50 



ASTRONOMICAL PROGRESS IN 1898. 



systematic conduct of the photographic work of geo- 

 logical surveys; (3) the appointment of a seismo- 

 logical committee for the year 1900; (4) the ap- 

 pointment of a committee to secure magnetic 

 surveys at the extreme southern portion of New 

 Zealand ; (5) that the committee be reappointed to 

 continue the investigation of the mineral waters of 

 'Australia; (6) that the New South Wales Govern- 

 ment !>< recommended to complete the borings at 

 Funafuti, while the boring apparatus remains at the 

 island and the bore remains open; (7) that a com- 

 mittee be appointed to draw up a list of works and 

 papers relating to Australian flora; (8) that the 

 Government of New Zealand equip Timaru with 

 approved seismological instruments, to be placed 

 in charge of Mr. George Hogben, and that a con- 

 tribution of 25 be granted toward carrying out 

 that object. All of which were adopted. The 

 usual votes of thanks were passed, and the sessions 

 declared adjourned. More than 300 members were 

 present at the meetings, and 269 papers were pre- 

 sented. 



Next Meeting 1 . The meetings of the association 

 are naturally held in the different colonies in succes- 

 sion, and in order that ample time may be had for 

 preparation the place of meeting is usually desig- 

 nated at least two meetings in advance of the gath- 

 ering. In 1900 the meeting will be held in Mel- 

 bourne. Victoria, and in 1902, by rights, the 

 meeting should be held in New Zealand, but as the 

 representatives of that colony asked for postpone- 

 ment, Tasmania was selected and the place named 

 was Hobart. For the presidency of the Melbourne 

 meeting R. L. J. Ellery, late Government astrono- 

 mer of Victoria, was chosen. C. R. Brackett, Gov- 

 ernment analyst of Victoria, was elected local 

 treasurer, and W. Baldwin Spencer and E. F. J. 

 Love, local secretaries. 



ASTRONOMICAL PROGRESS IN 1898. As 

 regards important discoveries in astronomy, the 

 present year may be said to equal any of its pred- 

 ecessors since the discovery of the fifth satellite of 

 Jupiter. 



The Sun. Although since the invention of the 

 telescope the Sun has been subjected to most rigid 

 observation, yet in regard to his physical structure 

 the cause of his light, and heat, and spots, and 

 faculae, and pores, and prominences, and coronal 

 atmosphere, or whether he contains any solid 

 matter at all we know absolutely nothing. There 

 is not an astronomical fact on which to base the 

 oft-repeated theory, that eighteen million years 

 hence he will cease his shining and become a worn- 

 out world. Neither is there an astronomical fact to 

 prove that his heat was ever less intense than in 

 our age. 



To obtain the Sun's horizontal parallax has always 

 been considered the grandest problem that man 

 ever attempted to solve. Though its true value 

 ha- doulitle IH-CU obtained within narrow limits of 

 error, yet it is not certain that its exact value has 

 been ascertained. It is now assumed to be 8.80", 

 the mean of its determinations by various processes, 

 including the transits of Venus. Adding to or 

 subtracting from this value the minute amount of 

 only 0.01 " decreases or increases the computation of 

 the Sun's distance from the Earth to the extent of 

 105.000 miles. 



The following statistics regarding the Sun, 

 though probably not exact, are the. most reliable 

 that can be given now. They are based on the 

 assumption that his (parallax 'is 8.80': His mean 

 distance from the Karth (always reckoned from 

 center to center) is 92,885.000 miles, with a varia- 

 tion between Jan. 1 and Julv 3 of 3.100,000 miles, 

 owing to the ellipticity of the Earth's orbit. His 

 angular diameter = 32' 4", and his linear diameter 



886.400 miles, or 109.3 times that of the Earth. The 

 mean time of his rotation on his axis is about 

 25.38 days, but in different latitudes the time of 

 rotation differs, being twenty-five days at Iris 

 equator, and increasing to 27.5 at latitude 45 north 

 or south. Authorities differ widely as to the 

 temperature of his surface. The lowest estimate 

 (probably much too low) is 18,000 F. or 10,000 C. 

 Until the Sun's parallax is exactly ascertained it is 

 incorrect to say that planets are so many miles 

 fro'rn the Sun ; it should be said they are so many 

 times the Earth's distance. When this was assumed 

 to be 95,000,000 miles, the computed distance and 

 volume of every heavenly body (the Moon ex- 

 cepted) was too great. 



At the eclipse of the Sun on Jan. 21, 1898, 

 which was total through India, and was observed 

 by a large number of astronomers, many important 

 observations and discoveries were made, as at every 

 station occupied by astronomers the sky was clear. 

 At this writing only brief newspaper reports have 

 been published, the more extended ones being 

 reserved for publication in " An Eclipse Volume." 

 The great southwest ray which attracted so much 

 attention, as photographed by Mrs. Maunder, 

 extended to six diameters of the Sun, or a distance 

 of 5,188,400 miles. This is the longest coronal 

 streamer ever photographed, though Prof. Langley 

 claims to have seen one from Pike's Peak at the 

 eclipse of 1878 extending to a distance of nearly 

 10,000,000 miles. 



The corona is a magnificent appendage or halo 

 surrounding the Sun, whose diameter is at least 

 10,000,000 miles, seen only during the few moments 

 of total eclipse. Near the Sun it appears like 

 striated filaments, some radial and others tan- 

 gential, its circumferential portion ending in a 

 diffused light. While the prominences are red, the 

 corona is of silver whiteness. Recent s'pectroscopic 

 analysis of the coronal light gives a faint continu- 

 ous spectrum, showing it to be from solid matter ; 

 also an additional spectrum of bright lines ema- 

 nating from glowing gases, notably from hydrogen. 

 In the green there is a double line, which fora long 

 time was without a known representative on the 

 Earth, and was called the 1474 line before it was 

 found to be double. Finally it received the name 

 helium. This is now found to be a widely dis- 

 tributed terrestrial element, though in very 

 minute quantities. One of the lines is now found 

 to coincide 'with a dark iron line in the solar 

 spectrum. The substance producing the other line 

 has not been found on the Earth. It has received 

 the name coronium. 



Mercury. Astronomers are not in accord on the 

 subject of the alleged markings on Mercury. The 

 weight of evidence, which, of course, is purely 

 negative, is against their reality. Whether, there- 

 fore, he rotates in about twenty-four hours, as 

 many suppose, or in eighty-eight days, is still a dis- 

 puted point, as is also the question whether the real 

 surface of the planet ever has been seen. 



Venus. The remarks above apply also to Venus. 

 a world that, with the exception of the Moon and 

 the newly discovered asteroid DQ, makes the near- 

 est approach to the Earth of any heavenly body. 

 Some astronomers with inferior instruments, usini; 

 small apertures, claim to see markings of dark 

 streaks similar to those that some see on the planet 

 Mars. On the other hand, astronomers of large 

 observational experience on planetary details, and 

 with telescopes of mammoth size, like those at the 

 Lick and Yerkes Observatories, see nothing at all. 

 We are confronted here with one of the strangest; 

 and most inexplicable phenomena within the do- 

 main of observational astronomy. The drawings 

 of those who claim to see the markings do not agree 



