November 7, 1890.] 



SCIENCE. 



257 



that it has its lower edge suspended above the earth at a 

 height of from 50 to 100 miles ; the mean of 18 trigonometri- 

 cal measurements, taken with a base-line of 50 miles, being 

 75 miles. The aurora forms a ring round the pole, which 

 changes its latitude four times a year. At the equinoxes it 

 attains its greatest distance from its pole, and at midsummer 

 and midwinter it approaches it most closely, and it has a 

 zone of maximum intensity which is placed obliquely be- 

 tween the parallels of 60° and 70° north. The length of its 

 meridional excursion varies from year to year, decreasing 

 and increasing through tolerably regular periods, and reach- 

 ing a maximum about every eleven years, when also its ap- 

 pearance simultaneously attains to its greatest brilliancy. 

 Again, it has its regular yearly and daily movements or pe- 

 riods. At the winter solstice it reaches its maximum annual 

 intensity ; and it has its daily maximum at from 8 P.M. to 

 2 A.M., according to the latitude. Thus at Prague, in 50° 

 north latitude, the lights appear at about 8.45 p.m. ; at Up- 

 sala, 60*^ north latitude, at 9.30 p.m. ; at Bosskop, 70° north, 

 at 1.30 A M Now, while these data may be true for the 

 northern hemisphere, it remains to be proved how far they 

 apply to the southern. Indeed, seeing that the atmosphere 

 of the latter region is moister and shallower than that of the 

 former, it is probable that the phenomena would be modified. 

 A systematic observation of the Aurora Australis at a num- 

 ber of stations in high latitudes is therefore desirable. 



Whether or not there is any connection between auroral 

 exhibitions and the weather is a disputed point. Tromholdt 

 believes that such a relationship is probable {Under the 

 Rays, 1,283). He says, that, "however clear the sky, it 

 always became overcast immediately after a vivid exhibition, 

 and it generally cleared again as quickly" {Under the Rays, 

 1,235). Payer declares that brilliant auroras were generally 

 succeeded by bad weather {Voyage of Tegelhoff, 1324), but 

 that those which had a low altitude and little mobility ap- 

 peared to precede calms. Eoss remarks of a particular dis- 

 play "that it was followed by a fall of snow, as usual" 

 {Rosses Voyage, 1312). Scoresby appears to have formed 

 the opinion that there is a relationship indicated by 

 his experience. It is therefore allowable to regard the ulti- 

 mate establishment of some connection between these two 

 phenomena as a possible contingency. If, then, we look at 

 the eleven-year cycle of auroral intensity from the meteoro- 

 logical point of view, it assumes a new interest; for these 

 periods may coincide with the cycles of wet and dry seasons, 

 which some meteorologists have deduced from the records of 

 our Australian climate, and the culmination of the one 

 might be related to some equivalent change in the other; 

 for if a solitary auroral display be followed by a lowered 

 sky, surely a period of continuous auroras might give rise to 

 a period of continuous cloudy weather, with rain and snow. 

 Fi'itz considers that he has established this eleven-year cycle 

 upon the strength of auroral records extending from 1583 to 

 1874, and his deductions have been verified by others. 



In January, 1886, we had a widespread and heavy rain- 

 fall, and also an auroral display seen only at Hobart, but 

 which was sufficiently powerful to totally suspend cgmmu- 

 nication over all the telegraph lines situated between Tas- 

 mania and the China coast. This sensitiveness upon the 

 part of the electric currents to auroral excitation is not novel, 

 for long experience on the telegraph-wires of Scandinavia 



has shown that there is such a delicate sympathy between 

 them that the electric -wires there manifest the same daily 

 and yearly periods of activity as those that mark the auroras. 

 The current that reveals itself in fire in the higher regions 

 of the atmosphere is precisely the same current that plagues 

 the operator in his office. Therefore in the records of these 

 troublesome earth-currents, now being accumulated at the 

 Observatory by Mr. Ellery, we are collecting valuable data, 

 which may possibly enable the physicist to count the unseen 

 auroras of the Antarctic, to calculate their periods of activ- 

 ity and lethargy, and again to check these with our seasons. 

 But it need hardly be said that the observations which may 

 be made in the higher latitudes, and directly under the rays 

 of the Aurora Australis, will have the greater value, because 

 it is only near the zone of maximum auroral intensity that 

 the phenomena are manifested in all their aspects. In this, 

 periodicity of the southern aurora I have named the last 

 scientific problem to which I had to direct your attention ; 

 and I would point out, that, if its determination should give 

 to us any clew to the changes in the Australian seasons 

 which would enable us to forecast their mutations in any 

 degree, it would give to us in conducting those great inter- 

 ests of the country which depend for their success upon the 

 annual rainfall an advantage which would be worth, many 

 times over, all the cost of the expeditions necessary to estab- 

 lish it. . 



Finally, there is a commercial object to be served by Ant- 

 arctic exploration, and it is to be found in the establishment 

 of a whaling trade between this region and Australia. The 

 price of whalebone has now risen to the large sum of $10,000 

 a ton, which adds greatly to the possibilities of securing to 

 the whalers a profitable return. Sir James Eoss and his 

 oflfi-cers have left it on record that the whale of commerce 

 was seen by them in these seas, beyond the possibility of a 

 mistake. They have stated that the animals were large and 

 very tame, and that they could have been caught in large 

 numbers. Within the last few years whales have been get- 

 ting very scarce in the Arctic; and in consequence of this 

 two of the most successful of the whaling-masters of the 

 present day, Capts. David and John Gray of Peterhead^ 

 Scotland, have devoted some labor to collecting all the data 

 relating to this question, and they have consulted such sur- 

 vivors of Eoss's expedition as are still available. They have 

 published the results of their investigations in a pamphlet, 

 in which they urge the establishment of the fishery strongly, 

 and they state their conclusions in the following words: 

 " We think it is established beyond doubt that whales of a 

 species similar to the right or Greenland whale found in 

 high northern latitudes exist in great numbers in the Ant- 

 arctic seas, and that the establishment of a whale-fishery 

 within that area would be attended with successful and 

 profitable results." It is not necessary for me to add any 

 thing to the opinion of such experts in the business. All I de- 

 sire to say is, that if such a fishery were created, with its 

 headquarters in Melbourne, it would probably be a material 

 addition to our prosperity, and it would soon increase our 

 population by causing the families of the hardy seamen who 

 would man the fleet to remove from their homes in Shetland 

 and Orkney and the Scotch coasts, and settle here. 



In conclusion, I venture to submit that I have been able 

 to point to good and substantial objects, both scientific and 



