Jan. 24, 1884] 



NA TURE 



291 



consistent with the requisite strength. Hollow bricks, 

 light tiles, with papier-maM for internal decorations, 

 have been recommended as materials suitable for super- 

 structures. .At the present time the city of Manila, partly 

 through Government interference, and partly through the 

 desire of the inhabitants to reduce the chances of farther 

 disasters, presents a singular appearance of light super- 

 structures rising from old foundations. Iron roofs are 

 visible in all directions, whilst on the massive basements 

 of old cathedrals and churches upper stories of wood, 

 with cupolas and spires of corrugated iron, have been 

 erected. 



.Although the suggestions embodied in the above notes 

 are few in number, it is hoped that they may be of some 

 practical value. Without extending them, they show us 

 that, even though we may not be in the position to escape 

 from earthqualces by forewarning ourselves of their ap- 

 proach, we can at least mitigate the effects of these 

 disasters by proper construction. John Milne 



Tokio 



THE LATE ERUPTION OF VESUVIUS 



OUR visit to the crater of Vesuvius on January II, 

 1884, was a most interesting one. In my former 

 letter I gave the rough details of this new eruption as 

 well as could be ascertained from the base of the cone. 

 The lava that issued on Tuesday night continued to flow 

 till Wednesday evening, but seemed to have arrested its 

 progress about 10 o'clock that night, when I was in the 

 Atrio del Cavallo. This stream proved to have welled 

 out at the base of the little cone of eruption and to have 

 flowed across the solid lava plain in the crater of 1872, 

 and then to have poured down the north-north-west 

 slope of the cone till it reached the Atrio, across which it 

 extended but little. Within the crater of 1872 we have a 

 somewhat conve.x plain of lava, which is continuous with, 

 or, more properly, overlaps, the crater edges, except for 

 a short distance on the south-south-west side. The north- 

 east part of this is covered by the remnants of the crater 

 of January, 1882. Within this were a series of crater 

 rings that have since filled up to a certain extent the 

 cavity of 1882. For some time the vent has travelled 

 south, so that the present cone of eruption overlaps the 

 crater ring of January, 18S2, on its south side, whereas 

 there is a deep crescentic fossa between the present cone 

 and the north crater ring of two years since. The vent 

 was giving forth great volumes of vapour, and there was 

 an almost continuous fountain of fragments of molten 

 lava, which often attained the height of one or two 

 hundred yards. As a consequence much filamentous 

 lava, often as fine as cotton, was raining around the 

 crater, and as we sat there eating our lunch, it was so 

 covered with these rock fragments, that it required a long 

 climb on foot to make such a gritty meal palatable. The 

 ejectamenta are composed solely of lava in detached 

 pieces, ejected in a plastic state with a few bombs, con- 

 sisting of older solid lava fragments partially fused and 

 rounded on the surface, which is varnished irregularly by 

 the fluid magma that enveloped them. This indicates 

 that the lava is very near the top of the chimney, which 

 must be full, as it has been for some time. Photography 

 was no easy matter amidst this fiery bombardment, for 

 such was the abundance of the ejectamenta that we could 

 see how rapidly the cone of the eruption was growing. 1 

 made a rough calculation of the quantity of new material 

 expelled, and 1 think six cartloads in four seconds as 

 quite a fair estimate. The lava that had flowed was solid 

 and cold enough to allow my dog to cross it with ease, 

 though through a few cracks it was seen to be still incan- 

 descent, and a green staff thrust in immediately blazed. 

 The lava that was flowing in the direction of Pompeii is 

 still doing so in one or two points, apparently at the 

 same rate and place as two weeks since. 



Altogether this eruption seems to be of very little 

 importance, and during the last four years there have 

 been many similar ones. Prof Palmieri, in the Corriere 

 del Mattiuo of January II, prophesies a great eruption, 

 but on what grounds it seems difficult to make out. 

 No one would deny that such could occur and is not im- 

 probable ; but there seems to be no more reason now than 

 two months since. 



The smoke or vapour yesterday had, when seen by 

 reflected light, the same colour as usual, namely, a 

 salmon tint. The sky was very clear, and I looked at 

 the sun through this vapour, bearing in mind the recent 

 remarkable sunsets and green suns. The transmitted 

 light ranged from a burnt sienna brown to a dirty orange, 

 having much the same colour as when we look through a 

 dark London fog. I noticed that the light that traversed 

 the vapour column and fell on the opposite escarpment of 

 Monte Somma was of a colour that would be obtained by 

 mixing a mauve with about equal quantities of brown. 



Naples, January 13 H. J. JOHN.STON-LAVIS 



THE EGYPTIAN SUDAN AND ITS 

 INHABITANTS 



AS some degree of vagueness seems still attached to 

 the term Sudan, it may be well to state at once that 

 it is simply the Arabic equivalent of the older and more 

 intelligible expressions, Nigritia, Negroland, which have 

 in recent times somewhat unaccountably dropped out of 

 use. In its widest sense it comprises the more or less 

 fertile zone lying between the -Atlantic on the one hand 

 and the Red Sea and Abyssinian Highlands on the other, 

 and stretching from the Sahara and Egypt Proper south- 

 wards to the Gulf of Guinea, the still unexplored Central 

 Equatorial regions, and further east to Lakes .Albert and 

 Victoria Nyanza. This vast tract, which may on the 

 whole be regarded as the true domain of the African 

 Negro race, is commonly and conveniently divided into 

 three great sections: — (i) H'es/e/n SuJan, comprising 

 roughly the basins of the Senegal and Quorra-Binue 

 (Niger) with all the intervening lands draming to the 

 Atlantic; (2) Cciilral Sudan, comprising the basins of the 

 Komadugu and Shari with all the lands (Kanem, Bornu, 

 Baghirmi, Wadai) draining to Lake Chad; (j) Eastern 

 Sudan, comprising everything east of Wadai, that is 

 mainly the Upper and Middle Nile basin. 



Politicall) , this third section, with which alone we are 

 here concerned, has for some years formed part of the 

 Khedive's possessions, hence is now more generally 

 known as Es:yptia)i Sudan. Until 1882 it formed a 

 single administrative division under a Governor- General 

 resident at Khartum. But in that year a sort of Colonial 

 Office was created for this region, which was placed under 

 a Cabinet Minister and broken up into four separate 

 departments or divisions, each under a Hukumdar, or 

 Governor-General, directly responsible to the Minister for 

 Sudan at Cairo. The various provinces hitherto forming 

 the single administration of Egyptian Sudan thus became 

 distributed as under : — 



West Sud.\n, comprising Darfur, KorJofan, Bahr-el- 

 Ghazal, and Dongola, with capital Fasher. 



Central Sudan, comprising Khartum, Senaar, Berber, 

 Fashoda, anl the Equator (Hat-el-Istwa), with capital 

 Khartum. 



East Sudan, comprising Taka, Suakin, and Massowah, 

 with capital Massowah. 



Harrar, coinprising Zeyla, Berbera, and Harrar, with 

 capital Harrar. 



The complete development of this scheme has been 

 somewhat rudely interrupted by the successful revolt of 

 the " Mahdi," who has for the moment wrested the 

 greater part of the country from Egyptian control. But 

 should this arrangement be carried out after the restoration 

 of order, a further element of confusion will be introduced 



