporaneously with the building of Tenterden Steeple ? I am, Sir, obediently yours,

June 7, 1872.

ANOTHER OBSERVER.

CONNECTION OF METEOROLOGY AND ASTRONOMY.

Dear Sir, I have read with great interest, in your report of the Meeting of the Royal Astronomical Society, April 12, 1872, Col. Strange's paper; and the discussion which followed cannot but draw attention to the fact that Meteorology and Astronomy are closely connected, and that by the joint study of those sciences we may arrive at the practical results alluded to by the Astronomer Royal.

Since the publication of the " Edinburgh Temperature Record," by C. Piazzi Smyth, Astronomer Royal for Scotland; and the results arrived at, at the Cape of Good Hope, by Mr. Stone; together with the coincidence between the condition of the sun's surface and Toronto Rainfall, which has been clearly established; it seems to me impossible to avoid the conclusion that there is some direct or indirect connection between the sun spots and weather changes.

It may be of importance that additional observatories should be brought into existence to prosecute this work (and I regret the discontinuance of the Kew observations: three or four sun spot periods are needed to settle some important questions), but it is possible that materials exist already, which, if properly used, may help to show still further that important practical results may follow the establishment of such an observatory as Col. Strange contemplates.

But though such a work may not be carried into effect, something may be gained if your readers will send to the Register the annual means of any observations to which they have access.

For instance: the Table which you published in the Register of Nov., 1871, in the letter of W. Lawton, Esq., of Hull, teaches a lesson which, perhaps, he has not noticed himself.

Let the numbers of clear nights given in that table be thrown into a curve, and it will be seen that our Yorkshire friends have had a very

cloudy period at the maxima and minima of sun spots; and fine, clear weather between maximum and minimum. That table does not give the number of cloudy nights for 1871, the year of sun spot max. (or possibly the one immediately following). I doubt not, if he will now supplement that table, we shall find 1871 a cloudy year.

I will, with your permission, call attention to a few additional facts in this and a following letter, and hope your readers will furnish others.

Since the year 1854 a record has been kept by the Toronto Harbour Master of the height of the water in Lake Ontario, and as this lake is fed by rivers extending over a large territory, it gives an excellent method of estimating the general precipitation during that period.

The figures show in inches of annual mean height above a zero, which is an arbitrary mark, on a scale used for the purpose of measuring the water height.

TABLE IV.-ANNUAL MEAN HEIGHT OF WATER ON LAKE ONTARIO.

By making a curve of these numbers we find that the state of our Lake's waters has been low about the time of sun-spot maxima and minima. Truly yours,

A. ELVINS.

MERCURY.

Dear Sir,-By the appendix to the Register for the present month, I see the Rev. S. J. Johnson observed the planet Mercury on the evenings of the 25th March and 5th April.

Having a good aspect westward, my residence being situated on the extreme western limits of the town, I carefully searched for the planet on every opportunity during its last eastern elongation, but only on the evening of the 26th March, at 7:30, was I able to obtain a brief glimpse of this rarely seen member of our system, and this only through vapours which seriously interfered with the definition of an excellent 2-inch refractor by Thos. Cooke and Sons, equatorially mounted.

By far the most satisfactory view I ever had of this planet was about 6.15 on the evening of the 15th February, 1868, one of the clearest I ever remember. On that occasion, with powers from 50 up to 100 on the above instrument, I was able to observe the gibbous aspect of the planet, and also took note of its brilliancy. Part of the entry in my notebook is as follows: "With a power of about 50 the gibbous aspect of the planet is visible, and its disc very bright." On the following and succeeding evenings I was again on the look-out; but only on the 16th, from 6 to 6.15, was I able to get even a transitory sight through openings in