It is of B. & M.

87. The low central range in Rhæticus, the south part. 88. The mountain-range on which IV A7 is opened. The dotted lines in areas IV A* and IV A' indicate the west foot of this mountain-range, the east requires to be determined.

IV A-103. A craterlet east of IV A 113; estimated 2-0, mag. 0-12. Not in Lohrmann, but shown by B. & M.

104. A mountain on the plain IV A 24 shown very plainly by Lohrmann on Sec. I., and mentioned in his text (p. 55) as lying in 0° 30′ of west long. and 5° 40' of south lat., direction north to south, estimated length 6" 33, breadth 3". It is inserted from Lohrmann's sections, but does not appear on the photograph. 1864, July 24, I saw and sketched it. The instrument used was the Hartwell Equatoreal, power 118, the eyepiece being furnished with a diaphragm having a narrow slit, along which the object was allowed to pass, or kept in position by the clock motion.

105. A hill between the south end of IV A 104 and IV A 47; estimated diameter 1" 75.

106. A hill between the north end of IV A 104 and IV A3 47; estimated diameter 1"-75.

These two hills which are not seen on the photograph, are from Lohrmann. They are on his Sec. I., and mentioned in his text, p. 55. I saw and sketched them 1864, July 24.

107. A slight elevation in and rather west of the centre of IV A?1, seen with the Royal Society's achromatic, 44-inch aperture, power 230, 1867, March 15, 7h 40m, G. M. T.

108. A bright spot on the north part of the mountain IV A361.

109. A bright spot on the north part of the mountain IV A'37. Both spots were seen 1867, March 15, 7o 45TM, G. M. T., with the Royal Society's achromatic, 44-inch aperture, power 230.

110. A mountain between IV A 37 and IV A 47 in the east border of Hipparchus.

111. The south part of the mountain-range IV A 88.

a

112. A craterlet near the south end of IV A 88, IV A111; estimated 3" 5, mag. 0.21. Shown by Lohrmann, but not by B. & M.

113. A craterlet S.E. of IV A112; estimated 2"-0, mag. 0·12. Not in Lohrmann, but shown by B. & M.

114. A depression N.E. of the north end of IV A110; estimated length S.W.-N.E. 4"-0. Neither in B. & M., nor in Lohrmann.

IV A 103 and IV A 110 to IV A 114, excepting IV A 111, were first seen by the author, 1867, April 11, with the Royal Society's 4-inch aperture, power 230. The positions are confirmed by the photograph, although the objects are not sufficiently distinct in the photograph to be recognized independently of observation with the telescope.

LINES OF UPHEAVAL AND DEPRESSION.

The south border of IV A 58 is in the prolongation of the line of upheaval IV A, W.N.W.-E.S.E. No. 6.

IV A S.S.W.-N.N.E. No. 5.-IV A 48 and IV A47 are in continuation of this line, which forms a gentle curve convex to E.S.E.

IV A N.N.W.-S.S.E. No. 5.-This well-marked "line of fault" from Tycho is continued across the area IV A" west of IV A 10 and Rhæticus.

The careful study of the lines of upheaval and depression is particularly recommended to lunar observers as full of promise. It is not at all unlikely that several of the "Rays from Tycho" will be found to possess the character of lines of volcanic energy. It is an interesting fact that the two points of upburst, IV A 36 and IV A32, on the "ray from Tycho" crossing the area IV A occur in localities where several lines of upheaval and depression intersect each other.

Concluding Remarks.

We would again call attention to the Note on p. 239, to the effect that the present Map is not intended to be perfect or complete; and we are the more anxious on this point, as various suggestions have been offered with the view of rendering it more efficient, with which we most cordially agree. At present the engraved portions of the Map are in outline, and will doubtless require considerable modification, as observers work at the subzones (see pp. 241, 242) which they may select. One suggestion, and a very important one, is, "that as the craters on the moon's surface are the leading objects, catching the eye first, and giving points of reference to the region under observation, it would greatly facilitate the work of observers if the craters were rendered more conspicuous in the engravings." The present imperfection of our knowledge of "detail" interferes materially with adopting any conventional mode of distinguishing one class of objects from another, further than as explained on p. 240; but as the Maps are intended for working-purposes, and are printed on paper that will bear colouring, we would strongly recommend that each observer should, before commencing his observations, tint with a suitable colour the craters in his pair of subzones; and if a few other conspicuous objects, as mountains, were desirable as points of reference, they might be tinted, but with a colour as much in contrast as possible. The portion of Beer and Mädler's map, referred to on p. 241, does not accompany this Report.

APPENDIX IV.

Determination of the apparent Equator on De La Rue's Photograph, 1865, October 4d 9h 0m 4s.

The values of the coordinates are expressed in parts of the moon's semidiameter, which is equal to unity. See Report, 1865, p. 295.

Report of the Rainfall Committee, consisting of J. GLAISHER, F.R.S., Lord WROTTESLEY, F.R.S., Prof. PHILLIPS, F.R.S., Prof. TYNDALL, F.R.S., Dr. LEE, F.R.S., J. F. BATEMAN, F.R.S., R. W. MYLNE, F.R.S., CHARLES BROOKE, F.R.S., and G. J. SYMONS, Secretary. Ir is satisfactory to state that in all branches of rainfall investigations steady progress has been maintained, and order, regularity, and accuracy more fully established than at any previous time. Mr. Symons's last Report to this Association in the volume just published, contained an epitomized history of rainfall investigations from 1677 to 1865, the present one deals principally with the progress made since the Meeting at Birmingham. The Rainfall Committee appointed at that Meeting having been fully impressed with the paramount importance of promptly collecting all the old rain records that are in any way accessible, directed that a circular should be sent to every newspaper in the United Kingdom; and as the circulars had to be modified for each journal, and there are upwards of 1400 newspapers regularly published, the preparation of these circulars was rather a tedious process, even to one pretty well used to voluminous work. They were, however, all ready at last, and posted simultaneously. It speaks volumes for the willingness of the press to help science, and for its disinterested public spirit, that these circulars (and troublesome ones to print too) were inserted by many hundred journals without a scruple or a word as to payment. The circulars were as follows::

To the Editor of the

BRITISH RAINFALL.

SIR,-I have to ask your readers' attention for a few moments to a request on the above subject, the importance of which in relation to engineering and drainage questions is well known. It is now some years since I began collecting returns of the fall of rain-with what success I will mention presently, but my main difficulty has been to find out the persons who keep such records, and one of the most obvious sources of assistance is the Public Press; I now, therefore, ask from each and every journal in the British Isles their all-powerful aid. When the collection was first organized in 1860, scarcely 200 persons were known to observe and record the rainfall; by steady per

severance, and the aid of a portion of the press, the number has been raised until there are now more than 1200 places whence returns are regularly received. Still I know there are many more, probably hundreds, who have either never heard of the establishment of a central depôt to which copies of all rain records should be sent, or they have been too diffident to send them. It is of paramount importance to gather these, and make the Tables yet more complete. I therefore beg leave through your columns to ask every reader to think for a moment if he or she knows of any one who keeps, or has kept, a rain-gauge; or who has any tables of rainfall (or old weather journals) in their possession. And if they do know of such persons, I ask them on behalf of science, of my fellow-observers, and on my own behalf, to use every effort to secure their assistance, and to favour me with their names and addresses. We want old records, we want records for the present year, and from many parts of the country we want returns for the future, if a few persons will notify to me their willingness to assist, and to pay 10s. 6d. for the very cheap and simple gauge now supplied.

To prevent needless correspondence, I annex a list of the places in Bedfordshire whence returns have been already collected for the years mentioned in the last column, and shall be very glad of any additions or corrections. Other counties, or the complete list for the whole country, shall be sent to any one willing to make good use of it. I may add that an influential committee of the British Association has been appointed to superintend and assist in my investigations, and that they cordially support my present application. I am, Sir, your obedient Servant, 136 Camden Road, London, N.W. G. J. SYMONS. The Committee consists of J. Glaisher, Esq., F.R.S.; Lord Wrottesley, F.R.S.; Prof. Phillips, F.R.S.; Prof. Tyndall, F.R.S.; Dr. Lee, F.R.S.; J. F. Bateman, Esq., F.R.S.; R. W. Mylne, Esq., F.R.S., and myself.

The practical results of the publication of upwards of a million copies of this circular were awaited with much interest. Many hundreds (if not thousands) of letters were received, but the majority of them referred either to observers with whom Mr. Symons was already in correspondence, or to old observations already collected. About 200 letters notified that the writers had recently procured rain-gauges, and would be happy to send the results in future; and about 100 only contained what was (and is) most required, namely, old observations not previously collected-some of these were very valuable records; but on the whole the result of the appeal was to confirm the belief that there are not now very many records in private hands of which copies are not already obtained and classified.

Taking, as we may, the total number of additional stations at 300, it does not seem expedient to give yet a list of them, but rather subsequently to issue a supplement to the list in the last Report, or perhaps a completed reprint.

Extraction and Classification of published Records.-We regret to say that absolutely nothing has been done in searching the Library of the British Museum during the past year. Records once there being safe, it has been judged more expedient to secure those from other quarters, where their safe custody is always uncertain; the observers die, and the records are too often destroyed. Examination of Rain-gauges.-Ever since Mr. Symons's rainfall investigations were commenced, he has made it a principal aim to visit as many as possible of the gauges actually at work, and by conversation with the observers, and by examination of the accuracy of their gauges and the suitability of their position, to secure at once stronger personal interest in the work, and greater uniformity and accuracy in the mode of carrying it on. It is therefore with much pleasure that the details of 166 such visits are annexed to this Report, drawn up, it is hoped, in such a manner as to afford a good general idea of the position of the gauges, and absolute knowledge of the degree of accuracy of each gauge at different points of its scale. Without entering at present on a minute analysis of the results of these examinations, it may be affirmed that they are on the whole immensely beneficial. As a rule, the gauges are found to be in error less than two per cent.; and though now and then he comes upon gauges which are a disgrace to those who made them, these cases are altogether exceptional. A more frequent source of error is the proximity of trees and tall plants; it cannot be too strongly impressed on observers, that they must keep a clear open space round their gauges.

Inclined and Tipping Funnelled Gauges.-At the last Meeting of this Association it was suggested by Mr. Varley and Prof. Phillips that we should ascertain the indications of a gauge whose mouth instead of being horizontal should be inclined, and kept face to wind by a vane. We are happy to be able to announce that Mr. Chrimes of Rotherham has erected, and regularly observed, a most exhaustive set of instruments for the investigation of this question. They are erected on a piece of exposed high land in the suburbs of Rotherham, and the gauges are read daily and 5 monthly.

The instruments are

1. A gauge similar to one employed many years ago by Prof. Phillips, having one horizontal and four vertical funnels, facing E., W., N., and S. Of course if the rain is absolutely vertical it will only enter the horizontal funnel; if coming absolutely horizontal, and from, say, due east, it will only enter the funnel facing east; if at any intermediate angle, it will partly fall into two or three funnels, each being provided with separate pipes and taps; the quantity caught by each is known, and the angle and point whence the rain fell can be easily calculated.

2 to 5. Four gauges revolving by vanes, and having their funnels tilted towards the wind at angles of 221°, 45°, 6710, and 90°.

6. A gauge similar to the above, except that the tilt of the gauge is not fixed, but, being supplied with levers, &c., varies with the pressure of the wind. In a dead calm the funnel is horizontal, and in a gale it will, it is hoped, be tilted to an angle of 70° or 80°. It should thus be always at right angles to the wind, and catch more than any other gauge in windy weather.

7. A Robinson's anemometer, to give the horizontal motion of the air. 8. A set of gauges at different elevations-10 feet, 15 feet, 20 feet, and 25 feet above the ground; two at each height, one for daily and one for monthly measurements. These, and also the above-mentioned gauges, are all 5 inches diameter.