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large proportion of its original activity. On testing it, the of radium are brought to light, it would be simpler to ca. activity was found to have reached a small and nearly con- it radium E and to call the a ray product (polonius stant value. Rough observations, however, which I had radium F.

E. RUTHERFORD. made from time to time indicated that the rate of decay McGill University, Montreal, January 24. of this polonium was certainly not very different from that of radium E. More accurate experiments will be required

Indian and South African Rainfalls, 1892-1902. to settle the question definitely, but I think there is little doubt but that their rates of decay will be found to be Mr. J. R. SUTTON, of Kimberley, rendered a sign. the same.

service to South African meteorology in his “ Introductice Polonium, radio-tellurium, and radium E have very to the Study of South African Rainfall ” (Trans. S... similar radio-active and chemical properties. Each gives out Philosophical Soc., December, 1903), but when he state only a rays, and each is deposited on a bismuth plate placed that south-east winds are rare on the south-east coast ; in the active solution. The probable identity of their rates South Africa, and that the rainfall of the greater part 1 of decay, taken into conjunction with the similarity of the tableland and south-east coast comes from some norther their radiations and chemical properties, shows that the radio- direction (NATURE, November 3, 1904), it is difficult t active constituent present is in each case the same. We may follow his conclusions. Most, if not all, of those wr thus conclude that the active substance present in polonium have studied South African rainfall will, I think, agra and radio-tellurium is a decomposition product of radium with me that the facts do not bear this interpretatior and is the sixth (or, as we shall see later, probably the Least of all is it the case that there has been nothing tha seventh) member of the radium family.

can properly be called a drought, in the sense of Sir ! The main objection, in the past, against the identity of Eliot's address, within the past fifteen years in South polonium and radio-tellurium has rested on the statement Africa. In all the summer rainfall areas of South Africa of Marckwald that a very active preparation of his sub- | viz., over the bulk of the subcontinent, drought has pre stance did not lose its activity to an appreciable extent in vailed during recent years, and in some localities it has six months. Unless very special methods were employed, been terribly severe. it would be difficult to determine with accuracy the varia- During twenty years I have travelled over every part tion of the activity for such very active material. The South Africa except the desert areas, and I have resides specimen of radio-tellurium obtained both by Meyer and continuously in those parts where there is most rain arı Schweidler and by myself undoubtedly does lose its activity forest. I have heard the rain and its mode of arriss fairly rapidly.

discussed in every locality and from every point of vies I have recently examined more carefully the product and these facts have convinced me that the summer raisradium D, and have found strong evidence that it is not a have their origin in the moist winds from the Indi.r single product, but contains two distinct substances. TI Ocean. The precipitation of the moisture contained parent product, radium D, does not give out rays at all, these humid air currents is caused by barometric depression. but changes into a substance which gives out only B rays, with normal cyclonic wind circulation, and it is the wires. and is half transformed in about six days. Unless proper to these depressions that give the appearance observations are made on the product radium D shortly rains coming from the north, north-west, west, &c. after its separation, this rapid change is likely to escape The following gives a brief account of the various stor detection. The work on this subject is still in progress, but types. In Cape Colony storms travel from west to ko the evidence at present obtained indicates that the active at all times of the year. As one would expect, they ju deposit from the emanation, after passing through the three more regular and better developed in the south than rapid stages, represented by radium A, B, and C, is trans- the north, and in Rhodesia than in the Northern Transva. formed into a rayless " product D, which changes ex- In the north during summer they may be replaced tremely slowly. D continuously produces from itself another westward travelling tropical storms. I sually it is ** substance—which may for the time be termed Di-which secondary with its thunderstorms, a whirl within a wh is transformed in the course of a few weeks and emits only which precipitates the greater amount of moisture ! B rays. This product D, gives rise to E (polonium). the southern portion of the subcontinent these storms

Since the activity of D, reaches a maximum value a few most cases pass across from west to east with their cent weeks after the production of D, and will then decay at the to the south, and thus their wind circulation shows at fore" same rate as D, the conclusion, previously arrived at, viz., winds from the north and north-west, then from the wes that D is half transformed in about forty years, still holds and south-west, and finally from the south and southese good.

In summer, when the south-east trade blows on to the The view that radium D is the active constituent present subcontinent with a monsoon effect, the wind reinir. in the so-called radio-lead of Hofmann has been very longer in the south-east quarter, and heavy rains as strongly supported by some experimental results recently frequently from the south-east or the south-west quartz obtained by Hofmann, Gonder and Wöln (Annal. der Physik, The portion of the barometric depression and its accum vol. xv., 3. 1904).

panying circulation which brings the wind will depend They found that preparations of radio-lead continuously the position of the locality, but I have never known t! produced an a ray product, which could be separated on a facts not to conform more or less closely to this type bismuth plate. This active product is probably radium E, wind circulation. A range of mountains across the sour" for they found it lost a large proportion of its activity in east rain-producing wind will, of course, increase ? one year. They found, in addition, that by certain chemical precipitation, and when once rain has started in the su: methods another distinct product could be separated which east quarter it will often continue for days with a stau gave out only B rays, and lost much its activity in south-east wind blowing like a south-west monsuon * • six weeks. This substance is probably the new radium in India. All this takes place on the eastern side of S. product D, already referred to.

Africa. The rain is greatest in amount where the * Debierne recently concluded that radio-lead and polonium wind from the Indian Ocean first strikes the hghem were identical, and proposed that the name radio-lead eastern land, and the rain gradually decreases in arr. should be dropped in favour of polonium. In the light of until the western deserts are reached. It is generally the above results, this position is not tenable. There is no north-west wind which starts the precipitation, but it doubt that the preparation of radio-lead in my possession, quite certain notwithstanding that the humid currents : and also that experimented on by Hofmann, contains a not come from the north-west. If, as Mr. Sutton be distinct substance which, as the parent of polonium, has suggested, the high upper current of the north-west and certainly as much right to a name as its offspring. The trade were the source of South African rains, then it moet radio-active substance in " radio-lrad ” has no more con- be natural to suppose that the rains would be best in nection with lead than Marckwald's active matter " radio- veloped on the north and western sides of South Africa tellurium " has with tellurium. The names both arose which is exactly the reverse of what actually takes place because the active matter was initially found associated South Africa lies on the border of the south-east tha. with these substances.

area. In summer South Africa, from Cape Town to the In order to avoid confusion, I have called the new radium Zambezi, comes entirely under the influence of the year product “radium D." If no further intermediate products | east trade winds; but in winter the southern portion

Cape Colony is subject to another type of weather, due to years of general good rainfall we had in South Africa. the passage of storms from the South Atlantic, the “ roaring În 1895 the drought set in at most South African stations. forties” of mariners. It is necessary very carefully to Further, in this droughty period there were two years of distinguish between these two weather systems. In the bad famine, viz., 1896 and 1899. These two years of one the storms bring winter rains to a small part of the famine in India were the two worst years of drought at cubcontinent, i.e. Cape Town and the south-west; in the many typical South African stations. At present we are other the storms precipitate the abundant moisture brought not in a position to obtain average figures for the whole by the trade winds from the Indian Ocean, more or less of South Africa, but nearly the same purpose will be served over the whole subcontinent.

by taking certain typical stations thus : This much of explanation is necessary in order to under- " At Bulawayo (Hope Fountain), in 1890-1, there was stand clearly the connection between the weather of India the heaviest rain on record, viz., 45 inches; all the foland that of South Africa. In studying this connection we lowing years have been years of drought except three years. have at the outset to eliminate the winter weather of the when the rainfall was barely above the average. south-west with its winter rains coming from the South At Johannesburg there were good rains in 1894, when Atlantic.

there were good rains in India, fair rains in 1895, and Sir John Eliot, in his reply to Mr. Sutton, very properly then drought, when there was drought in India. 1896 excludes the area of winter rains. I go further, and (one of the Indian famine years) was the worst year of esclude what Mr. Sutton has termed the area of spring and drought in Johannesburg. The great Indian famine of autumn rains. The latter are areas where, with the winter 1899 was represented by a bad drought 1898–9 preceding storms still prevailing and the summer south-easters com- the failure of the Indian monsoon by four months. ing in from the Indian Ocean, there is the most marked “ Natal rainfalls correspond closely with the Indian precipitation in spring and autumn.

We are

not in a rainfalls. While 1899 was the worst famine for many position to say how far these rains have been produced by years in India, 1899 and 1900 were the two worst years the tail-end of the retreating Atlantic storms or by the of drought ever experienced at Durban, in Natal, since head of the advancing humid south-east trade currents. meteorological observations were begun there in 1866. In The fertile country watered directly by the south-east trade 1900, the Durban rainfall was only 27 inches against an is comprised in sections x. to xv. of Mr. Sutton's rain- average of 41 inches. At Maritzburg, representing the fall areas, viz. the east of Cape Colony, Kaffraria, Basuto- inland Natal districts, 1899 was also a year of drought, land, the Orange River Colony and Natal, and, in addition, but the greatest deficiency was registered the following all the Transvaal, Rhodesia, and the Portuguese territory; year (probably chiefly due to the calendar year dividing the in fact, it is the whole of fertile South Africa with the seasonal year). prception of the southern and south-west coasts. In the

Again, at Grahamstown, Cape Colony, in 1899 there table below I give the mean of Mr. Sutton's figures for was under 20 inches against an average of 29 inches ; his sections x. to xv., comprising Eastern Cape Colony, at King William's Town in 1899, only 16 inches against Iranskei, Basutoland, Orangia, and Natal, and I add an average of 25 inches; while at Graaff-Reinet in 1899. the yearly rainfall from typical stations in the Transvaal there was only 9 inches against an average of 15 inches. and Rhodesia, as correct general average figures for these At all these South African stations, 1899, the great Indian territories are not available.

famine year, was the worst year of drought in recent

times!' Percentages of Rainfall in the Summer Rainfall Areas,

The rainfall curves for Umtata, Evelyn Valley, and 1891 to 1902 : Mean of Sutton's Sections x. to xv. Katberg show similar features, viz., severe South African 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901

droughts corresponding to the years of Indian famine, and

a general deficiency of rainfall corresponding with the 136 106 132 97 103 102 74 107 89 82

years of general deficiency of Indian rainfall. The rainfall

curve of Evelyn Valley (Fig. 1), however, is very remarkAnd correcting Sir John Eliot's table to purely summer

able. This is a forest station, and the observer a parrainfalls it will read thus:-

ticularly good one. I have elsewhere compared this

station to Cherapunji, in India. I founded this station in Period of general excess of rain. Period of general deficiency of rain.

1887, and it has since shown the heaviest rainfall on the Percentage variation

Percentage variation summer register. It lies in a cul de sac of the mountains Summer rainfall.

Suamer rainfall. facing the south-east at an elevation of 4200 feet. I have India S. Africa.

long regarded it as the typical southern station for the

S. Africa. 1892

A study of its yearly rainfall curve + 6

summer rainfalls. 1895

5 + 3 1893

shows how rain failed here in the most striking manner 1896 (famine). 16 3 1897 normal

previous to the Indian famine of 1896, and during and - 26

after the Indian famine of 1899. 1898

+ 7

With regard to Mr. Sutton's statement that there has 1899 (famine)... 27 been severe drought during recent

years in South 1900

18

Africa, there is abundant evidence to the contrary. 1901

A vear ago I wrote : “ In the Karoo the present drought 1902

5

7

is considered the worst during the last half-century. At

Hanover (Upper Karoo) during nearly a year there has These figures show more strikingly than those already

fallen only three-quarters of an inch, the normal yearly quoted by Sir John Eliot the intimate connection between

rainfall being 15 inches. The drought has lasted on and the rainfall of India and South Africa during the period off since 1896-8, and during the worst years cattle and 18 to 1902, and the connection would have shown better

sheep have perished in millions. In British Central Africa if xasonal instead of calendar years had been taken, since

the drought has lasted since about 1898 ; it is reported that the calendar year cuts into two unequal portions the South the Shiré Lake is now nearly dry. Last summer's crops Ariran summer rainfall. It will be noted that each Indian in the Transvaal, so sorely needed after the war, were a latnine year has been followed by one or two particularly complete failure, while in Natal, Rhodesia, and the country bad sears of drought in South Africa.

to the north there was in many places famine, and people It is a somewhat remarkable coincidence that, while the dying in places too remote to be reached by Government number of NATURE containing this discussion was on the

aid. a on its way to the Cape, I prepared my yearly forecast “When will the drought end? is now the great question of South African weather, and in that took occasion to for the country.

int out the very close connection of the two rainfalls Good rains have fallen recently all down the eastern during this period. I may perhaps crave your indulgence side and on the south coast of South Africa. This rain 1. reprisduce it, since it confirms so singularly Sir John has come as a precious mitigation of the drought. It may 1.lie's view. Speaking of certain typical stations I said :- be looked on as a favourable indication for a good season

* Sir John Eliot's paper shows that 1892, 1893, and 1894'-perhaps more favourable if it had come later. pop years of good rainfall in India. These were the last The local and other indications of an early ending of

1902

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the drought are favourable. It has definitely broken up turn to NATURE of November 3, 1904 (p. 15). I produce in Australia." (Weather forecast, dated November 23, the extract for ready reference : 1903.)

Appendix iii. of a report upon the basin of the Upper Writing a year later, November 23rd, 1904, I said : Nile, with proposals for the improvement of the river by * My weather forecast for last year (published in the Sir William Garstin, contains an interesting account of the Cape Times of November 23, 1903) indicated the expecta- variations of level of Lake Victoria Nyanza contributed by tion of a more or less complete break-up of the drought. Captain H. G. Lyons, the director of the Survey Depart. This forecast has been fulfilled. In many parts of South ment of Egypt. This lake has a water surface of about Africa, particularly towards the north, the drought has 68,000 square kilometres, and is situated about 1129 metres broken, and good seasons were experienced last year. In above sea-level. It is believed to be of shallow depth, and other parts the rains were insufficient to really break the lies for the most part of the year in the region of the drought. This was the case in the fertile conquered equatorial rain and cloud belt, the excess water draining territory' of Orangia, and over wide areas in Cape Colony. off at the Ripon Falls by the Victoria Nile. After referIn the Transkei drought remains unbroken. It is de- ence to the geology and climate of the region, a brief scribed as a drought of terrible severity, and one that has historical summary is given of the early lake levels as stopped all ploughing and killed from 50 to 60 per cent. observed by travellers and others visiting or residing by of the sheep in some of the districts. As was remarked it; this is followed by a detailed study and discussion of by a correspondent in the Cape Times a few days since, the various gauges. Some of the results obtained are as

follows :—The annual oscilla

tion of the lake is from 0.30 Inches

metre to 0.90 metre. Between of Rainoll

1896 and 1902 there was a fall of 76cm. in the average level, since followed by a rise of

56cm. The epochs of high 71,50

and low levels are given as :-1878, high level ; 1880 90, falling level ; 1892-5, temporary high level ; 1896-1902, falling level; 1903, rising

The kernel of this quotation 70

lies in the last six words : it shows the same correspondence with the Indian rainfall figures as the summer rainfall figures of South Africa.

D. E. HUTCHINS.

Cape Town, December 8. 62

Compulsory Greek at Maar Rainfall or

Cambridge. 60 44 60

Some years ago a young lady who was studying at Girton came to Bristol to spend a part of her first vacation after passing the “Little-go." She had never learnt Greek at school, but had been coached by an elder brother, who was at that time in residence at Cambridge; in about two months she obtained a knowledge of Greek sufficient to meet the requirements of the authorities at Cambridge.

While she was with us we paid a visit to the ncigh

bouring city of Bath, and I Fig. 1.- Rainfall, Evelyn Valley.

directed her attention to the motto which is inscribed on

the Roman baths there, viz. : 'No one not living here has any idea of the terrible condition existing in the Karoo and Eastern Province.

άριστον μεν ύδωρ. . The springs on most of the farms have utterly disappeared. Remembering her recent success in the “Little-go," i On one farm in the Cradock district with large lands, jokingly asked her the meaning of this inscription--not orchards, and a water-mill at the junction of two kloofs imagining for a moment that Cambridge compulsory Greek in the Sneeuwberg, the river beds are as dry as a street ; would be unequal to such an easy task; she was, howthe farmer has sold all his stock, and I actually saw the ever, unable to give the meaning of the words; she did water for household use brought some distance in a barrel. think she had

άριστον, but In former years the water-mill was in constant use for all opinion that she had in the course of her reading met the the surrounding country.

word 6dwp, but did not remember what it meant. Writing to me recently from Zomba, in British Central It may be well to add that the lady in question has great Africa, Mr. Clounie, the head of the scientific department, linguistic ability, and in due course obtained a good place speaking of last summer's rains, says : “ The wet season in the Modern Languages Tripos. from November to April last has been remarkably good, Do our ultra-classical friends really think that comand crops everywhere have been excellent. I think every- pulsory “ Greek" of this type is worth preserving? thing points to the end of the drought and a return to a

J. WERTHEIMER. period of good rains.”

Merchant Venturers' Technical College, As regards the drought further north, the reader may 1

Bristol, January 30.

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NOTES ON STONEHENGE.

The method employed by Prof. Gowland in the II.--ARCHÆOLOGICAL OBSERVATIONS AT STONEHENGE, excavation should be a model for all future work of 1901.

the kind. I have to express my thanks to the council SOON after Mr. Penrose and myself had made our of the Society of Antiquaries and Prof. Gowland for

astronomical survey of Stonehenge in 1901, some permission to use the accompanying illustrations showarchæological results of the highest importance were ing the operations and results. obtained by Prof. Gowland. The operations which Above each space to be excavated was placed a secured them were designed and carried out in order frame of wood, bearing on its long sides the letters to re-erect the leaning stone which threatened to fall, A to H, and on its short sides the letters R M L, each a piece of work recommended to Sir Edmund Antrobus letter being on a line one foot distant from the next. by the Society of Antiquaries and other learned bodies, By this means the area to be excavated was divided and conducted at his desire and expense.

into squares, each having the dimension of a square They were necessarily on a large scale, for the great foot. A long rod divided into 6-inch spaces, nummonolith, “ the leaning stone,” is the largest in Eng- bered from 1 to į6, was also provided for indicating land, Cleopatra's Needle excepted. It stood behind the depth from the datum line of anything found. the altar stone, over which it leant at an angle of In this way a letter on the long sides of the frames, 65 degrees, resting at one point against a small together with one on the short sides, and a number stone of syenite. Half-way up it had a fracture one- on the vertical rod, indicated the position of any third across it; the weight of stone above this frac- , object found in any part of the excavation.

[graphic][merged small]

ture was a dangerous strain on it, so that both Excavations were necessary because to secure the powerful machinery and great care and precautions stone for the future the whole of the adjacent soil had to be used. Prof. Gowland was charged by had to be removed down to the rock level, so that it the Society of Antiquaries with the conduct of the could be replaced by concrete. excavations necessary in the work. The engineering All results were registered by Prof. Gowland in relaoperations were planned by Mr. Carruthers, and tion to a datum line 337.4 feet above sea level. The Mr. Detmar Blow was responsible for the local 'super- material was removed in buckets, and carefully sifted intendence. Mr. Blow thus describes the arrange through a series of sieves 1-inch, -inch, 4-inch, and ments (Journal Institute of British Architects, 3rd f-inch mesh, in order that the smallest object might series, ix., January, 1902) :

not be overlooked. "A strong cradle of 12-inch square baulks of timber From the exhaustive account of his work given by was bolted round the stone, with packing and felt, to Prof. Gowland to the Society of Antiquaries (Archaeoprevent any marking of the stone. To the cradle were logia, lviii.), I gather three results of the highest fixed two 1-inch steel eyebolts to receive the blocks importance from the point of view I am considering. for two six-folds of 6-inch ropes. These were secured These were, first, the finding of an enormous number and wound on to two strong winches fifty feet away, ' of implements; secondly, the disposition and relative with four men at each winch. When the ropes were quantities of the chippings of the sarsen and blue thoroughly tight, the first excavation was made as stones; and thirdly, the discovery of the method by the stone was raised on its west side."

which the stones were originally erected. i Continued from p. 300.

I will take the implements first. This, in a condensed form, is what Prof. Gowland says about ment. We evidently have to deal with builders doing them :

their work in the Stone and not in the Bronze age. More than a hundred flint implements were found, But was the age Palæolithic or Neolithic? and the greater number occurred in the stratum of Prof. Gowland writes :chalk rubble which either directly overlaid or was on Perhaps the most striking features of the flint a level with the bed rock. They may all be arranged implements is their extreme rudeness, and that there generally in the following classes

is not a single ground or polished specimen among Class 1.-Axes roughly chipped and of rude forms, them. This, at first sight and without due considerbut having well-defined, more or less sharp cutting ation, might be taken to indicate an extremely remote edges.

age. But in this connection it must be borne in mind Class 11.-Hammerstones, with more or less well- that in the building of such a stupendous structure as chipped, sharp curved edges. Most may be correctly Stonehenge, the tools required must have been numtermed hammer-axes.

bered by thousands. The work, too, was of the Class III.-Hammerstones, more or less rounded. roughest character, and for such only rude tools were Some specimens appear to have once had distinct required. The highly finished and polished imple. working edges, but they are now much blunted and ments which we are accustomed to consider, and battered by use.

rightly so, as characteristic of Neolithic man, would In addition to the above flint implements were find no place in such work. They required too much found about thirty hammerstones, consisting of large labour and time for their manufacture, and, when pebbles or small boulders of the hard quartzite variety made, could not have been more effective than the of sarsen. Some have been roughly broken into con- hammer-axes and hammerstones found in the excavavenient forms for holding in the hand, whilst a few tions, which could be so easily fashioned by merely

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have been rudely trimmed into more regular shapes. rudely shaping the natural flints, with which the They vary in weight from about a pound up to six district abounds, by a few well directed blows of a and a half pounds. To these we have to add mauls, sarsen pebble.” a more remarkable kind of hammerstone than those On this ground Prof. Gowland is of opinion that, just enumerated. Their weights range from about notwithstanding their rudeness, they may be legiti40 lb. to 64 lb.

mately ascribed to the Neolithic age, and, it may be,

near its termination, that is, before the Bronze age, How came these flints and stones where they were the commencement of which has been placed at found ? Prof. Gowland gives an answer which every- 1400 B.C. by Sir John Evans for Britain, though he body will accept. The implements must be regarded is inclined to think that estimate too low, and 2000 B.C. as the discarded tools of the builders of Stonehenge, by Montelius for Italy. dumped down into the holes as they became unfit for Prof. Gowland guardedly writes :use, and, in fact, used to pack the monoliths as they “In my opinion, the date when copper or bronze were erected. We read :-“ Dealing with the cavity was first known in Britain is a very remote one, as occupied by No. 55 before its fall, the mauls were no country in the world presented greater facilities found wedged in below the front of its base to act for their discovery. The beginning of their applica. together with the large blocks of sarsen as supports tion to practical uses should, I think, be placed at least (p. 54).”. Nearly all bear evidence of extremely rough as far back as 1800 B.C., and that date I am inclined usage, their edges being jagged and broken, just as to give, until further evidence is forthcoming, as the we should expect to find after such rough employ- approximate date of the erection of Stonehenge."

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