2IO 



NATURE 



{July 6, 1876 



stoma forms, to be analogous to cases of degeneration, or return 

 to an abandoned course of development, rather than to the 

 commencement of a new stage of progress. The adaptational 

 advantages, which caused the larval form to become persistent, 

 ceasing to operate, the Ambly stoma form may very possibly, in 

 time, reobtain its reproductive powers and its position as the 

 normally perfect ammal of which the Siredon is the larva. 

 June 28 G. S. Boulger 



Remarks upon a Hailstorm which passed over Belgaum 

 on April 21, 1876 



About 1.30 p.m., after some light rain, large hail-stones com- 

 menced falling one here and there, and gradually thickening for 

 ten minutes, were followed up by a sharp shower of rain. 



The first stones which fell were of a compressed oval shape, 

 with sides slightly rounded or bulging, about I inch in length 

 and f inch in breadth, the centre being about \ inch thick. The 

 centre or nucleus of the stone was about the size of a large pea, 

 and appeared to consist of a mass of infinitesimally minute air- 

 bubbles. Surrounding this nucleus were two collateral tracings — 

 not rings, for they were far from being round — unlike in form, 

 the one occasionally bulging beyond the other : — 



Towards the end of the storm the hail-stones decreased in size 

 and assumed a rounded shape, about \ inch in diameter, with 

 the same internal conformation, but proportionately small com- 

 pared with the size of the stones. G. A. Newman 



Williams' (?) Thermometer 



As the Physical Loan Collection at South Kensington includes 

 a new (?) thermometer by Mr, John Williams — I presume the 

 son of the late Secretary of the Astronomical Society — I hereby 

 beg to vindicate my priority therein, as printed in the London 

 Philosophical Magazine for Junvmry 1850, vol. xxxvi. My com- 

 munication is dated Dec. 6, 1849, wherein I proposed making 

 the common — 40° F. or C. to be the zero, and the boiling-point 

 of water 1000 ; being 252° F. or 140° C. interval. Also putting 

 zero at — 38° F. to have 250° F, for the extreme difference. 

 This would generally avoid negat. deg. (and even the decimal 

 pointing), mere, freez. — 39 = + 4 or — 4 according to the 

 scale 252 or 250 : — 



F. o = 1587 



32*= 2857 



39 =- 313*5 



50 = 357-1 



84 = 492*1 



98 = 547-6 



152 

 280 

 308 

 352 

 488 

 544 



150 = 



174 = 

 212* = 



655 = 

 672 = 



754-0 



849*2 



1000 'O 



2758-0 



2825-4 



752 



848 



1000 



2772 



2840 



In a tract on the Limits of the Atmosphere, printed in 1840, I 

 showed that the absolute zero of cold is unattainable. Pour any 

 fluid substance in a cylinder, and mark the dilatation points for 

 32" and 212° F,, it is obvious that by carrying thS scale down- 

 wards to the bottom of the cylinder, that the fluid cannot con- 

 dense to the very bottom of the vessel, else its density would be 

 infinite. At or before this lowest degree of the scale the said 

 fluid will therefore remain stationary or begin to expand upwards, 

 as water does at 32°. I enclose copies printed at the time of my 

 said papers. S. M. Drach 



June 26 



The Cuckoo 

 There is a saying in Somersetshire : — 

 " The Cuckoo sings in April, 

 The Cuckoo sings in May ; 

 The Cuckoo sings the day before 

 But not on Midsummer- day." 

 This year, the cuckoo sang cheerily on the 24th, and is still sing- 

 ing on the 28th with undiminished vigour. H. M. Adair 

 Taunton 



Geology of Zermatt 

 Being about to spend some time in the Zermatt district, I 

 should be much obliged if any of your readers could give me 

 through your pages (as the information would doubtless be 

 serviceable to others) the titles of such works on the geology and 

 mineralogy of that portion of the Alps as they can recommend 

 from their own use of them. Viator 



OUR ASTRONOMICAL COLUMN 



The Total Solar Eclipse of 1878, July 29.-011 

 March 26 of the present year an anmilar eclipse passed 

 over British Columbia, the sun being high in the heavens 

 and near the meridian when the annulus was formed. 

 On July 29, 1878, the still more interesting phenomenon, 

 a total solar eclipse, will be visible in the same district, 

 the track of the central line passing thence over the 

 western states of America to the Gulf of Mexico. Our 

 American confreres will no doubt give a good account 

 of it. 



The duration of totality attains a maximum in British 

 Columbia, and the present remarks will be confined to 

 the passage of the total eclipse over this country. Em- 

 ploying the Nautical Almanac elements, which as regards 

 the moon's place are in very close agreement with those 

 of the American ephemeris founded on the tables of Prof. 

 Peirce, and making a direct calculation for longitude 

 123° 30' W., latitude 53° 30' N,, we find the following 

 particulars : — 



h. m. s. o 



Totality begins July 29, at i 32 24 local M.T. at 61 from N.Pt. towards W. 

 ,, ends „ ,, I 35 36 ,, „ 118 ,, „ E. 



The duration is therefore 3m. 12s. The sun's altitude at 

 the middle of the eclipse is 52°. 



A similar calculation gives for the commencement of 

 the partial eclipse oh. 19m. 47s. local M.T. at 62° from 

 the sun's north point towards the west, altitude 56°. 



For any other point not far from the above- assumed 

 position the times of beginning and ending of totality 

 may be deduced from the following formulas : — 



Cos. iu = 51-5275 - [i 846J2] sin. / + [1-67405] COS. /, cos. [L + 203° 44'-5) 

 i = 9h. 59m. 4-6s. ^ [1-98350] sin. i» — [3-56410] sin. / 



— [3 86142] COS. /, COS. (L + 245° 6'-7). 



The beginning of the partial eclipse will be given by — 



Co«. TV = 0-98476 — [0-19431] sin. / + [0-00582] COS. /, COS. (L + 184° 34''7) 

 / = loh. 19m. 43s. — [3-65657] sin. iv — [3-55998] sin. / 



— [3 88264] COS. /, cos. (Z + 227° i9'-4). 



In the above formulae L expresses the west longitude 

 from Greenwich taken negatively, I the geocentric lati- 

 tude, and the quantities within the square brackets are 

 logarithms. Upper sign for beginning of totality, lower 

 sign for ending. 



The following figures should define pretty accurately 

 the limits of the belt of totaUty in British Columbia : — 



Geographical Latitude of 



Fort Fraser, it will be seen, is very nearly on the line 

 of central eclipse. 



At a point, longitude 121° 37' W., latitude 52° 27', just 

 south of Lake Quesnelle, the central lines of the annular 

 eclipse of March, 1876, and the total eclipse of July, 

 1878, intersect. 



At New Westminster, the capital of British Columbia, 

 the eclipse is partial only, commencing at oh. 30m. and 

 ending at 2h. 59m. local mean times, magnitude 0-95. 



Bessel's " Abhandlungen."— The second volume of 

 the reprint of Bessel's astronomical and other memoirs, 

 under the editorship of Dr. Engelmann, of Leipsic, has 

 appeared. The contents relate to the theory of instru- 

 ments, including the treatises of the great Konigsberg 



