Feb. 7, 1889] 



NATURE 



341 



either writes extravagantly, or that, in describing the 

 social, industrial, and other characteristics of the colony, 

 they have allowed themselves to be unduly swayed by 

 mere feeling. They have, of course, a good deal to say 

 about the Maoris, and it is worth notmg that each refers 

 to habits and physical conditions which cannot but tend 

 to hasten the decay of that interesting race. A strong 

 liking for whisky is unfortunately characteristic of most 

 Maoris, and Mr. Payton remarked that the state of 

 drunkenness appeared to have a great fascination for 

 them. " I once saw a Maori that I knew," he says, 

 " walking up and down the veranda of an hotel, and 

 looking very much disgusted about something. On my 

 asking him what was the matter, he told me he had had 

 thirteen glasses of whisky, and couldn't get drunk ! " 



LETTERS TO THE EDITOR. 



[ The Editor does not hold himself responsible for opinions ex- 

 pressed by his correspondents . Neither can he undertake 

 to return, or to correspond with the writers of, rejected 

 manuscripts intended for this or any other part of Nature. 

 No notice is taken of anonymous communications. ] 



Solar Halo. 



Between i and 2 p.m. of January 11, a solar halo, so 

 remarkable as to deserve some notice in the columns of 

 Nature, was observed and sketched by myself and several of 

 my pupils. The mock suns A, B, and D (see diagram below), 

 appeared to be at the usual distance of about 22^" from s, and 

 the halo at E about the same distance from D. 



A and B were quite bright, but D and E were nearly twice as 

 brilliant, and blazed with gorgeous prismatic colours. 



The parhelic circle — observed by Prof. William Ellis on April 

 I, 1886 (Nature, vol. xxxiii. p. 535)— was very bright. It 

 extended only from the mock suns A and B outwards from s to 

 about 120° from the latter ; and on the right branch of this 

 circle was another mock sun (not shown in diagram) at the dis- 



tance of about 90° from B. This last sun, as well as the visible 

 portions of the parhelic circle, was formed of pure white light, 

 and the latter was everywhere parallel with the horizon. 



But perhaps the most remarkable part of the phenomenon 

 was the forking of the arc c E d at the ends c and d, and the con- 

 cave recurving of the arc a D b (convex to s at d) at the ends 

 a and b. These forkings and recurvings were very distinctly 

 visible at about 1.30 p.m., traced in fainter prismatic hues. 



There was a light cloudy haze covering the southern two- 

 thirds of the sky, while the remainder was clear. Calm moderate 

 weather both preceded and followed the phenomenon for some 

 days. Evan McLennan. 



Brooklyn, Iowa, U.S.A., January 14. 



[The altitude of the sun is not given, but (according to Bravais) 

 it must have been less than 30°, because of the extreme vividness 

 of the tangent arc to the halo of 46°. This also accounts for the 

 "recurved" appearance of the tangent arc to the halo of 22°. 

 The apparent bifurcation of the halo of 46° is too rudely drawn 

 to afford the means for a rigorous investigation. As sketched, 

 it may be due solely to diversity of inclination {balancemenl) of 

 the axes of the ice-crystals. — Ed.] 



Seismic Disturbance at Venezuela. 



About the middle of November 1888, there was a notabl ^ 

 seismic disturbance in several places of Northern Venezuela. 

 On the 13th, at 4h. 30m. a.m., a rather heavy concussion was 

 felt at Caracas, ana eastward as far as Rio Chico, where it 

 caused some damage. On the 17th, two shocks were noticed at 

 Cumana, viz. at 5h. 8m. a.m. and 2h. p.m. It is reported that 

 their force diminished towards the east, so that they were 

 scarcely perceptible at Carupano. On the same day two shocks 

 (ih. 4Sm. and 5h. 15m. p.m.) damaged in a somewhat serious 

 manner a large number of houses at Guanare (69° 20' W. of 

 Greenwich, 8 45' N. lat.); two more were felt at the same 

 place on the 18th at 3h. p.m., and on the 19th at ih. lom. a.m. 

 The ultimate sign of the paroxysm was obser\'ed at Caracas on 

 the last-named day, a few minutes before five o'clock in the after- 

 noon. The zone of disturbance extended from Carupano to 

 Escuque (63° to 70° W. of Greenwich), and embraced the whole 

 mountainous part of Northern Venezuela. In some cases the 

 wave-motion is said to have been plainly north-east to south- 

 west ; but the maximum of disturbance (first shock at Guanare) 

 showed decidedly a direction from north to south, as results 

 from the numerous cracks in damaged walls and the way in 

 which free-standing objects were thrown off their bases. The 

 clock at the telegraph station, which hangs on a wall running 

 east to west, was likewise instantly stopped. Dr. Lisandro 

 Alvarado, a physician who resided at Guanare, who communi- 

 cated these facts to me, informs me at the same time that the 

 cracks emerge in an angle of from 75° to 80°. It is therefore 

 very likely that the centre of the shock was not far from Guanare 

 towards the north, where the crystalline schists of the Cordillera 

 break through the overlying clay-slates and Cretaceous rocks, 

 which form the northern margin of the great plains or llanos of 

 Venezuela. Guanare lies on the very edge of these plains 

 (185 metres above the sea), where the Cretaceous formation rather 

 abniptly is met by the extensive deposit of conglomerate which 

 covers the plains. Any disturbance in the raised strata forming 

 the southern slope of the Cordillera will thus m.anifest itself with 

 particular intensity in the vicinity of this border-line. The whole 

 disturbance belongs, of course, to the class of tectonic earth- 

 quakes, as, indeed, do all those which happen now and then in 

 this country. A. Ernst. 



Caracas, January 6. 



Opportunity for a Naturalist. 



Captain Juan Page, of the Argentine Navy, who is now in 

 London, and read a paper on the exploration of the Rio 

 Vermejo and Rio Pilcomayo at the last meeting of the Royal 

 Geographical Society, has undertaken a new expedition for the 

 survey of the Pilcomayo from the Parana to the frontiers of 

 Bolivia. Captain Page would be glad to give a place on the 

 staff of this Expedition to a naturalist, who would thus have an 

 opportunity of investigating the almost unknown fauna and flora 

 of the Gran Chaco, through which the Pilcomayo runs. The 

 Expedition will start from Buenos Ayres in June next, and be 

 absent about six months. The naturalist would have to find his 

 passage out to Buenos Ayres, and home, and his own equip- 

 ment and collecting-materials, but on joining the Expedition 

 would be free from charges. I should be glad to put any 

 qualified person who might wish to avail himself of this ex- 

 cellent opportunity of exploring a most interesting country in 

 communication with Captain Page. P. L. Sclater. 



Zoological Society of London, 3 Hanover Square, 

 London, W., February 4. 



Mass and Inertia. 



Dr. Lodge (Nature, January 17, p. 270) seems to have 

 misunderstood the bearing of my letter on mass and inertia 

 (January 10, p. 248). 



I was careful to point out that my remarks on the advantages 

 of ayi?rf<--time-length system of units had reference solely to pro- 

 cedure in teaching. Dr. Lodge, fai'ing to observe this, objects to 

 the suggestion because it does not immediately afford an absolutely 

 permanent, universal unit of force. It was not intended to do 

 so. Anyone who has learnt dynamics and attained clear ideas, 

 appreciates the convenience of the ///^-r/Za-time-length system 

 for the purposes of the record. But the teacher's business is 

 with those who have not yet learnt, but who, knowing nothing 



