452 



NATURE 



{April d,, 1878 



are maintained by the constant impact of meteoric matter. 

 I never ventured an opinion as to the accuracy of this 

 theory ; that is a question which may still have to be 

 fought out. But I refer to it as an illustration of the 

 force of genius with which Mayer followed the mechanical 

 theory of heat through all its applications. Whether the 

 meteoric theory be a matter of fact or not, with him abides 

 the honour of proving to demonstration that the light and 

 heat of suns and stars may be originated and maintained 

 by the collisions of cold planetary matter." 



His services were recognised by election to membership 

 in the French Academy of Sciences and other foreign 

 societies, and two years before his death the King of 

 Wiirtemberg elevated him to the nobility. Mayer received 

 the Copley Medal of the Royal Society in 1871. 



CUR ASTRONOMICAL COLUMN 



Total Solar Eclipses.— The eclipse of the sun on 

 July 29, in whichi the belt of totality traverses the North 

 American continent from Behring's Strait to the Gulf 

 of Mexico, is a return of the eclipse of June 16, 1806, 

 which was observed in the United States by Bow- 

 ditch and the well-known Spanish astronomer, Ferrer ; 

 in this year it was central, with the sun on the 

 meridian in 65° 30' W., and 42° 23' N., and the duration 

 of total eclipse exceeded five minutes. At its next 

 return on June 27, 1824, it was total at apparent noon 

 in 170° 4' W., and 44" 42' N., but the course of the 

 central eclipse was almost entirely an ocean-track. In 

 1842, on July 8, the total phase passed over the south of 

 Europe, and was observed by a great number of astro- 

 nomers, amongst them by the Astronomer- Royal at the 

 Superga,near Turin, and byBaily,at Pavia,and Arago, who 

 was stationed at Perpignan, gave a graphic account of 

 the circumstances attending the extinction of sunlight, 

 which has been often quoted. At the ensuing return 

 of the eclipse in i860, the "Himalaya" expedition was 

 organised, and numerous descriptions of the phenomenon 

 are upon record ; one of the best of them is that given before 

 the Royal Society, as the Bakerian Lecture, by Mr. de la 

 Rue. American observers will doubtless render good 

 account of the eclipse in July next. Its last return in 

 the present century will take place on August 9, 1896, 

 when it will be total soon after sunrise in the north of 

 Sweden and Norway, central at apparent noon in 112° 21' 

 E. and 65° 38' N. between Nova Zemlia and the main- 

 land of Asia, ending in 179° 3' W. and 18° 35' N. in the 

 North Pacific. 



We have already given in this column some particulars 

 of the total phase as it will occur in the present year in 

 the United States. The last total eclipse visible in that 

 country took place on August 7, 1869, and is the subject 

 of detailed description in a very interesting appendix to the 

 Washington Observatio7is. The line of totality in the 

 eclipse of January 11, 1 880, will just reach American ground 

 before sunset ; some fifty miles south of Monterey, in Cali- 

 fornia, the eclipse will be total for about forty seconds, but 

 the sun will be at less than 2° altitude, thus affording a 

 similar case to that which some interpreters of Herodotus 

 have supposed to have occurred in the eclipse of Thales 

 at the site of the battle between the Medes and Lydians 

 when " day was suddenly turned into night ; " though of 

 course a characteristic of every total eclipse, it does not 

 frequently happen that after a long ocean track the total 

 phase is just landed on the coast of a continent at sunset. 

 But although January, 1880, will witness what is strictly 

 the next total eclipse of the sun on the soil of the United 

 States, it does not appear that there will be one favourably 

 circumstanced for observation until the year 1923, on 

 September lo. As it is possible some readers may be 

 interested in seeing the particulars of this eclipse, in con- 

 nection with the phenomenon in July next, or as the next 

 following eclipse in which totality can be well observed in 



any part of the North American continent, we give 

 elements, &c., here, derived upon a similar system of 

 calculation to what has been applied to other eclipses in 

 these columns. 



G.M.T. of conjunction in R.A. 1923, Sept. 10, at 8h. aStn. 42:. 



Right Ascension 



Moon's hourly motion in R. A. 



Sun's „ „ ,, 



Moon's declination 



Sun's ,, 



Moon's hourly motion in decl. 



Sun's ,, ,, „ 



Moon's horizontal parallax . . . 



Sun's ,, ,, 



Moon's semi-diameter 



Sun's 



58 6 55-4 



34 53-8 



2 149 



S 38 34 -o N, 



5 6 14-5 N. 



II 51 S. 



o 56 8 S. 



59 55-3 



h-8 



16 197 



15 537 



Hence the central and total eclipse commences at 

 7h. i5-6m. in long. 154° 38' E.,lat. 48° 24' N. ; it falls with 

 the sun on the meridian in 127° 54' W., and 38° 5' N., and 

 ends at loh. 157m. in 63° 25' W., and 13° 50' N. The 

 following are also points upon the line of central 

 eclipse : — 



Long. 



Lat. Zen. Dist. 



Long. 



Lat. Zen. Dist. 



Local mean times. 



120 13 W. ... 34 ON....3I-I j 106 12 W. ... 26 22 N. ...407 

 n6 52 ...3218 ...33-1 I 9433 ...2055 ...54-9 

 112 25 ...2947 ...347 I 81 14 ... 16 41 ...71-1 



Calculating directly for the first of these positions 

 which is near the N.W. point of the island of Santa 

 Cruz, off the Califomian Coast, we find 

 Totality begins at oh. 46m. 22s. 

 ,, ends at oh. 49 m. 563. 



The duration of the total eclipse on this coast will 

 therefore be about 3I minutes, with the sun at an altitude 

 of nearly 60°. 



GEOGRAPHICAL NOTES 



China. — Lieut. Gill, R.E., who, a short time back, 

 arrived in British Burmah, after succeeding in traversing 

 China from Shanghai to the Yiinnan frontier, has fur- 

 nished a Rangoon paper with an account of his journey. 

 Lieut. Gill, in the first instance, proceeded, via Hankow, 

 to Chung-king, in Szechuen, whence he made a trip to 

 the northwards, visiting the fire-wells of Tsi-liu, at which 

 place are also found brine-wells, from which good salt is 

 made. Mr. Gill made his way to Sung-pao-ting, on the 

 borders of the Koko Nor, and to Liang-ngan-foo, returning 

 by a different route to Cheng-tu. Being joined by Mr. 

 Mesney, the two began their long, perilous, and arduous 

 journey to Burmah overland, in the course of which they 

 passed Bathang, on the borders of Thibet, in about N. 

 lat. 30°. Near Bathang ranges were crossed which 

 were some 1 5,600 feet in height. The most common tree 

 near Bathang is the pine, which in some places was seen 

 in magnificent forests, and many of the trees were found 

 to be about three feet in diameter. 



A correspondent of the North China Herald, writing 

 from Chefoo, says that a scheme is under consider- 

 ation for working the coal-mines of the province of 

 Shantung, which is well known to be rich in mineral 

 wealth. Some 120 miles to the west of Chefoo there is a 

 fine level plain, under which at no great depth is a bed of 

 coal twenty feet thick. The natives have from time 

 immemorial been digging holes and getting a little out 

 here and there, but as they have no means of drainage, 

 the pits have filled with water as soon as they reached 

 the good coal. The Chinese Superintendent of Customs 

 at Chefoo, has obtained permission to form a native 

 company to carry out the work, with the aid of modern 

 appliances. The scheme referred to is understood to 

 include a tramway to the port of Chefoo. Another project 

 on a larger scale has been formed under the auspices of 



