Dec. 1 6, 1886] 



NA TURE 



153 



owing to the sounding-wire having been entangled in the 

 cross-rope by the twisting before it broke, the apparatus 

 it carried was recovered. This apparatus consisted of an 

 iron wire, to which were attached a number of metals of 

 low fusibility, like antimony, zinc, &c., together with pieces 

 of wood, india-rubber, sealing-wax, &c. By the melting, 

 burning, or fusing of some of these, it was hoped to ob- 

 tain a rough idea of the temperature. Above these came 

 a small net, containing what was christened the " auto- 

 matic chemical laboratory." This consisted of pieces of 

 blue and red litmus-paper, Brazil-wood paper, and lead 

 paper. With the assistance of my colleague. Dr. E. 

 Divers, I had planned a number of chemical tests ; but 

 from previous experience I had learnt the impossibility of 

 carrying out anything but the simplest of experiments 

 when working on the summit of a live volcano. 



At the second sounding, at a distance of about 100 feet 

 from the edge, bottom (side?) was reached at 441 feet. 

 The wire of metals, litc, came up without change, farther 

 than the softening and bending of the sealing-wax. The 

 automatic laboratory had a strong smell of the action of 

 acid vapours. The blue litmus was turned red, and the 

 lead paper was well darkened. Assuming the lead paper 

 to have been blackened by sulphuretted hydrogen, then, 

 as pointed out to me by I)r. Divers, the absence of this 

 gas at the surface, and the presence of sulphurous acid, 

 might be due to the decomposition of sulphuretted hydro- 

 gen by oxidation or by sulphurous acid in the presence 

 of steam. The presence of sulphuretted hydrogen would 

 indicate a relatively lou- temperature. 



At the third sounding, the line, which was a copper 

 wire, gave way at a depth of about 200 feet, carrying with 

 it a mercurial weight thermometer and other apparatus 

 which I had reserved for what I hoped to be the best 

 sounding. 



The fourth and last sounding was made, as measured 

 on the guy-rope, at a distance of about 300 feet from the 

 edge. In this case, the line, which was strong twine, 

 after striking bottom when nearly 800 feet of it had run 

 out suddenly became slack. On hauling up, 755 feet 

 were recovered. The end of this line was thoroughly 

 carbonised, and several feet were charred. Assuming 

 that the guy-rope was paid out at an angle of \y\ we 

 may conclude that the depth at this particular place 

 was at least 700 feet. It is probable that the greatest 

 depth is about 750 feet 



.■\ final experiment was to attach a stone to the end of 

 the cross-rope, and then throw it into the crater, with the 

 hope of hauling at least a portion of it up the almost 

 perpendicular face on the other side. Unfortunately the 

 line caught, and, in the endeavour to loosen it, it was 

 broken. 



Before we left the summit, we were very fortunate in 

 obtaining views of one side of the bottom of the crater. 

 This we did by cautiously crawling out upon an over- 

 hanging rock, and then, while lying on our stomachs, 

 putting our heads over the edge. The perpendicular side 

 opposite to us appeared to consist of thick horizontally- 

 stratified bands of rock of a white colour. The bottom 

 of the pit itself was white, and covered with boulders and 

 debris. Small jets of steam were hissing from many 

 places in the sides of the pit, while on our left, where we 

 had been sounding, large volumes of choking vapours 

 were surging up in angry clouds. 



.\fter this we descended the mountain, reaching our 

 hotel at 8 p.m., after 15 hours' absence. 



This concludes the narrative of a holiday e.xcursion, 

 partly undertaken with the object of making a few scien- 

 tific observations. The results which were obtained are 

 undoubtedly very few, while the labour which was ex- 

 pended and the risks which were incurred were very 

 great. All that we did was to solve a problem chiefly of 

 local interest, to learn a little about the nature of the 

 gases which are given off by one of the most active vol- 



canoes in this country, and to enjoy the spectacle of a 

 phenomenon which it is the lot of very few to witness 

 When a stranger gazes for the first time down upon the 

 burnt and rugged sides of an apparently bottomless pit, 

 which, while belching out enormous clouds of steam, 

 roars and moans, he certainly receives an impression 

 never to be forgotten. 



The recorded eruptions of Asama took place in the 

 years 6S7, 1124 or 1126, 1527, 1532, 1596, 1645, 1648, 

 1649, 1652, 1657, 1659, 1661, 1704, 1708, 171 r, 1719, 1721, 

 1723, 1729, 1733, 17S3, and 1869. This last eruption was 

 feeble, but the eruption of 1783 was one of the most 

 frightful on record. Rocks, from 40 to 80 feet in some of 

 their dmiensions, were hurtled through the air in all direc- 

 tions. Towns and villages were buried. One stone is 

 said to have measured 264 by 120 feet. It fell in a river, 

 and looked like an island. Records of this eruption are 

 still to be seen, in the form of enormous blocks of stone 

 scattered over the Oiwake plain, and in a lava-stream 63 

 kilometres in length. John Milne 



Tokio, October 10 



THE MATHEMATICAL TRIPOS^ 

 II. 



VERY important regulations came into effect in 1848. 

 The examination, as thus constituted, underwent 

 no further alteration till 1873, and the first three days 

 remain practically unchanged at the present time. The 

 duration of the examination was extended from six to 

 eight days, the first three days being assigned to the 

 elementary and the last five to the higher parts of mathe- 

 matics. After the first three days there was an interval 

 of eight days (soon afterwards increased to ten), and at 

 the end of this interval the Moderators and Examiners 

 issued a list of those who had so acquitted themselves as 

 to deserve mathematical honours. Only those whose 

 names were contained in this list were admitted to the 

 five days, and after the conclusion of the examination the 

 Moderators and Examiners, taking into account the whole 

 eight days, brought out the list arranged in order of merit. 

 No provision was made for any further examination cor- 

 responding to the examination of the Brackets, which, 

 though forming part of the previous scheme, had been 

 discontinued for some time. A very important part of 

 the scheme was the limitation, by a schedule, of the sub- 

 jects of examination in the first three days, and of the 

 manner in which the questions were to be answered ; the 

 methods of analytical geometry and differential calculus 

 being excluded. In all the subjects contained in this 

 schedule, examples and questions arising directly out of 

 the propositions were to be introduced into the papers, 

 in addition to the propositions themselves. Taking the 

 whole eight days, the examination lasted 44i hours, 12 

 hours of which were devoted to problems. 



In the same year as these regulations came into force, 

 the Board of Mathematical Studies (consisting of the 

 mathematical Professors and the Moderators and Ex- 

 aminers for the current and two preceding years) was con- 

 stituted by the Senate. Although the new regulations 

 had so strittly limited the subjects, and parts of the sub- 

 jects, which could be set in the first three days, they had 

 imposed no limitation whatever upon those which could be 

 set in the last five days, the subjects of examination 

 appearing in the schedule simply as pure mathematics 

 and natural philosophy. Accordingly, the first matter to 

 which the newly-constituted Board turned its attention 

 was that of restricting the subjects on which questions 

 should be set in the last five days of the e.xamination. 



It becomes necessary, therefore, at this point, to refer 



* Address delivered before the London Mathematical Society by the 

 President, Mr. J. W. L. Glaisher, M.A., F.R.S., on vacating the chair, 

 November ii, 1886. Continued from p. 106. 



