photograph of the totality. In preparing this illustration the lithographer has been very successful in copying my sketch, the plate as given recalling the protuberance to my mind with great freshness and power. The flaky structure of the protuberance I have endeavoured to indicate by a deeper tint of orange running diagonally across the flame. The southern end is more compact than that turned towards the equator, which latter breaks up into several smaller independent clouds, between which, and suspended fully 10,000 miles above the solar surface, projects the tapering point of the "anvil." A casual glance at the sketch impresses one with the idea of a down-rush of the glowing matter from the southern end to the "anvil" point.

The details of the termination of this tapering end are wholly from my notes, which record that this part of the protuberance was composed of "fibrous lines of flame" apparently in motion and emitting a tremulous light. I have now a vivid recollection of the impressions produced upon my mind by this portion of the phenomenon which riveted my attention for some moments. In the photographs the tapering end of the protuberance terminates in a misty ball, which is what we should expect if the fine lines revealed by the telescope were really in motion.

One word regarding the corona. By a slight movement of my instrument its limits were brought into view, and its extent quickly indicated on diagrams previously prepared. At the same time I indicated by two heavy pencil-marks the positions of certain bands, or intervals, in the light of the corona on opposite sides of the moon's disc. These dark intervals deserve a passing notice.

In my coloured sketch of the corona, made immediately after the eclipse, and which accompanies my report published by the Washington Naval Observatory, I have indicated the positions and character of these bands. The absorption bands of the solar spectrum occurred to me at the time as an illustration of the delicate striations in these portions of the corona. In the case of one gap a multitude of fine violet lines were compressed into a space of about 10° in width, forming, to my mind, one of the most beautiful features of the eclipse. The same striated appearance was noticed in other regions of the corona, though in a less striking degree.

These apparent gaps in the corona's light I judged to be opposite elevated portions of the chromosphere, from the fact that there was a similar diminution of light above the great protuberance, as my sketches show. This point was not carefully examined, however, from want of time. On my return from the south, in February last, it occurred to me to compare my sketch of the corona with the diagram of protuberances accompanying Professor Mayer's report in the October number of the Journal of the

Franklin Institute,' published in Philadelphia. This I did, for the first time, on the 9th of that month, finding a fair agreement between the southern portions of his prominences 5 and 10, and the dark bands given in my sketch. I have, therefore, little doubt but that in locating these dark intervals in my original sketches, I intended to place the western one near 285°, and the eastern one near 120°, great exactness not being obtainable in the few moments given to the observation. In speaking of these bands as dark, I would be understood only as meaning that they were sufficiently so to be readily seen.

A comparison of the Des Moines and Ottumwa pictures of the "anvil" protuberance gives the following measurements. It will be noticed that the figures are somewhat in excess of those obtained from the last totality picture made at Burlington.

Thus if, as is probable, the entire protuberance was not visible, its base being beyond the sun's limb, we have a bright cloud in the solar atmosphere nearly, if not quite, equal in volume to the planet Jupiter, and which in the direction of its length would suffice to reach more than half way to the Moon in her perigee.

THE SURVEYS OF
OF INDIA.

II. THE TRIGONOMETRICAL SURVEY.
(With a Sketch-map.)

By F. C. DANVERS, A.I.C.E.

THE surveys of India may be divided into two classes-viz. the Great Trigonometrical, and the Geological. In connection with the former, other minor operations are undertaken under the title of topographical and revenue surveys, to which we shall refer more particularly in due course.

The idea of a great trigonometrical survey of a country, to be undertaken by the Government of that country, was first conceived by General Watson, at the suppression of the rising in Scotland in 1745. The execution of it was committed to General Ray, and was originally intended to extend no farther than the disaffected districts of the Highlands. The design, however, was subsequently enlarged, and the grand trigonometrical survey of Great Britain