2?6 



NA TURE 



[July 4, 1895 



An angled spectrum of curved course may also develop by pro- 

 gression through the middle zone, beginning below, and attaining 

 its chief development in the upi>er half of that side, passing only 

 a little way l)eyond the middle line above. In one case this 

 was preceded by a transient angled star near the ]xiint of com- 

 mencement, and its early stage was accompanied by inhibitory- 

 loss at the margin of the field, outside the region in which the 

 discharge commenced. 



Although discharge never occurs at the central ]»int, it 

 may occur around it, as a circular zigzag, surrounding a round 

 object looked at — an instructive example of the fact that the 

 <lischarge may be related to the central effect of actual retinal 

 stimulation. Analogous to this " jjericentral" spectrum, is one 

 that takes the form of an arch above the central region, which 

 may sejxirate into two [arts at the middle line. As an instance 

 of the strong tendency there is to regard the spectrum as an 

 objective thing, a memlwr of the medical profession, when asked 

 to draw that which he saw, sent a drawing of his eye surmounted 

 by an angled corona. These forms again indicate disturbance 

 in centres in which there is no half-field representation. Besides 

 other forms, an angled spectrtmi sometimes a|)pears near the 

 outer temporal edge of the field, anil extends outwards for a 

 short distance and then curves downwards, never upwards. Such 

 a peripheral sixiclrum always seems to the subject to begin at 

 the extreme edge of the field and extend outside it. In one case 

 it was drawn as attached to the junction of the upjjer and lower 

 eyelids. 



It cannot be doubted that, by the study of these subjective 

 symptoms, much will ultimately W learned regarding the function 

 and mmle of action of the cerebral visual centres. Whatever 

 the drawbacks to observation through the consciousness of 

 another person, knowledge can be gained in no other way of the 

 action of the higher centres of the brain, and the time must 

 come when the physiological knowleilge which can be gained 

 only through the effects of disease and the disturbance of func- 

 tional derangement, will receive more attention. The facts of 

 these spectra, when studied in their detail, compel the conclusion 

 that they occur in centres in which function is related to the con- 

 joint fields, and in these to a central and a peripheral region and 

 to a medial zone between the two : that the chief relations are 

 central and peripheral : llmt outside the central region there is a 

 one-sifled relation, but that there is no distribution of function 

 at all ci>rres|K)nding to the division of the fields at the medial 

 line. The dominant rekilion is concentric, and the indications 

 afforded by the absolute one-sided loss caused by destruction of 

 one occipital lobe, has no reflection, positive or negative, in 

 these results of spontaneous central activity. 



HIGH-LE VEL METEOROLOGICAL STA T/ONS} 



(~\^V. of the greatest drawbacks to a full understanding of 

 ^-^ meteorological ])henomena is that the obser\ations on 

 which we tjose our knowledge are generally made close to the 

 ground in the most restricted air-stratum ; whereas the general 

 atmospheric movements, iKjth in velocity and direction, arc 

 much UKKlified in the lower strata, and the air surrounding and 

 in contact with the earth differs greatly Uith in temperature 

 and humiility from the free air. The more strongly agitate<l 

 upix-T strata react i>n the lower in many ways, and a knowledge 

 of the m'lvcment of the moderately high atmospheric layers is 

 of great importance for the theory of the general circulation of 

 the atmosphere, and pr.ictically for our weather forecasts, since 

 the forces which develop storms have their origin and sphere of 

 action within two or three miles of the earth. 



If the atmosphere were only in complete e<|uililirium, then 

 the few irregular observations, a.s regards time and place, which 

 have been made in balloons, would give some ilala on which 

 III Inu- general laws ; but, in the actual condition of con- 

 I tinenis and changes in the atmosphere, this can 



■ . anil the continuous observations reipiired of all 



;.,^ :-, at all seasons and in all weathers, can only be 



made on mountains, even (hough the conditions there only 

 approximate to those of the free air. In this way observations 

 on mountaini. complete those of the usual low-level stations. 



When the I'arth s surface rises in plateaux, the advantage of 

 cicvati'm alcive the sea —that is to say, the innnersion in the 

 upper strata is almnsl enlirely neutr.ilised, because still our 



instru!" 



placed in air masses which are affected by 



n paper, tiy Mr. A. l.awrcncc Rotrh. rend twforc the 

 icty. 



contact with the earth. For this reason meteorological obser- 

 \-atories should be located on high and isolated peaks. The 

 erection of such stations and the discussion of their observations 

 during the last fifteen years have contributed largely to the rapid 

 progress of the science of meteorology. 



The chief first order stations (those possessing self-recording 

 instruments, or where observations are made on an extensive 

 scale I which are located on niountain tops in the various 

 countries, will now lie briefly described. 



The first sununit station in the world was that establi.shcil in 

 1S70, jointly by the I'.S. Signal .Ser\ice and I'rof. J. II 

 Huntington, on Mount Washington, N.H., 6280 ft. above the 

 sea. I'rolKtbly nowhere else in the world has such severe 

 weather been experienced, the low-est temperature being here 

 often accompanied by the highest winds, indike the calms which 

 |)revail with intense cold at low levels. Vax instance, in 

 February 1SS6, with a teniix-rature of 50 degrees below zero, a 

 wind velocity of 1S4 miles an hour was recorded on .Mount 

 Washington. The tiovernmenl meteorological station on I'ike's 

 I'eak, at an elevation of 14,134 ft., was for many years the 

 highest in the world. Now both these stations are closed, 

 so that there seem to be actually in the United States but two 

 summit stations where meteorological observations are made 

 throughout the year, viz. : The Lick (Jbservatory. on Mount 

 Hamilton, California — primarily astronomical — and the Blue Hill 

 Meteorological Observatory in Massachusetts, situati-d at a very 

 moderate elevation. Prof. S. 1'. L^ngley's important researches 

 on the nature and amount of solar heat received by the earth 

 were carried on in 18S1 upon Mount Whitney, the summit of 

 which is 14,500 ft. above the sea. 



It is due to an .\merican institution that the highest meteoro- 

 logical station in the world is now in Peru, where the Harvard 

 College Observatory, several years ago, established an outpost at 

 .\requi|)a. In 1893, I'rof. Bailey succeeded in jilacing self- 

 recording instriMuents on the smumit of the neighbouring 

 volcano of El Misti, 19,300 ft. high, when a former station on 

 the side of Mount Chachani.near the snow -line, at an elevation of 

 16,650 feet, was abandoned. It is impossible for persons to 

 remain at these stations, so they were ])rovided with automatic 

 instruments which should give a continuous record of the chief 

 meteorological elements during two weeks. .Sever.il times a 

 month one of the Obser\atory staff climbs the mountain in 

 order to wind the clocks and change the register sheets, at the 

 Slime time making a check reading of standard instruments. 

 Breaks in the record occur, owing to imforeseen stoppage of the 

 instruments, or inability to make the .ascent at the appointed 

 time. 



France stands unrivalled in her superb chain of summit 

 stations on the I'uy de Dome (4800 ft.) in Auvergne, on the 

 I'ic du Midi (9440 ft.) in the Pyrenees, on the Mont \'entoux 

 (6250 ft.) in Provence, and on the Aigoual (5150 ft.) in the 

 Cevennes, whose construction has cost the natiiinal and pro- 

 vincial Ciovernments hundreds of thousands of dollars and 

 years of time. They are generally defective in having no co- 

 operating base stations, and their observations have not been 

 published in detail. In 1890, M. \'allol, a devoted .\l|>inist 

 and meteorologist, established several stations on and near Mont 

 I{|anc, from which records have lieen obtained each sunnner 

 since. The highest of these stations, at the Kochers des Bosses, 

 14,320 ft., is provided with many self-recording instruments 

 0|Kraling two weeks without attention, which are lookeil after 

 by the owner or hisguides e.ich week or twn during the summer. 

 The Observatory of M. Janssen, sunk in the snow on the very 

 lop of Mount Blanc, 1460 ft. higher, is not yet in operation, 

 but a meteorograph has been made for it in Paris, which will con- 

 tinuously record all the meteorological elements during a 

 periodof three months without atlenlion. A similar inslruuient 

 is being constructed at Blue Hill, by .Mr. Fergusson, for Prof. 

 Pickering's station im F.I Misti. 



On the F.iffel Tower In Paris are inslrunients 980 ft. above 

 ihe ground, which give more nearly the condilions i)revailin(J in 

 the free air than do any others permanently al this elevation. 

 They record at the Central Meteorological Office, a ipiarler of a 

 mile distant, si<le by side with .similar inslrunients exposed near 

 the grouml. 



.Among Ihe ( lerman and Austrian stations, that on ihe 

 Soindilick, a peak of the .\uslrian .Mps, 10,170 ft. high, ami the 

 highest permanently occupied observatory in lairope, slan<ls 

 preeminent, having furnished very valuable results under Dr. 

 Ilann's direction. 



NO. 1340, VOL. 52] 



