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No. II.—Containing pp. 53—186, with Plates I—X, was issued on September 17th, 1884. No. IlI.—Containing pp. 187—244, with Plates XI—XIV, and 15 Woodcuts, was issued on April 22nd, 1885. No. IV.—Containing the Title-page, Index &c., was issued on Feb. 3rd, 1887. LIST OF PLATES. ———e I.—Isobaric Charts of average pressure illustrative of Mr. Blanford’s Theory of the Winter Rains of Northern India. II—X.—Charts illustrative of Mr. Eliot’s Account of the Monsoon Storms of June and November, 1883. XI.—Diagram illustrative of Mr. Pearson’s article on the Variations of Rainfall in Northern India during the Sunspot Period. XII.—Genus Phyllothelys. XITI.—Genus Hestias.* XIV .—Simuliwm Indicum. * The publication of the article for which this plate has been prepared, is deferred in consequence of the acquisition of fresh material since it was written. H. F, BLANFORD, Journ. As. Soc. Bengal, Vol. XLIII,: Ft. II, 1884. Pl i: NOVEMBER. (os DECEMBER. Lithographed at the Survey of India Offices, Calcutta, August 1884, ISOBARIC CHARTS OF AVERAGE PRESSURE. r.) nal witht ity yap wish ‘ abr a"y) : \ ’ 1 PA Se a ae t= = ' ‘ : ‘ re gt ae ss a > <> Pa) >? z a a a . a - Zee 2d California Academy of Sciences Presented by_ASiatic Society of _ Bengal. og Sa Sn LV ca ne eRe ye i Eman.) Asean, JOURNAL OF THE ASIATIC SOCIETY OF BENGAL. —f>-— Part II.—NATURAL SCIENCE. ——~ No. J].—1884. ——eoe eee I—The Theory of the Winter Rains of Northern India.—By Hunry F. Buanrorp, F. R. S., President, Asiatic Society of Bengal, Meteo- rological Reporter to the Government of India. [Received and Read March 5th, 1884. | (With Plate I.) It has long been a commonplace of meteorological hand-books, that the winter, or, as it is more frequently (but less accurately) termed, the north-east monsoon, is due to a reversal of those conditions which, in the summer season, set in movement a flow of air from equatorial regions towards the plains of Southern and Eastern Asia. But, beyond this general statement of fact, very little has been done towards working out the physical characteristics of this familiar phenomenon of the Indian winter ; and such vague conceptions as are implied in the popular theory, leave entirely unexplained the well-known occurrence of rain, about Christmas time, in Upper India; a region, which, according to . that theory, should then be the seat of a barometric maximum, the fount and source of the winter monsoon. Since the establishment of a Meteorological Department under the Government of India, has rendered it possible to study the weather of India as a whole, from day to day, some insight has been gained into 1 2 H. F. Blanford—The Theory of the Winter [No. 1, the phenomena which precede and accompany the cold-weather rainfall of Northern India. In each of the annual reports on the Meteorology of India, in recent years, two or three instances of this cold weather rainfall have been described and illustrated at some length ; and at the present time, although many important points still require further eluci- dation, it is at least possible to set forth some generalizations on the conditions which usher in the precipitation of the cold-weather rains, and on the probable source of the vapour which feeds them. The four charts on Plate I exhibit the average distribution of at- mospheric pressure in the months of November, December, January, and February. These charts, being based on the registers of duly verified barometers during the last seven years, corrected to a common standard and reduced to sea-level values from elevations, determined in all but a few exceptional instances, by actual spirit-levelling to the mean sea- surface, may be accepted as representing, with a near approximation to truth, the relative differences of pressure which characterize the winter months in India.* Certain characters common to all, may be regarded as distinctive of the season. The seat of highest pressure is in the neighbourhood of Peshawar. Whether this may be taken as indicating that the pressure on the highlands of Cabul is also greater than at similar elevations over the plains of India is, however, very doubtful. The situation of Peshawar on a plain of moderate extent, girt around with mountains, is such that the high pressure may be and very probably is a local effect of the cooled air, draining on all sides from the sur- rounding slopes and filling the basin from which its escape is much obstructed. A similar high pressure is shewn by some other stations near the foot of the N. W. Himalaya, of which Dehra is a notable example. The conditions of pressure at higher elevations over the Himalaya, will be noticed presently. The next feature to be noticed is that, throughout the winter months, the axis of average high pressure on the plains and plateaux of India, occupies nearly the same situation as that of low pressure at * Rigorously speaking any such representation must of course involve an element of unreality, which is the greater, the greater the difference of land levels in the area embraced in the chart ; and, where, as in the case of India, large portions of the area differ by 2,000 feet and upwards, this element attains to some im- portance. Although it may not seriously impair the value of the chart as an illus- tration of the pressure-differences or potentials which maintain the system of wind- currents, the fact that the lower strata of air, resting on low alluvial plains, have no horizontal extension to the higher plateaux and cannot therefore be directly and immediately influenced by the atmospheric pressure there existing, is one that must be kept in view in discussing the relation of the winds to the pressure-distribution. 1884. ] Rains of Northern India. 3 ‘the opposite season. It extends from Upper Sind across Rajputana and the Central India plateau to Chutia Nagpur; the pressure along this axis declining, more or less irregularly, from N. W. to 8. EH. To the north of this ridge, a trough of relatively low pressure on the Gangetic plain separates it from the higher pressure along the foot of the Hima- laya, and, in most years, the pressure in the Punjab is somewhat lower than that of Western Rajputana. On the other hand, to the south of this axis, the pressure falls gradually down to Cape Comorin and Tra- vancore ; being, however, considerably higher on the east than on the west coast of the peninsula. In fact, the isobars run down the peninsula almost parallel with the west coast. The low pressure area which runs down the west coast of the peninsula is prolonged to the north, up the Gulf of Cambay, producing a northward bend in the isobars of that region very similar to that shewn by them in the summer monsoon, but with reversed gradients. Hence the cold weather distribution of pressure may be not inaptly described as a reversal of that which characterizes the summer mon- soon; but, in the first place, the barometric differences between the extremes, and therefore the gradients effective in producing the monsoon current, are less than half as great, and, in the second place, the axis of high pressure across Northern India lies further south than its opposite in the summer monsoon. It lies well across the middle of the plateau to the south of the Ganges, instead of followimg the course of the river, or, as not unfrequently happens in the case of the summer trough of depression, somewhat to the north of it. Thus, both in summer and winter, low pressure tends to prevail in some part or other of the Gangetic valley and the Punjab; but in the summer the gradient declines towards the N. W., in the winter, to the 8S. E. There is reason to believe that this normal distribution of pressure is restricted to the lower strata of the atmosphere, that is to say, to the stratum less than 7,000 feet in vertical thickness, measured from the sea-level. Thus, for instance, a row of stations on the plains of the Punjab and Ganges, ranging from Peshawar down to Purneah, shews a small, but decided, fall of pressure from N. W. to 8. E., when all the mean readings are reduced to their equivalent values at the sea-level. But if the mean pressures of the hill-stations, Murree, Chakrata, and Darjeeling (all of which are between 6,000 and 7,000 feet, or a little over the latter elevation), be reduced to a common level of 7,000 feet, the gradient at that elevation is found to be slightly, but distinctly, re- versed ; Darjeeling, the easternmost station, shewing the highest pressure. 4, H. F. Blanford—The Theory of the Winter [No. 1, Sea-level Equivalents of Atmospheric Pressure on the Punjab and Gangetic Plains. November. December. January. February. ins. ins. ins. ins. Peshawar’ sdoicvsivtsivenis cS) dq 2 a ari ° fed) 3 oO wR A A = Fa = Peshawar and Derajat............... 5 | 046] 0°51 | 0°65 | 1°06 | 1:29 | 3:97 Hazara and Patwar ...............-.. 4 | 1:06 {| 1:50 | 1°57 | 2°64) 2°66 | 9°48 PP ROMT. COBDS oo. .0 000 ansoeees ets 11 | 018 | 0°60 | 0°77; 115 | 1:14] 3°84 MOET PUNGAD... 0.05.0 .0eces eos segent It | 0°07 | 0°58 | O91 | 0°95 | O95 | 3°46 Kangra, Sirmoor and Kumaon ...| 11 0718 | 1:01 | 2:10 | 2°80 | 2°54] 863 N. W. P. & Oudh, Western half*...' 24 0:06 | 0°33 | 0°81 | 0°66 | 0°57 | 2°43 Ditto ditto, Eastern half ...{ 15 0°10 | 015 | O66 | 0°55 | 0°34] 1°80 North Behar and Bhagalpore...... 5 | 0°08 | 010 |] 0°58 | 053 | 0-45 | 1°74 Northern Bengal ..................+5 8 | 0°34) 012! 0°43 | 0°79} 1:18 4 2°86 Assam and Cachar ............,..06 13 | 0°95 | 0°36 | 0°64 | 1:35 |} 3°45 | 7:00 Upper Sind ...... ..| 8 | 0:08] 0-16] 0:23] 0:37 | 0-44 | 1:28 Lower Sind, Cutch and Gujarat... 18 | 0°08 | 0°07 | O11 | 0:16] 0-06 | 0-48 UMA MADONUN MI ov. vce hae dec peocppice ces 20 0°09 | 0°27 | O11 | 0°31 | 015 | 0°93 Prombral India, &...0. 2... ..e cece ees 24 0-16 | 0119 | 0°42 | 0°40 | 0°23 | 1°40 Mirzapore and Chutia Nagpur ...| 14 | 0:22 | 0°13 | 0°58 | 0°78 | 0°57 | 2-28 OE re te | 050) O17,| 0°48 | 1:07 | 160 |. 8:82 The above table includes the whole of extra-tropical India, and it is only in a portion of this region that the cold weather rainfall can be regarded as a well-marked and regularly recurrent phenomenon ; having a distinct maximum, that is to say, in the winter or spring months and equally defined minima before and after. The variations, -shewn in the above table, are considerable, both as regards the total amount and the epoch of the maximum. It is on the N. W. Himalaya * The meridian of Lucknow is taken as the boundary. 10 H. F. Blanford—The Theory of the Winter [No. I, and on the hills of the Northern Punjab that these rains are most copious, and that the maximum falls latest; the precipitation frequently taking the form of snow at all but the less elevated stations. In the extreme north-west, they attain their maximum in March and April; for the April rainfall (not shewn in the table) is about equal to that of March at Peshawar and in the hills of Hazara, while that of May and June is insignificant. But south of the Salt Range, and on the plains of the Eastern Punjab, the rainfall of February and March exceeds that of April. Still further to the south-east, throughout the greater part of the Gangetic plain, the maximum occurs still earlier, wiz., in January ; and this holds good as far as Behar and the confines of Northern Ben- gal. This anticipation of the maximum is not due to the January rainfall of the Gangetic plain being heavier than that of the Punjab. On the contrary, it is rather less: but the decrease in a south and 8. H. direction is much less rapid in January than in the subsequent months. In Northern Bengal, even the January maximum has vanished; and while the average rainfall of that month is only shghtly less than in Behar and the eastern part of the N. W. Provinces, that of February is higher, and that of March shews a further considerable increase. So far, the course of the variation seems to resemble that of the N. W. Punjab ; but the further steady increase of the fall in April, May, and June shews that this resemblance is fallacious, and that we have here to do with a phenomenon of a different order, viz., the storm precipita- tion of the spring months, the characteristics of which are still more pronounced in the more easterly province of Assam. As a well-marked feature of the local meteorology, the cold weather rainfall does not extend, in an easterly direction, beyond the province of Behar. Turning now to the regions somewhat further south, but still, for the most part, without the tropic, we see that in Upper Sind the total fall of the five months is very small, notwithstanding that it represents nearly one-third of that of the year; and also that, as in the Derajat, it reaches its maximum in March. In Lower Sind, Cutch, and Gujarat, the whole precipitation of the season is insignificant; but a maximum is still faintly indicated in February, and the same is more strongly marked in Rajputana, where the fall is about double as great. In Rajputana, it would appear that the December rainfall is almost as great as that of March ; but this is mainly due to an exceptionally heavy rainfall in December 1877,* combined with the fact that the Rajputana registers extend over a shorter period than those of most other parts * On this occasion nearly five inches of rain were registered at Banswara, between 3 and 4 inches at Jhalrapatam and Ulwar, and over'2 inches at Kotah, Deoli, and Bhurtpore. 1884. ] Tains of Northern India. il ef the country. Ido not think, therefore, that, on the average of a long period of years, the November rainfall of Rajputana would be found to follow a different law of distribution from that of other pro- vinces around. In Central India, including those portions of the Central Provinces and the N. W. Provinces that extend between the Jamna and. the Satpura range, the total fall is again higher, with a maximum in January and February; and, still further east, in Mirzapore, South Behar, and Chutia Nagpur, it is again greater, with the maximum in February ; but this apparent retardation of the maximum is evidently due to the inclusion of the early spring storms which in Chutia Nagpur become of relatively greater importance ; and this is rendered further evident in the table for Lower Bengal. The conditions which determine the storm precipitation of the ‘spring months will be noticed elsewhere. Meanwhile, it results from the above analysis that the cold weather rainfall, as hete considered, is that which takes place chiefly on the north and east of the barometric depressions, which are occasionally formed, in the winter months, in North-Western India. It is most copious where normally the winter temperature is lowest, viz., on the N. W. Himalaya, It decreases rapidly to the south, and less rapidly to the south-east, and, in this latter direc- tion, it blends into and becomes with difficulty distinguishable from the rainfall of the spring storms, which are, however, a phenomenon of a different order. Having thus defined the area and noticed the general characteristics of the winter rainfall of North-Western India, I will return to the question of the origin of those barometric depressions which have been shewn to be the immediate precursors of the precipitation, or perhaps rather of simultaneous formation. The area above defined as that of the winter rains, is identical with that in which, as has long been known, the relative humidity of the air, instead of diminishing towards the interior of the country, increases with the increasing distance from the sea-coast. On page 203 of the Indian Meteorologist’s Vade Mecum (Part II, para. 109), I described this phenomenon as follows: ‘ In the maritime provinces (of India) there are but one (annual) period of maximum and one of minimum humidity; in the Punjab and in Central India and the North-Western Provinces, there are two annual maxima and two minima; and in the drier part of the first named province, the winter is the dampest season of the year y x % x. Stations on the coast line have, at all times of the year, a higher degree of relative humidity than those on the plains of the interior. But the rate of increase is very different at different seasons; and in consequence of the greater cold of Upper and extra-tropical India, in the first three months of the 12 H. F. Blanford—The Theory of the Winter [No. 1, year, the rule of increasing dryness with increasing distance from the coast holds good inland, only as far as Behar ; and thence to the Punjab the relative humidity of the atmosphere increases steadily. It appears to be higher also through Central India, north of the Satpuras, but the meteorological statistics of this tract have not yet been sufficiently worked out to enable us to fix the limits of the area of higher winter humidity.” The above passage was written in 1876, only a year after the meteorological data for the whole of India had been, for the first time, concentrated in one central office, and when the system of observation had been but recently extended to many stations in Rajputana and Central India. It is, therefore, desirable to set forth, in a tabular form, some excerpts from the further evidence which has since been put on record ; and, to this end, I give, in the following tables, first, the absolute humidity of the afr as represented by the proportion of vapour in 1,000 parts (volumes) of air, second, the relative humidity, and, third, the cloud proportion (in thousandths of the sky-expanse*) in each of the six months November to April for four series of stations, three passing successively from east to west (or north-west) and representing re- spectively the Himalaya, the alluvial plain, and the plateau which extends between the latter and the Satpura range; and the fourth passing from south to north, beginning with stations south of the Satpura range, and terminating in the Punjab. * The figures of the two latter tables are extracted from those of the average values of the several meteorological elements given in the Report on the Meteo- rology of India in 1881. 13 G8 | CEP | Shr | 88E | SOS | GEL | 68 | 9 | 89 | 49 | 49 | ZO] 9T] ST /6 | 8 | 6 | OL] 0&4 | Sg9'T| T Tpudyemey Z9S ; SYP | SPP | FOP | GOES | FIZ | cP | 8S | Z9 | 89 | 89 | OG | FL | ST | OL | OL | OL] TL | ATZ | 628 | rrr ‘qoXTRIG PIS | 98 | 68E | ES | 6FS | GST | OS | ZG | €9 | G9} GO| IG | SL | 22] 11,6 | 6 | OL} O69 | GIB J “eaermpnty Zee | ¥9G | SSE | S8a | Ges | LB | 9E! GG | GO| G9} 9 | LG] SL | ST | OL | OL | OT | ZT | 069 | Z88 | Sooyt00y LLT | bee.) OUG | Ive | ZZEy 29 PF 1 | 6919 | 79) FO | 69 | ST | PL | TL | OT | OT} ST | S98 4 BOG Lower etree ‘ATTLOIV Géo | 16d | SEE | G8Z | CELT | 16 | LE | OF, SS | 6E | 8G} SS] ST!) FL | TL] OL | OL} ZL | oss | GOS [tt SMougomT SPI | GST | 22e | S6T | SOL | 26 | 9 | 9F | 09 | 49 | 89 | 9] ST) SL | ZL | IL | SL | FT| OS | Zoe Jo “peqeyaery PST | LTS | OFS | Sas | SOT | OZL | 9G | SF | 4G | €9 | F9 | ZO] SL | ST | IL | OT] OT; ST | 89E | 49S [oC ‘seredeg €&6 | STS | SL4Z ' GHZ | L0G | OAT | GE | SP | SF | 09 | 09 | ZG] OL | HL | SL | SL | SL | ST | 408 | 64T Jo =a sree Seuqed OST | OFT | SIT | 22T | LOL | $6 | 9S | SG | 6S | 99} 69 | OL] TZ | OT | SL | SL | FL | ZT | G6e | Set J “qeoumg 3s OGE | 162 | Z6T | SIZ | FET | LEZ | ZO | SS | SO | GO| TZ | G4] 3S | SL} PL | SL | FL | SL | 94T | 99 srreeeescess Qrodurey1e g 7S OEE | PLS | OAT | SST | SET | OTS | ZO | SE | SS | 09 | 9 | 89] 4a | Tz | OL | FT | OT | O@ | G6 €& 5 ted woo eka 2 ‘e10sse = £96 | See | GET | LET | OGL | OZ | EL | 69 | 69 | OL | TL | FL] 8S | GS | ST | FL | ST | 0% | g9 8T asa Ot ce a ke fa PLP | OSE | SST | OST | OST | SFZ] 08 | 84 | 44 | SL} &4 | FL] SE | 46 | S| ST | LAT | Gs] O 9 rreeeereee DUBIST LOSUVG 3 = OcS | G6 | IPS | OTS | SSP | STS] OS | TS | 49 | SF | 6F | SFIOT}S |9 1} 19 | 4 | OSh | HRE'Q] CC Cony i S8é | SOF | GES | SIF | ISE | Sol] 4P | 8 | 8S} 19); 2 ,ss}or}s |4 19 |9 | 6 | OS oe aaa os eqeryey SSE | SLE | 19M | HE | OLE | GZT | ZH | GS | O9 | GF | 9G | SF] IT} 0LT|8 ;}8 |8 | OT] 084 | 690°9[ ereeees QOu yey > PID | TSS | G6S | 69S | Sev | GeV | 44 | 14184) 84 | 84) S4] SL] cL} 0L|6 | 6 | Bt | sae | stag Sureolreg 3 ee tk ae aly er ee | ee ta ts oe a RS Fag ee bay | Peete he te ie ele lets | sie) Si sie lye) 8 | B Pig |e |e [8 |e dBlia/ Fle SlseleziziFi/elsie)] es) 2 . - & = ) 5 5 ae oe ry) 5 B Rev| eee of ag bbe: | |g B m eo : Sia |e | & "TRB la lol] & mele qiaole| 5 < : g ® ees | oe : : e | 8 § 5B *‘SNOILVLG : ; s ‘009% yortodoad . 0 03 bye 8 g y20do01d pno[g WOTJVINJeS JO osvyuod1Eg er ® r," Ps ‘syquopy buady pun ~~ sayy 243 ur pypur UlaYyI4ON Ut pnojiQ fo uousodoug pun wp ay, fo hyypwungzy oaynjay puv aynposqgp wnapr [ No. 1, H. 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Toor, soeenese*> beer see eenaee ‘Tsuvy er ‘++ “SUOS.MO NT sev eerverees mpereress ‘euIng ener eee eer nne ee ‘grodjnqque eens ‘Bl O TV axecer™=$ INCOSE sere eeeeee ‘rndrey reeeeesCozoutly “+++ GyonuIee NT perenne ‘Tsuey f seen ‘euqng ‘ySVqriezey ‘SNOILVLG ‘(ponuyu0y) syjzuopg burudgy pun LOIULA OY WL DYPUT ULaYyQUONT UL pnojID fo uoyLsodoug pup wp ay, fo hzvprunzT aayvpoy pup aynjosqy way 1884.) Rains of Northern India. 15 The above table confirms and justifies the description already quoted from the Vade Mecum, and also the generalization just given, that the area of the winter secondary rainfall maximum coincides with that in which there is also a winter secondary maximum of relative humidity. But it also brings into prominence some further facts, which assist in throwing much light on the causes of the rainfall. In the first place, it is to be noticed that the increase of the relative humidity of the later months, as we proceed from Behar towards the Punjab, is due, solely, to the fall of temperature ; the absolute humidity being almost constant ; but the latter is decidedly lower on the high ground of Central India and Rajputana, south of the Gangetic plain, than on the latter and in the Punjab. These two facts, viz., the uniformity of the absolute humi- dity over the riverain tract, and its decrease on the higher ground to the south, indicate that it is mainly dependant on local evaporation ; being, in fact, furnished by the rivers, the undried swamps left by the autumnal floods, and, in no small degree, probably, by irrigation and the rich vegetation of the green winter crops. In the second place, it is to be observed that this riverain tract also coincides with the region of lower normal pressure, to the north of the axis of maximum pressure, shewn on the normal baric charts, on Plate Il. And lastly, the tendency to cloud formation follows, on the whole, the same laws of distribution as the relative humidity of the lower atmosphere, with, however, this important exception; that, except in April and to a slight extent in March, it is lower in the neighbourhood of the coast (in Lower Bengal), notwithstanding the higher relative humidity of the lower atmosphere, than in the Upper Provinces, where the rainfall generally originates. Now putting together the several facts thus independently elicited from the study of our registers, we arrive, I think, at the outlines of a consistent theory of the production of the winter rainfall. We have, in the first instance, steady evaporation over an extensive moderately humid tract, at a comparatively low temperature, it is true, but in an atmosphere, the stillness of which allows of steady diffusion of the vapour to high levels, and the consequent formation of cloud. The slight disturbance of the baric equilibrium which follows (since the vertical decrease of temperature in a cloud-laden atmosphere is slower than in a clear atmosphere), is succeeded by a gentle indraught of warmer and more humid air from the south; for the Himalaya bars access to northerly winds. A vortex is then rapidly formed, accompanied with an increased cloud-formation, and speedily followed by precipita- tion; which takes the form of snow on the hills, and of rain over the river plains. The rainfall is invariably followed by a cool wind, and a wave of high barometric pressure from the west, which I can only 16 F. Moore—Descriptions of some new Genera and [No. 1, attribute to a drainage of cool heavy air from the valleys of the hills surrounding the Punjab and the high lands of Beloochistan and Afghanistan ; air cooled by the precipitation on the mountains. If the above view be true, the stillness of the atmosphere, combined with the presence of a moderate evaporation, must be accepted as the condition which primarily determines the formation of barometric minima and the winter rains of Northern India. And this stillness is obviously due to the existence of the lofty mountain ranges which surround Nor- thern India, leaving free access to the plains open only to the south. Were the Himalayan chain absent and replaced by an unbroken plain, stretching up to the Gobi desert, it is probable that the winter rains of Northern India would cease ; any local evaporation in the Punjab and Gangetic valley would be swept away by strong dry N. EH. winds blowing from the seat of high pressure, which, in the winter months, les in Central Asia; and instead of the mild weather and gentle breezes which now prevail at that season, on the Arabian Sea, it would be the theatre of a boisterous and even stormy monsoon, such as is its local equivalent of the China Seas. Other and even greater changes of climate, that would supervene on the suppression of the Himalayan range and the consequent alteration of the summer monsoon, its preci- pitation, and the course of the land drainage thereby fed, it would be beyond the province of my present subject to discuss. II.—Descriptions of some new Asiatic Diurnal Lepidoptera ; chiefly from specimens contained in the Indian Museum, Calcutta — By Freperic Moors, F. Z.8., A. L. 8. Communicated by the Natura History SECRETARY. [ Received May 14th,—Read June 4th, 1884. | Family NYMPHALIDA. Subfamily Saryrina. Genus Ypruima, Hiibner. YPTHIMA MAHRATTA, n. Sp. Male and female. Upperside brown; forewing with a subapical bipupilled ocellus ; between which and the outer margin is a pale brown curved fascia as in Y. newara: hindwing with a very small subanal unipupilled ocellus. Underside pale whitish-brown, very numerously covered with short delicate pale brown strigee, which are uniformly disposed: forewing with 1884. ] Species of Asiatic Diwrnal Lepidoptera. 17 a brownish marginal fascia, which curves below the ocellus and extends up the disc towards the costa: hindwing with a very small apical ocellus, and two anal ocelli of the same size. Expanse 1,3, to 1,4, inch. Has. Deccan (Dr. Day). In coll. F. Moore. Allied to Y. ariaspa, Y. rura, and to Y. norma. Nearest to Y. norma, the type specimens of which are from China. Differs from the last species, on the upperside, in having a smaller ocellus on the fore- wing, and a single subanal ocellus on the hindwing. Underside with shorter and more numerous strige; both the apical and the two anal ocelli of hindwing are half the size of those in Y. norma. The hindwing also has a comparatively longer costal margin, which thus gives the apex and exterior margin less convexity. YPTHIMA APICALIS, n. sp. Male. Upperside pale brown: forewing with a small rounded bipu- pilled apical ocellus, above which is a distinct broad whitish streak : hindwing with two very small subanal ocelli, the upper one minute, the anal and apical ocellus of the underside being slightly visible from above ; across the middle of the lower discal area is a faint pale slight fascia. Underside pale brownish-ochreous, with indistinct darker brown uniformly disposed strigz : forewing with the apical ocellus and white upper streak as above: hindwing with a small apical and three lower ocelli, the anal one bipupilled ; an indistinct pale whitish fascia is trace- able across the disc above the lower ocelli. Expanse 12 inch. Has. Deyra Dhoon (Godwin-Austen). In coll. F. Moore. YPTHIMA KASMIRA, Nn. sp. Male and female. Upperside dark brown: forewing with a mode- rately small bipupilled apical ocellus: hindwing with two small subanal ocelli in male and, in female, a third minute anal ocellus. Underside purpurascent brownish-white, densely covered with uni- formly disposed purplish-brown strige : forewing with prominent apical ocellus : hindwing with prominent large apical and three lower ocelli, the anal one tripupilled. Expanse 6 12, 2 1% inch. Has. Cashmere (Capt. Hellard). In coll. F. Moore. YPTHIMA HOWRA, 0. sp. Male and female. Upperside brown: forewing with a bipupilled apical ocellus: hindwing with two small subanal ocelli, some specimens 3 18 F. Moore—Descriptions of some new Genera and [No. 1, of both sexes also having a smaller anal ocellus, all with a single pupil. Underside yellowish ochrey-white : forewing with the ocellus as above : hindwing with a very small apical ocellus and four lower ocelli, the two anal being geminated and the smallest. Both wings are crossed by ochreous-brown strige; with the three outer transverse fasciz on fore- wing, and an angulated discal fascia, as well as a sinuous marginal fascia, on the hindwing. Expanse g 12, ? 12 inch. Has. Calcutta. In coll. Ind. Mus., Calcutta, and F. Moore. Nearest to Y. hiibneri. Distinguishable from typical specimens (figured as Y. philomela, Hubner, Zutr. fig. 83-84), on the underside, by the yellowish ochreous-white ground-colour, and the transverse fasciz on the hindwing, as well as by the small size of the ocelli. YPTHIMA HORSFIELDII, n. sp. Male. Upperside dark olive-brown; discal area dusky ; subapical ocellus oval, bipupilled: hindwing with two medial and a minute anal ocellus. Female. Upperside: forewing with a large rounded ocellus: hind- wing with two larger medial, a small anal, and a medium-sized apical ocellus. Underside of male and female ochreous-white : forewing almost covered with dark vinous-brown confluent strige : hindwing very sparse- ly covered with slender brown strigze very similarly disposed to those in the typical Javan Y. pandocus: ocellus of forewing as above : hind- wing with two small apical, two larger medial, and two smaller anal ocelli. Expanse @ 1,45, 2 1,% inch. Has. Java. In coll. F. Moore. Subfamily NyMpHatin«. Genus Kurnaria, Hiibner. KUTHALIA ANDERSONII, n. sp. Male and female. Upperside dark umber-brown, palest in the female ; both wings with a marginal bluish-grey band, which extends very nar- rowly from the apex of forewing and widens across the hindwing to broadly above anal angle. Within and beneath the cells the black streaks are most distinct in the female; across the discal area are two indistinct dusky sinuous fascize widening from the costa of forewing, at which end the interspace is slightly paler in the male and distinctly peer in the female. Cilia white. - 1884] Species of Asiatic Diurnal Lepidoptera. 19 Underside ochreous-brown in male and yellowish ochreous in female ; the outer borders broadly suffused with purplish lilacine-white ; cell- ‘marks distinct ; across the disc of both wings are too dusky lunular fascise -with pale interspace, most distinct in the female, the fasciz being dis- posed across the middle of the disc. Expanse & 2+, ? 22 inches. Has. Mergui; Tavoy. In coll. Ind. Mus., Calcutta, and F. Moore. Nearest allied to H. cocytus, Fab. ; also to H. lepidea, Butler, and to EH. macnairit, Distant, Genus CrrrHocuroa, Doubleday. | CIRRHOCHROA ABNORMIS, 0. sp. Male. Upperside ferruginous-yellow : forewing with a medial discal transverse black lunular waved band, which is broadest at the costal end, a narrower submarginal sinuous band, and a nearly straight marginal line, the interspace from the submarginal band and edge of the wing be- ing suffused with black towards the apex ; an indistinct dusky streak at end of the cell: hindwing with a medial discal transverse angulated black lunular band, which is broadest at the costal end; a submarginal lunular line, and a slender nearly straight marginal line ; a row of minute black discal dots. Underside brownish-ochreous ; a transverse medial slightly purpurascent band, with waved suffused dusky lunular inner border and slender almost straight outer border, the band being quite narrow where it crosses from fore to hindwing and broadly dilated at the costal end on forewing and at anal end on the hindwing; contiguous to the inner bor- der of the band is a similar dusky suffused lunular fascia, the interspace being of a slightly pale yellowish colour; at end of each cell is a dusky double lunular mark, a similar double lunular waved line also extends from middle of the cell on forewing to below the cell on the hindwing ; outer border of both wings traversed by faint traces of a yellowish sub- marginal lunular band; on the forewing is a conspicuous and whitish apical patch, and on the hindwing is a row of very small blackish trans- verse discal dots. Expanse 23 inches. Has. Darjiling. In coll. F. Moore. Genus Ereaouis, Boisd. ERGOLIS TAPESTRINA, N. sp. Male and female. Comparatively smaller than [. merione ; outline of forewing more irregular. Upperside paler; with similar transverse sinuous lines on both wings, the two medial lines being somewhat nearer 20 F. Moore—Descriptions of some new Genera and [No. 1, together, the discal cordate marks having their outline of a uniform width, and being somewhat narrower transversely, thus leaving a slightly but perceptibly wider space between the contiguous lines ; the interspaces between the basal lines, the subbasal and medial lines, the discal cordi- form marks, and the marginal line and outer margin, are of a more dusky colour, and thus give the wings the appearance of being marked with alternately pale and dusky transverse bands. Underside also paler than in Hi. merione, with more regularly alternate pale and dark transverse bands. Expanse 1£ to 2§ inches. Has. N. W. India (Manpuri; Deyra Doon). In coll. F. Moore. ERGOLIS INDICA, 0. sp. Differs from typical Javanese specimens of Z. ariadne in its smaller size. Upperside of a duller colour, the markings more obscure and com- paratively less sinuous. Underside with paler interspaces between the bands, the apical border of forewing and the marginal border of hindwing ereyer, and comparatively broader. Expanse 13 to 14 inch. Has. Madras; Nilgiris; Bombay; Calcutta. In coll. F. Moore. Family LYCAANIDA. Genus ParapitHecops, Distant. PARAPITHECOPS GAURA, 2. Sp. Male and female. Upperside brown: forewing with a large white medial longitudinally oval spot, occupying the centre of the wing from middle of the disc to near the base ; a small brown dentate spot at upper end of the cell: hindwing with the apical and upper discal area broadly white and traversed by pale brown veins; a slender brown submarginal line enclosing a marginal row of brown spots. Cilia of forewing whitish posteriorly, of hindwing entirely white. Underside greyish white: fore- wing with a submarginal line composed of slender waved brown lunules, and a marginal line enclosing a row of small linear spots ; a slender indis- tinct brown streak at end of the cell, and three or four dots along the costal edge: hindwing with an irregular submarginal row of brown lunules, a marginal line enclosing a row of darker spots; a black spot at upper end of submarginal line, and a subbasal row of three smaller more or less dis- tinct black spots; a slender brown streak at end of the cell. Antennze black, ringed with white ; pale white beneath, third joint and tip of second black ; legs white, banded with black. Hxpanse ¢ 55, ¢ 1,4; inch. Has. Calcutta. Assam. In coll. Ind. Mus., Calcutta, and F. Moore. ~~ 1884.) Species of Asiatic Diurnal Lepidoptera. 21 Genus Meraispa, Moore. MEGISBA SIKKIMA, Nn. sp. Male. Differs from M. thwaitesii, on the upperside, in being of a darker violet-brown, and in the absence of the short oblique pos- terior white band on the forewing. Underside similarly marked to M. thwaitesu, except that on the forewing the black spot in middle of the cell is very minute, and there is a spot below the end of tho cell be- tween the middle and lower median veins in addition to the two dots, which are here placed beneath the lower median vein, whereas in M. thwaitesit the two latter dots, when present, are situated between the middle and lower medians. On the hindwing the three transverse sub- basal black spots are comparatively larger, the upper one with two con- tiguous black dots in front; the cell-spot is prolonged upward to the costal vein and also has some black dots below it, the apical black spot is of an elongated form, and the discal macular band is composed of broader quadrate spots. Expanse ~ inch. Has. Sikkim. In coll. Indian Museum, Calcutta. PATHALIA, 0. g. Closely allied to Megisba: forewing comparatively longer, and less regularly triangular in form: hindwing somewhat narrower, and with a slender tail at end of lower median vein. Venation similar. Second joint of palpi shorter, the third joint longer and more slender. Type, P. albidisca. PATHALIA ALBIDISCA, 0. sp. Male and female. Upperside dark violet-brown: forewing with a broad medial conical white patch, which extends obliquely from middle of the disc to posterior margin : hindwing with a broad white band cross- ing from the costal edge to near middle of the abdominal margin; an indistinct marginal row of pale-bordered brown spots. Underside grey- ish-white : forewing with some black spots along the costal edge, a brown streak at end of the cell, a discal transverse row of short oblique slender interrupted lunules, a submarginal sinuous line enclosing a mar- ginal row of indistinct spots: hindwing with a similar brown cell-streak, a discal zigzag series of broader lIunules, a sinuous submarginal line enclosing the marginal row of spots, of which the penultimate is large and black ; three equidistant subbasal black spots, a black spot on the abdominal margin above the lower subbasal, and a larger black spot at the apex ; tail in both sexes black, tipped with white. Cilia edged with 22 F.. Moore—Descriptions of some new Generr and [No. }, white. Body above black, antenne black annulated with white; palpi white, tip black ; legs white with black bands. Expanse # 14, ? 1,4, inches. Has. Chittagong; Kurdah, Orissa; N. W. Himalaya (Capt. Beckett). In coll. Indian Museum, Calcutta, and F. Moore. PATHALIA MALAYA. Lycena malaya, Horsfield, Catal. Lep Mus. E. I. C. p. 70 (1828), 9. Has. Java. (Horsfield collection.) Genus Logania, Distant. LOGANIA SUBSTRIGOSA, 0. sp. Upperside dark violet-brown. Cilia white between the veins. Cos- tal edge of forewing with a minute white dot at end of the veins. Underside purplish white, crossed by a few ochreous-brown short strige, and with a thicker streak across middle and end of the cell, and in a zigzag submarginal series; also a marginal series of black spots on the forewing, and a lunular streak on hindwing ; a black costal spot also on the hindwing ; and the outer marginal border of both wings is ochreous- brown. Body, antenne, and legs above brown ; palpi, legs, and abdomen beneath white. Expanse 5% inch. Has. Mergui. In coll. Indian Museum, Calcutta. LOGANIA MARMORATA, 0. sp. Upperside pale purplish violet-brown : forewing with the basal half, curving obliquely from middle of the costa to posterior margin near the angle, violaceous-white : hindwing with the lower basal and discal area also violaceous-white : the traversing veins on both wings being pale violet-brown. Cilia violet-brown. Underside densely mottled with pur- plish violet-brown and violet-white, interspersed with black speckles, which are most prominent in a lunular marginal fascia ; a white spot at end of the cells. Body, antenne, and legs violet-brown. Expanse ;8, inch. Has. Mergui. In coll. Indian Museum, Calcutta. LOGANIA ANDERSONII, n. sp. Female. Upperside pale violet-brown: forewing with a broad lon- gitudinal medial lilacine-grey band of a somewhat triangular form, dis- posed below the cell, the exterior border of the band being scalloped : hindwing with a narrow medial discal sSimilar-coloured band. Cilia 1884.) _ Species of Asiatic Diurnal Lepidoptera. 23 alternated with white. Underside purplish lilacine-white ; both wings with a blackish zigzag cell streak, a transverse discal zigzag duplex line, and two narrow similar submarginal lines, a slender marginal line, and a waved interciliary line. Expanse 1,1, inch. Has. Mergui. In coll. Indian Museum, Calcutta. Genus Lyca#nestHes, Moore. LYCHNESTHES ORISSICA, N. Sp. Male. Smaller than ZL. lycenina and L. lycambes. Upperside of a similar purpurascent blue. Underside pale purpurascent greyish- brown. Both wings with similar, but more regularly disposed, markings. On the hindwing the subbasal costal black spot is prominent, but the subbasal black spot—so conspicuous in the above species—is absent, the entire exterior margin being uniformly marked. Expanse 5% inch. Has. Orissa. In coll. Indian Museum, Calcutta, and F. Moore. LYCHENESTHES MERGUIANA, 0. sp. Male. Upperside violet-blue: hindwing with two indistinct small anal blackish spots and a larger subanal spot. Underside dull greyish- brown ; forewing with a transverse antemedial pale-bordered band, a short band at end of the cell, and a broken discal band, two submarginal pale lunular lines: hindwing with a pale-bordered subbasal band, one at end of the cell, and a broken curved discal band ; two submarginal pale sinuous lines enclosing a small anal and a large oval subanal black spot, both surmounted by a yellow lunule and speckled with a few metallic- blue scales. Expanse 5% inch. Has. Mergui. In coll. Indian Museum, Calcutta, and F. Moore. A much smaller species than L. bengalensis. Distinguished from it, on the underside, in the forewing having the antemedial pale-bordered band; and in the hindwing in the more irregular and zigzag pale bands, and the large subanal spot. It is also distinct from L. lyceena. Genus Lycmna, Fabr. LyC@HNA CHAMANICA, N. Sp. Female. Upperside lavender-blue; extreme outer margin of fore- wing pale dusky-brown: hindwing with pale dusky-brown costal and 24 F..Moore—Deseriptions of some new Genera and [No. 1, marginal border, the latter traversed by an outer row of whitish lunules. Cilia dusky-brown, edged with white. Underside lilacine ochreous-grey : forewing with a large white-bordered black lunule at end of the cell, a discal transverse row of six spots, and a marginal row of white-bordered dark brown spots, the transverse interspace between the discal and marginal spots also dark brown: hindwing with three straightly dis- posed transverse subbasal white-bordered black spots, a lunule at end of the cell, and a curved discal interrupted row of eight spots ; a mar- ginal row of rounded dark brown spots bordered by an inner dark brown lunular line; the anal and penultimate spot is black, speckled with metallic-blue scales, and surmounted by orange-yellow. Expanse 1 inch. Has. Chaman, S. Beluchistan (April). In coll. Ind. Mus., Calcutta. This species is quite distinct from L. bracteala, Butler. LiyCHNA NADIRA, 0. Sp. Female. Upperside dark olivaceous violet-brown : hindwing with a very faint trace of paler marginal lunules. Cilia brown, edged with white. Underside pale olivaceous-ochreous : forewing with an olivaceous white-bordered large black linear spot at end of the cell, and a recurved transverse discal row of six spots, a submarginal row of small blackish dentate spots, and a marginal row of linear spots: hindwing with three subbasal olivaceous white-bordered black spots, a lunule at end of the cell, a curved discal row of eight spots, a submarginal row of small black- ish dentate spots, and a marginal row of short linear spots. Expanse 1 inch. Has. Kabul. In coll. Indian Museum, Calcutta. Quite distinct from L. fugitiva, Butler. LYCHNA BILUCHA, n. sp. Male. Upperside brilliant, glossy, opalised, lilacine cobalt-blue, the exterior margin with a very slender black border. Cilia brown, with a broad white edge. Underside pale lilacine ochreous-grey, the base of both wings slightly metallic-green: forewing with a small round white- bordered black spot in middle of the cell, a prominent streak at end of the cell, a transverse discal row of seven spots, and a marginal double row of pale brown white-bordered lunules: hindwing with a prominent white-bordered black spot in middle of the cell, one above it, a less dis- tinct spot below it, and a narrow spot on abdominal margin, a streak at end of the cell, anda discal curved interrupted row of eight spots; a ; 1884. ] Species of ease Diurnal Lepidoptera. » 25 i | ‘marginal row of white-bordered narrow black spots, each surmounted by a black-lined reddish lunule. } Expanse 1,2, inch. Has. Chaman, 8. Beluchistan (April). In coll. Ind. Mus., Calcutta. Genus CurysopHaNus, Hubner. CHRYSOPHANUS BARALACHA, 0. sp. Female. Differs from specimens of same sex of C. phlewas (vars stygianus) taken in the neighbouring country of Lahoul. Upperside : forewing golden-yellow, with a blackish quadrate spot in the middle of _ the cell, a larger spot at its end, three oblique subapical spots, and three lower discal spots, the lowest spot being the longest and curved ; from the three subapical spots some black speckles proceed to the discocellular spot ; the costal edge is very narrowly bordered with brown, and the . exterior margin has a narrow macular brown border of half the width of that of the above-mentioned species: hindwing golden greyish-brown, _ with a broad pale red outer marginal band, which is very slightly inden- ted with black at end of the veins on its outer border, and on the inner _ border by a row of indistinct blackish spots surmounted by blue-grey _ scales, above which is a discal row of five or six smaller black spots and also a black lunule at end of the cell. Underside of similar colour to that of above species: forewing with the spots as on upperside, but pale- bordered, and also a spot at base of the cell, two small spots on the costa above the discal series, and three linear spots on exterior margin above the angle, these latter spots being near the margin: hindwing with less defined red-streaked marginal band, the discal and other spots also com- paratively larger. Expanse 12 inch. Has. Baralacha Pass (16060 feet), Ladak. Taken in July 1879 by Mr. L. de Nicéville. In coll. Indian Museum, Calcutta. Genus Apunazvs, Hiibner. APHNAUS TIGRINUS, n. sp. Differs from typical A. vulcanus on the upperside of the forewing in the more prominent red bands, which, in the female, are conspicuously broader; there is also a slender marginal band, more or less indistinct in the male, but very distinct ih the female ; on the hindwing is a red mar- ginal band extending from above the anal lobe partly up the exterior margin, this band in the female being curved and reaching the subcostal 4. 26 F. Moore—Descriptions of some new Genera and [No. 1, vein. On the underside the bands are similar, but of a brighter red and with more clearly defined black borders. Expanse 1 to 12 inch. Has. Lower Bengal, Calcutta, Maunbhoom, Orissa. In coll. F. Moore and Indian Museum, Calcutta. APHNAUS PEGUANUS, 0. sp. Male. Comparatively larger than A. lohita. Upperside similarly coloured, anal area dull red, the large black lobe-spot replaced by a few interciliary black and silver scales. Underside very pale reddish- ochreous ; the bands dark red, somewhat narrower than in A. lohita: forewing with the streak at base longitudinal, narrow, and not extending above the costal vein; the short transverse broad end crossing the cellin A. lohita is here absent, the band crossing the middle of the cell is also shorter, the oblique discal and submarginal bands quite confluent at their posterior end, the inner costal band beyond the cell is short, and the next band is the longest, both being widely separated—whereas in A. lohita the inner band is the longest and the two are joined externally in the middle, the submarginal band is narrower, and the marginal band very slender: hindwing with the subbasal band composed of three well separated portions; anal lobe red, with a small interciliary black-speck- led streak ; the submarginal and marginal band narrower, the latter being interrupted in crossing the veins. Expanse 1-3, to 1,4, inch. Has. Magaree, Pegu. In coll. F. Moore. APHNEUS HIMALAYANUS, N. sp. Allied to A. lohita. Male and female much larger than typical Javanese specimens. Upperside similarly coloured ; anal area duller red. Underside pale creamy-yellow ; the bands similar, but of a darker purple- red, all comparatively broader, the marginal band conspicuously broader. Expanse ¢ 1,3, ? 1 3 to 1,5 inch. Has. Nepal (Ramsay), Darjiling (Hlliot.) In coll. F. Moore. APHN®US KHURDANUS, n. Sp. Male. Upperside dark brown; base of forewing, and hindwing dark slaty-blue ; anal lobe red, spots black. Underside dull pale pur- plish brownish-ochreous ; markings very similar to those on underside of same sex of A. trifurcatus, but comparatively narrower and more regular in outline. Expanse | to 13, inch. | Has. Khurda, Orissa; Calcutta. In coll. Ind. Museum, Calcutta. 4 1884. ] Species of Asiatic Diurnal Lepidoptera. 27 This species belongs to the lohita-group of Aphneus. On the underside the markings are extremely like those in A. trifurcatus, but the upperside of the forewings has no red patch, as in A. trifurcatus. The colour of the upperside is also of a much darker tint ; and the outline of the forewing is comparatively more triangular. APHNEUS ORISSANUS, 0. sp. Male. Forewing broader and less regularly triangular than in A. khurdanus ; hindwing also less produced anally, and the exterior mar- gin convex. Upperside dark brown; base of forewing, and hindwing, slaty-blue; anal lobe red, spots black. Underside pale ochreous-yellow ; bands purple-red, similar to those in A. peqguanus, with the marginal black black-streaked. Expanse 1,3, inch. Has. Sonakhala and Bhatpara, Orissa. In coll. Ind. Mus., Calcutta. APHNEUS CONCANUS, 2. sp. Male and female. Nearest to the Ceylonese A. lazularius. Upper- side similar. Underside pale reddish-ochreous; the bands dark purple- red, those on the forewing similar: hindwing with the subbasal band com- posed of three portions, the medial discal and submarginal bands disposed. nearer together at their costal end, the submarginal straighter, and the three more or less confluent at their anal end. Expanse 12 to 14 inch. Has. Bombay (Dr. Leith) ; Canara (Ward) ; Nilgiris (Lindsay). In coll. F. Moore. APHNAUS NIPALICUS, n. Sp. Male. Upperside dusky violet-brown, the lower basal and discal areas dark slaty-blue; anal lobe red, the black spots speckled with silvery-white scales. Underside dull sulphur-yellow, the bands of a slightly darker somewhat purpurascent yellow ; forewing with an oblique oval black ring near base of the cell, a black-lined bar across middle of the cell from the costal edge, an oblique discal band from the costal edge, broken, but not disconnected, at lower end of the cell, a short upper discal bar, and two shorter subapical bars beyond, a submarginal band and a slender broken lunular marginal line ; all but the last traversed by an extremely slight silvery line ; beneath the cell isa dusky brown fascia, and a dusky streak also is at end of the submarginal band: hindwing with a small spot at base of the cell, three transverse,subbasal oval black rings, a transverse medial band, broken at lower end, then bent upward to abdominal, margin, and ending in a small ring-spot, and outer discal 28 F. Moore—Diseriptions of some new Genera and [No. 1, upper band, a narrower submarginal band broken above anal angle and bent upward, all traversed by an extremely slight silvery line; anal lobe- spots large, black, surmounted by bright scarlet. Female. Upperside paler dusky olive-brown: forewing with sub- apical darker spot bordered on each side by red; basal area below the cell slaty-grey : hindwing with the lower basa] area slaty-grey ; anal lobe- asin male. Underside as in male. Expanse @ 13, ? 1% inch. Has. Nepal (Ramsay). Sikkim. In coll. British Museum, and Indian Museum, Calcutta. Nearest allied to A. lunulifer. APHN#US ZEBRINUS, Nn. sp. Male. Upperside dark brown, base of wings dark brownish violet- blue ; anal black spot large, broadly bordered with red. Female. Up- perside darker violet-brown, base of wings dark slaty violet-blue. Underside very pale ochreous, posterior border of forewing whitish. All the bands purplish-black, as in A. zoilus ; forewing with the extreme costal edge black, the bands also extending from the costal edge; basal streak long and joined to the black costal border, with a cross bar from its upper end, and a band crossing the middle of the cell (both of which jom the streak below the base of the cell), the oblique discal band and the transverse submarginal band are joined together at their lower end, and the two short upper discal bars are also joined together, the marginal band is broad with a very narrow interline between it and the submar- ginal band; hindwing with the upper basal streak slender, the subbasal band entire and continued to the angle of the discal band above the bright red anal area, black lobe-spots large, the discal and outer bands broad. Expanse 6 13, 2 12 inch. Has. Ceylon. In coll. British Museum. Nearest allied to the Andamanese species, A. zoilus. Distinguish- able from it by its smaller size, by the bands on the forewing all starting from the extreme costal edge, by the oblique discal band and the submar- ginal band being broadly joined at their base, and by the marginal band being broader on both wings. APHNHUS LILACINUS, n. sp. Male. Upperside brown: forewing with the basal and discal area, including the cell, pale lilacine-blue ; a blackish spot at end of the cell : hindwing with the basal and medial area pale lilacine-blue ; anal lobe 1884.) Species of ‘Asatic Diurnal Lepidoptera. 29 ochreous, with a very small silver-speckled black spot. Underside pale brownish-ochreous : forewing with two black rings in the cell, a band at end of the cell dilated beneath and extending obliquely to the sub- median, a ringlet spot beyond end of the cell, an upper discal inwardly oblique double ringlet spot and a submarginal broad chain-like band, the lower ends dusky, and each traversed by a black silvery streak : hind- wing with very indistinct traces of darker-coloured transverse subbasal, discal, and submarginal bands, which are traversed by silvery black streaks; anal spots minute, silver-speckled. The silvery streak tra- verses the middle of the markings, except on the submarginal band of both wings, where it extends along the outer border. Expanse, 1,5, inch. Has. ? Incoll. Indian Museum, Calcutta. HKUASPA, n. g. Forewing short, broad, costa arched from the base, exterior margin erect, convex, posterior margin long, straight ; first subcostal emitted at two-sixths and second at one-sixth before end of the cell, second bifid at two-thirds from its base, fourth and fifth from end of the cell; disco- cellular very slender, erect, waved ; radial from its middle; cell broad, extending to half length of the wing ; middle median from near end of the cell, lower at one-third before the end, submedian straight : hind- wing short, very broad, exterior margin convex and slightly sinuous, with a single slender tail from end of lower median; costal and subcostal veins joined together at their base, costal much arched from the junc- ture; cell broad, extending to half length of the wing; first subcostal emitted at one-fifth before end of the cell; discocellular very slender, erect ; radial from near its middle; two upper medians from end of the cell, lower at one-third before the end; submedian curved, internal short, recurved. Body short; palpi porrect, second joint long, extend- ing half beyond front of the head, pilose beneath, third joint slender, one-fifth as long as the second; legs slender ; antennez thickened at the end, tip blunt. EUASPA MILIONIA. Myrima milionia, Hewitson, [lust. D. Lep. p. 5, pl. 3, fig. 90, 80 (1869). Has. Nepal. Kangra. Genus HypoLyoana. Felder, Wien. Ent. Monats. vi, p. 293 (1862). Male. Wings short, broad: forewing arched at the base, posterior margin nearly as long as the costal. Upperside with a large glandular 30 F. Moore—Descriptions of some new Genera and [No. 1, patch of scales extending broadly across end of the cell; four subcostal branches, the first emitted at two-fifths, second at one-fourth, and third from close before end of the cell; discocellular slender, straight ; radial from its middle; cell extending to more than half length of the wing ; lower median emitted at nearly one-third and middle median from near end of the cell; submedian straight: hindwing short, somewhat pro- duced hindward, anal lobe prominent ; with a slender tail from end of lower median and another from the submedian; costal vein much arched at the base ; first subcostal emitted at one-third before end of the cell; the cell broad and extending to half length of the wing; discocellular recurved ; radial from its middle; lower median emitted at nearly one half and middle median from near end of the cell; submedian straight ; internal recurved. Palpi porrect, second joint stout, third joint very long, of nearly the same length as the second; legs slender; antennz with a gradually thickened club. Type, H. tmolus. HYPOLYCENA TMOLUS. Hypolycena tmolus, Felder, Wien. Ent. Monats. vi, p. 293 (1862). Hewits., il. D. Lep. p. 49, pl. 21, figs. 3, 6. Has. Philippines. HYPOLYCEANA SIPYLUS. Hypolycena sipylus, Feld., Reise Novara, Lep. ii, p. 242, pl. 30, figs. 15, 16. Hewits., Ill. D. Lep. pl. 22, figs. 13, 14. Myrina sipylus, Feld., Sitzb. Ak. Wiss. Wien, 1860, p. 451. Has. Amboina. HyPoLyc@NA THARRYTAS. Hypolycena tharrytas, Feld., Wien. Ent. Monats. vi, p. 294 (1862). Hyp. sisyphus, Hewits., 1. c. pl. 22, fig. 11, 12. Has. Luzon. HyPoLycRNA ERYLUS, Polyommatus erylus, Godt., Enc. Meth. ix, p. 633, (1828). Amblypodia erylus, Horsf., Catal. Lep. Mus. H. I. C. p. 111 (1829). Hypolycena erylus, Hewits., Ill. D. Lep. p. 49, pl. 21, figs. 1, 2, 4. Has. N. E. Bengal, Sikkim, Khasia Hills, Cherra Punji, Burmah, Malacca, Singapore. 1884.) . Species of Asiatic Diwrnal Lepidoptera. 31 HYPOLYCENA ANDAMANA. Hypolycena andamana, Moore, P. Z. 8. 1877, p. 589. Has. Andamans. HYPOLYCHNA THECLOIDES. Myrina thecloides, Feld., Wien, Ent. Monats. iv, p. 395 (1860). Has. Malacca, Singapore. HYPoOLYCENA ASTYLA. Hypolycena astyla, Feld., Wien.,Ent. Monats. vi, p. 294 (1862) ; Reise Novara Lep. ii, p. 248, pl. 30, figs. 17, 18, Has. Philippines. DRvUPADIA, n. g. Differs from typical Hypolycena in the more triangular form of forewing, the costa being longer and more regularly convex, the exterior margin more oblique, and the posterior margin shorter and convex to- wards the base: hindwing somewhat shorter, the costa being very con- vex in the middle, the exterior margin truncated from the middle me- dian, the male on the upperside with a prominent glandular patch of scales between the costal and subcostal veins, and with three tails, the middle one being long the others short. Second joint of palpi much longer and the third shorter and stouter. Type, D. ravindra (Myrina ravindra, Horst.). DRUPADIA BOISDUVALII, n. sp. Myrina lisias, Boisd., Spec. Gen. Lep. Pap. pl. 22, fig. 2 g (nec Fabr.). Male. Upperside: forewing purplish violet-brown, with a broad oblique transverse discal almost quadrate red band : hindwing cobalt-blue, darkest and purplish-violaceous anteriorly ; costal border and abdominal margin violet-brown ; cilia and tails edged with white. Female. Upperside: forewing somewhat paler brown, the réd band of the same width and quadrangular form asin male: hindwing pale violet-brown, the discal area somewhat red-streaked ; above the tails are four black spots surmounted by lilac scales. Underside : forewing ochreous-red, with a brighter red pale-bordered streak at base of the cell, a band across middle of the cell, another at its end, and a similar discal band which has a slightly dusky lunulated bor- der at the upper outer end, a submarginal slender black slightly sinuous line : hindwing white, the costal border and apex being slightly red, with the basal and subbasal spots entirely black, a duplex slender black streak at end of the cell, a similar one above it, a discal zigzag duplex line, and 32 F. Moore—Descriptions of some new Genera and [No. 1, a single black submarginal line; a large anal and a subanal black spot surmounted by metallic-blue scales, which also traverse the intervening subanal space. Expanse ¢ 12, ¢ 1% inch. Has. Moulmein; Mergui. In coll. F. Moore and Indian Museum, Calcutta. Drupadia lisias (Pap. lisias, Fabr.) badly figured in Donovan’s Ins. of India, pl. 40, fig. 1,—is distinct from the above. Both sexes of the type of D. lisias are in the British Museum Collection. DRUPADIA FABRICII, n. sp. Female. Upperside: forewing violet-brown, with a slightly broader and more irregular-shaped oblique medial red band than in female of typical D. lisias, the band also having its outer border scalloped : hindwing paler brown, with grey-bordered anal marginal spots. Under- side also differs from D. lisias in the apical area of forewing being suffused with a dusky tint; at the base of the cell is a small round pale- bordered spot, not an elongated triangular mark as in D. lisias, the short band crossing the middle of the cell is black, the streak at end of the cell is more distinct, the transverse discal band black-lined and black- ish internally at upper end, the submarginal line also being broader and more prominent: hindwing with the markings less prominent than in D. lisias, the basal bar shorter, the outer costal narrow streak further from the second, the first bar between the subcostals being midway be- low the two outer costals, the three subbasal spots are small and widely separated, the bar at end of the cell and the spot beneath it are pale- centred, the zigzag discal interrupted band is composed of duplex streaks, which are wide apart with the interspace white. Expanse 2 1,2, inch. Has. Mergui. In coll. Indian Museum, Calcutta. CHLIARIA, 0. g. Male. Wings small: forewing triangular; costa gently arched ; exterior margin oblique, posterior margin straight; four subcostal branches, first emitted at one-third before end of the cell and slightly touching the costal vein near its end; second and third branches at equal distances apart ; cell extending to nearly half length of the wing; discocellular extremely slender; one radial from near its middle; the middle median from near end of the cell, lower at one-third before the end; submedian nearly straight : hindwing short ; apex convex, exterior margin oblique and waved; cell short, broad; costa arched from near 1884. ] Species of Asiatic Diurnal Lepidoptera. 33 the base; first subcostal from near end of the cell; discocellular ex- tremely slender, oblique; radial from its middle; two upper medians from end of the cell, lower at nearly one-half before the end; submedian straight ; internal recurved ; a slender tail from end of lower median and another from the submedian. Palpi porrect, second joint stout, third joint very slender; antennz with a short spatular club. Type, C. othona. CHLIARIA OTHONA. Hypolycena othona, Hewits., Illust. D. Lep. p. 50, pl. 22, fig. 17, 18 (1865). Has. Darjiling. Khasia Hills. CHLIARIA ELTOLA. Hypolycena eltola, Hewits., Illust. D. Lep. Suppl. p. 14, pl. 5, fig. 37, 38 (1869). Has. Andamans. CHLIARIA KINA. Hypolycena kina, Hewits., Illust. D. Lep. Suppl. p. 18, pl. 5, fig. 32, 34 (1869). Has. Sikkim. Nepal. CHLIARIA CHANDRANA. Hypolycena chandrana, Moore, P. Z. 8, 1882, p. 249, pl. xi, fig. 2, 2a. Has. Lahul, N. W. Himalaya. CHLIARIA CACHARA. Hypolycena cachara, Moore, P. Z. 8S. 1883, p. 527, pl. xlix. fig. 6. Has. Cachar. CHLIARIA NILGIRICA. Hypolycena nilgirica, Moore, P. Z. S. 1883, p. 527, pl. xlix, fig. 8. Has. Nilgiris. SINTHUSA, n. g. Male. Wings small: forewing somewhat broad, costa arched at the base, apex pointed, exterior margin slightly oblique and convex, posterior margin convex near the base; subcostal vein five-branched, first branch emitted at nearly one-half, second at one-fourth, and third from near the end of the cell, third bifid near its end; cell extending to half length of 5) 34 F. Moore—Descriptions of some new Genera and [No. I, the wing; discocellular slender; radial from its middle; lower median at more than one-third and middle median from near end of the cell ; submedian straight : hindwing short, broad, costa arched in the middle, exterior margin with a single slender tail from end of lower median ; cell broad, triangular, extending half the wing; first subcostal at one- half before end of the cell; discocellular oblique, slender ; radial from its middle; lower median at nearly one-half and middle median from near end of the cell; submedian and internal veins recurved. Palpi porrect, second joint long, third joint short, slender, pointed ; antennz with a large thick pointed club. Type, S. nasaka. SINTHUSA NASAKA. Thecla nasaka, Horsfield, Catal. Lep. Mus. BE. I. C. p. 91 (1829). Deudoria nasaka, Hewits., Illust. D. Lep. pl. 5, fig. 45, 46. Has. Java. SINTHUSA MALIKA. Thecla malika, Horsfield, Catal. Lep. Mus. EH. I. C. p. 90 (1829). Dipsas malika, Moore, Catal. Lep. Mus. E. 1. C. I. pl. 1 a., fig. 5 (1857). Myrina malika, Hewits., Ilust. D.-Lep. pl. 15, fig. 41—43. Has. Java. Sumatra. SINTHUSA GROTEI. Hypolycena grotei, Moore, P. Z. S. 1883, p. 527, pl. 49, fig. 5. Has. N. H. Bengal (Grote). Genus Ioxatvs. Hiibner, Verz. bek. Schmett. p. 81 (1816-18). Male. Forewing short, broad; costa very much arched from the base, apex acute, exterior margin very slightly oblique, posterior margin long, slightly convex in middle, the convex edge being fringed with long hairs ; on the underside of the wing is a glandular patch of scales situat- ed immediately above the submedian vein; cell broad, extending in length to half the wing; costal vein short ; subcostal arched from the base, first branch emitted at one-half, second at one-fourth, and third immediately before end of the cell, third trifid at three-fourths from its base, fifth from end of the cell; discocellulars erect, upper shortest ; radial from near their middle ; the middle median emitted from near end of the cell, lower at one-fourth before the end; submedian straight: 1884.) Species of Asiatic Diurnal Lepidoptera. 35 hindwing short, lengthened hindward; costa very convex, apex almost angular, exterior margin very oblique and sinuous, lobate at anal angle, furnished with two short slender tails; on the upperside is a subcostal glandular patch of scales ; costal and subcostal veins joined together for ashort distance at their base, widely separated beyond, costal much arched from the basal juncture; cell broad, triangular ; two subcostal branches, first emitted at one-third before end of the cell; discocellulars very oblique ; radial from near their middle ; two upper medians from end of the cell, lower at one-third before the end; median straight ; internal short. Body moderate; palpi ascending, second joint long, ascending above level of the eyes, third joint half its length, slender; legs slender ; antenne slender, gradually thickened to end, tip pointed. Type, I. helius (helius, Fabr.; Hewits., Ill. D. L. Suppl. pl. 4, f. 31.) The typical species of Iolaws are African. The characters of the genus are here given for comparison with its Asiatic allies. CopHANTA, n. g. Forewing broad, costa arched, exterior margin slightly convex, posterior margin nearly straight ; cell broad, extending to half length of the wing, costal vein extending to half the margin; first subcos- tal emitted at two-fifths and second at one-fourth before end of the cell, third bifid at nearly two-thirds from the base; discocellular slender, slightly bent outward in the middle; the radial from its angle; lower median at one-third and middle median from close before end of the cell; submedian straight: hindwing broad, costa abruptly arched at the base, apex convex, exterior margin oblique and sinuous from middle median, anal angle lobed, with a slender tail from lower median and another from submedian ; costal and subcostal joined together for a short distance at the base, the costal much arched from above the junc- ture, and extending to the apex; first subcostal emitted at one-fifth be- fore end of the cell; discocellular outwardly oblique and bent outward at the middle ; the radial from its angle; cell broad, extending to nearly half the wing ; lower median at one-third and middle median from im- mediately before end of the cell; submedian straight ; internal recurved. Body short, thick ; palpi porrect, second joint long, extending half length beyond the eyes, third joint slender, slightly fusiform, nearly half length of the second ; antennez short, stout, with a gradually thickened club ; legs short. Type, C. illurgis. 36 F. Moore—Descriptions of some new Clenera and [No. 1, CoPHANTA ILLURGIS. Iolaus illurgis, Hewitson, Illust. D. Lep. Suppl. p. 10, pl. 4, fig. 37, 38 (1869). Has. Darjiling. CoPHANTA MACULATA. Iolaus maculatus, Hewits., Illust. D. Lep. p. 47, pl. 21, fig. 29, 30 (1865). Has. Silhet. Darjeeling. DACALANA, n. g. Male. Forewing comparatively more triangular than in typical Tolaus (I. helius), the exterior margin being somewhat oblique, and the posterior margin shorter; venation similar; on the upperside of the typical species, between the median and submedian veins, is a tuft of fine hairs covering a small glandular-scaled spot, and on the underside there is also a tuft of hairs on the middle of the posterior margin: hindwing comparatively broader, being less produced hindward, the apex more convex, and the glandular subcostal spot less prominent. Type, D. vidura (Amblyp. vidura). DACALANA VIDURA. Amblypodia vidura, Horsf., Catal. Lep. Mus. E. I. C. p. 113, pl. 1, fig. 6, 6a. g; (1829). Harn. Java. Borneo. DACALANA BURMANA, 0. Sp. From typical Javan D. vidura, this differs in the darker blue of the upperside. The colour of the underside is also brighter and of an ochreous-brown tint, the transverse white band is somewhat broader, the submarginal black line composed of short curved portions between the veins, and the whole series forms a more curved line in crossing each wing ; the black subanal and lobe-spot is slightly smaller, and the former is but very slightly surmounted with red. Expanse ¢ 1; inch. Has. Moulmein. In coll. British Museum. DACALANA COTYs. Iolaus cotys, Hewitson, Ilust. D. Lep. p. 48, pl. 19, fig. 19, 20 (1865). Has. Nepal. Darjiling. (1884.4 Species of Asiatic Diwrnal Lepidoptera. 37 Genus Pratapa, Moore. PRATAPA BHOTEA, 0. sp. Female. Upperside purpurascent greyish-blue: forewing with the anterior margin from the costal vein, the apex broadly, and the exterior margin violet-brown ; cilia grey: hindwing with a marginal row of nar- row violet-black spots ending in a red anal lobe-spot; a slender black marginal line; cilia greyish-white; the two tails black with white cilia. Underside glossy purpurascent greyish-white: forewing with an indistinct darker bluish-grey streak at end of the cell, and two slender lunular fasciz along exterior margin ; a transverse discal slender promi- nent black broken sinuous line: hindwing with a similar cell streak and outer marginal fascie, the latter darkest at anal end; a jet black anal lobe-spot, on which are a few scarlet scales and some turquoise-blue scales along its inner border; a transverse discal zigzag slender black broken line ending upward above the anal lobe. Expanse 13 inch. Has. Sikkim. In coll. Indian Museum, Calcutta. REMELANA, 0. g. Male. Forewing less triangular than in Tajuria (T. longinus, Fabr.), the costal margin more abruptly arched at the base, exterior margin slightly convex, posterior angle rounded: hindwing broader and _ less produced hindward ; costa less arched at the base, very convex external- ly, with a slender tail from end of lower median and another from the submedian, abdominal margin short. Palpi shorter, second joint stouter, and third joint longer; antenne shorter, tip shorter and more regularly clavate. Venation similar. Type, ft. jangala. REMELANA JANGALA. Amblypodia jangala, Horsfield, Catal. Lep. Mus. E. 1.0. p. 113 (1829), 9; Moore, ibid. p. 40, pl. la, f. 11, ¢. Has. Java. N. H. Bengal. REMELANA TRAVANA. Myrina travana, Hewitson, Ilust. D. Lep. p. 38, pl. 17, f. 59-60 (1865) 3. Has. Sumatra. Singapore. Borneo. 38 F. Moore—Descriptions of some new Genera and [No. 1, . APPORASA, 0. g. From Thaduka this differs in the forewing having the exterior margin biangulated and produced outward below the apex. In the hindwing the costa is longer, arched at the base, and produced to an upward angle at the apex; the exterior margin is deeply scalloped ; it also has three shorter tails. Palpi long, porrect, second joint extending two-thirds beyond the eyes, third joint also long and slender, being half the length of second ; antennze stouter and blunt at tip. APPORASA ATKINSONI. Amblypodia atkimsom, Hewits., Catal. Lyc, Brit. Mus. p. 3. pl. 8, fig. 92, 93 (1862). Has. Moulmein. SATADRA, n. g. Forewing comparatively longer and narrower than in typical Pan- chala, the costa abruptly arched at the base, exterior margin oblique : hindwing slightly but regularly arched along the costa, apex very con- vex, exterior margin oblique, with a slender tail at end of lower median vein and a point at end of both the middle median and submedian. Venation similar to that of Panchala. Type, S. atraz. SATADRA ALBA. Amblypodia alea, Hewits., Catal. Lyc. B. M. p. 12, pl. 7, fig. 79, 81 (1862). Has. India. SATADRA SELTA. Amblypodia selta, Hewits., Ill. D. Lep. p. 14. pl. 8a, £. 36, 37 (1869). Has. Moulmein. SATADRA AGABA, Amblypodia agaba, Hewits., Catal. Lyc. B. M. p. 8, pl. 4, f. 39, 40 (1862). Has. India. In the Hewitson Cabinet this species is placed under S. alea. SATADRA BUPOLA. Amblypodia bupola, Hewits., Ill. D. Lep. ii. Suppl. p. 21, pl. 8, fig. 44, 45 (1878). Has. Nepal. Daryjiling. iv ‘ f 1884.) | Species of Astatic Diurnal Lepidoptera. 39 SATADRA BAZALUS. Amblypodia bazalus, Hewits., Catal. Lyc. B. M. pl. 4, fig. 37, 38 (1862) g. Has. Nepal. SATADRA ATRAX. Amblypodia atrar, Hewits., Catal. Lyc. B. M. p. 13, pl. 7, fig. 80, 82 (1862). Has. Nepal. SATADRA ANTHELUS. Amblypodia anthelus, Doubleday and Hewits., Gen. D. L. pl. 74, f. 6 (1852). Hewits., Catal. Lyc. B. M. pl. 3, f. 23. 24. Has. Moulmein. SATADRA CANARAICA, 0. sp. Allied to S. alea (Amblypodia alea, Hewits). Male and female. Upperside of a more purplish violet-blue than in SV. alea, the marginal black border comparatively narrower in the male. Underside of a darker purplish violet-brown: forewing with the basal spots darker, the two cell-spots very small and round, the discocellular spot and the two below the cell narrower, the transverse discal band regular and not broken on the upper median vein, the submarginal and marginal lunules obsoles- cent: hindwing with the basal and subbasal spots darker and very small, the discal zigzag band narrower and less distinct, the submarginal and marginal lunules obsolescent; anal angle less speckled with metallic- green scales, the anal black spot only present. Expanse ¢ 13, ? 14 inch. Has. Canara, S. India (Ward). In coll. F. Moore. In S. alea the underside is uniformly purplish-brown, the markings all of a regular colour and distinctly lined with pale purplish-white. SATADRA CHOLA, N. sp. Closely allied to S. areste (Amblypodia areste, Hewits.). Male. Upperside of a comparatively darker purplish blue, the marginal black borders being one half less the width. Female. Upperside also with the blue area extending comparatively more over the disc. Underside : fore- wing more dusky olive-brown in colour, with much narrower whitish cell-streak, quadrate spot beneath it, and transverse discal band, the outer band being more defined: hindwing with similarly disposed markings except that the subbasal band is very broad and entire (not 40 F. Moore—Descriptiohs of some new Genera and [No. 1, macular as in 8. areste), and the markings are all of a dark somewhat aenescent-brown, with pale pinkish-white borders and the interspaces pale pinkish violet colour (not grey as in S. areste) ; at the anal angle is a marginal black spot and another between the middle and lower median veins, both spots and the intervening marginal space speckled with me- tallic-green scales. Expanse $ @ 1,8; inch. Has. Sikkim. In coll. Indian Museum, Calcutta, and F. Moore. SATADRA LAZULA, 0. sp. Male. Upperside of both wings entirely ultramarine-blue ; the ex- treme costal edge of forewing, the costal and abdominal borders of hind- wing, and the cilia being black. Female. Dark violet-brown, the forewing with ultramarine-blue within the cell and obliquely below on the disc, and narrowly on middle of the hindwing from base of the cell. Underside dark purple-brown : forewing with similarly disposed but broader markings than those in S. chola, the two outer bands purplish-violet: hindwing dark purple- brown, with similar markings to those in 8. chola, the discal bands con- tinuous, the interspaces brighter pink, the anal marginal spots small and more numerously green-speckled. Expanse 1,8, inch. Has. Sikkim. In coll. Indian Museum, Calcutta, and F. Moore. SATADRA PATUNA, 0. sp. Female. Smaller than §. lazula. Upperside dark violet-brown, the basal and discal areas purplish-blue, paler than in S. lazula, but disposed as in female of that species. Underside purplish-brown : fore- wing with similarly disposed cell, streak, discal band, and lower quadrate patches, but of a pale ochreous colour: hindwing with the basal area broadly and entirely dark bright purple-brown (more like that of typi- cal S. apidanus), which merges into a transverse broad pale purplish- ochreous inner discal fascia, and again into a dark purplish-brown outer discal fascia, the outer border of the wing being broadly pale purplish- brown; across the disc are traced two series of indistinct brown-lined. marks, which are similarly disposed to, but are less continuous than, those in 8. lazula; an indistinct brown marginal lunular line, but no metallic speckles at anal angle. Expanse 1} inch. Has. Nepal (General Ramsay). In coll. F. Moore. ——-1884.] Species of Asiatic Diurnal Lepidoptera. SATADRA CHCA. Amblypodia ceca, Hewits., Ill. D. Lep. p. 14, pl. 4, fig. 28 (1863). Has. Borneo (Sarawak). SATADRA ARESTE. Amblypodia areste, Hewits. Catal. Lyc. B. M. pl. 5. f£. 48, 44 (1862). Has. Darjiling. SATADRA FULGIDA. Amblypodia fulgida, Hewits., Ill. D. Lep. p. 11, pl. 5, fig. 31 (1863). Has. [? Philippines]. N. India. SATADRA CHINENSIS. Arhopala chinensis, Feld., Reise Novara Lep. ii, p. 231, pl. 29, f. 10 (1865). Has. China. SATADRA DIARDI. Amblypodia diardi, Hewits., Catal. Lyc. B. M. p. 9, pl. 5, f. 41, 42, (1862). Has. Penang. Singapore. SATADRA APIDANUS. Papilio apidanus, Cram., Pap. Exot. ii. pl. 187. f. F. G. (1779). Amblypodia apidanus, Horsf., Catal. Lep. Mus. H. I. C. p. 100 (1829). Has. Java. Sumatra. Borneo. SATADRA ABSENS. Amblypodia absens, Hewits., Catal. Lyc. B. M. p. 9, pl. 5, f. 51, 52 (1862). Has. Daryjiling. SATADRA ZETA. Amblypodia zeta, Moore, P. Z. 8. 1877, p. 590, pl. 58, f. 6. Has. Andamans. ACESINA, n. g. Al Forewing with the costa less arched than in Panchala, apex less Type, A. paraganesa. 6 pointed, exterior margin more oblique, and waved ; fourth subcostal vein emitted further from end of the third: hindwing not so broad or quadrate in shape, the costa but slightly arched from the base, exterior margin more oblique and regularly convex, with a slender tail one-fourth of an an inch long from end of lower median vein ; abdominal margin shorter. Antennal club somewhat shorter. 42 F. Moore—Descriptions of some new Genera and [No. I, ACESINA PARAGANESA. Amblypodia paraganesa, De Nicéville, Journ. Asiat. Soc. Bengal, 1882, p. 63. Panchala paraganesa, Moore, P. Z. 8. 1883, p. 530. Amblypodia ganesa, Hewits., Catal. Lyc. B. M. pl. 7, f. 72 (1862). Has. Nepal. DaRASANa, n. g. Forewing short, broad, triangular ; apex acute, exterior margin very slightly oblique, posterior angle somewhat rounded: hindwing short, broad ; costa arched towards the base, exterior margin very convex; no tail. Antenne slender. Type, D. perimuta. DARASANA PERIMUTA. Amblypodia perimuta, Moore, Catal. Lep. Mus. E. I. C. 1, p. 42 (1857). Hewits. Catal. Lyc. B. M. p. 12, pl. 6, fig. 65, 66. Has. Khasia Hills. Magaree, Pegu. DARASANA NEWARA, 0. sp. Upperside violet-brown: forewing with the basal and discal area purplish violet-blue, which extends also above the cell to near the costal edge, the outer brown border being about one-tenth of an inch in width: hindwing with the basal area purplish violet-blue, the outer border being two-tenths of an inch in width. Underside pale-brown ; with faint traces of pale-bordered marks within and beneath the cell, at its end, and a more distinct narrow macular discal and submarginal lunular band: hindwing with four indistinct pale-bordered darker brown basal spots, a similar subbasal series, a discal broken band, and marginal double lunular band. Expanse 1,2; inch. Has. Nepal (Genl. Ramsay). In Coll. F. Moore. Genus Naratuura, Moore. NARATHURA ROONA, 0. sp. Closely allied to, but smaller than N. aroa (Amblypodia aroa, Hewit- son, Ill. D. Lep. p. 13, pl. 2, f. 12), from Sumatra. Female. Upperside dark violet-brown, costal edge and cilia paler: forewing with the basal and discal area, and the hindwing with the basal and medial discal area, violet-blue. Underside of a similar tint of brown to that in N. aroa, mark- ings also similarly disposed, but with darker centres; on the forewing 1884. | Species of Asiatic Diurnal Lepidoptera. 4.3 the cell-spots are smaller and oval in shape, and the discal band broader ; on the hindwing the basal spots are more rounded, the discal band more conspicuous and less zigzag in shape, and the submarginal and marginal lunular line more distinctly formed ; at the anal angle is a black spot and another between the median veins, the spots and intervening space being speckled with metallic-green scales. Expanse 1,8; inch. Has. Andaman Isles. In coll. Indian Museum, Calcutta, and British Museum (Hewitson Cabinet). Genus AmsBiypopiA, Horsfield. AMBLYPODIA ANDERSONII, n. sp. Male. Smaller than A. taooana. Upperside of a similar tint of ultramarine-blue ; both wings with a much narrower black marginal border. Underside much darker-coloured, but similarly marked. Expanse 14 inch. Has. Sampu, Mergui (Dr. Anderson). In coll. Ind. Mus., Calcutta. Family PAPILIONIDAL. Subfamily Pisrina. Genus CatropHaca, Hiibner. CATOPHAGA WARDII, n. sp. Allied to the South Indian and Ceylonese C. neombo. Male and female of much larger size. | Male. Upperside olivaceous-white: forewing with a broad black apical band extending from middle of the costa to near the posterior angle, the band traversed by a curved subapical row of five small white spots, the inner border of the band excavated below the costa to below the second upper spot, then bulged inward to the disc in front of the two lower spots, concave below the middle median to lower median, below which the end of the band is imperfect and terminates on the submedian ; base of wing broadly grey and sparsely speckled with minute black scales on base of the costa: hindwing with a marginal series of broad black confluent dentate spots, which decrease in width from the costa. Underside : forewing olivaceous-white, apex pale yellow, with a curved black subapical band similar to the inner portion on the upperside : hind- wing pale yellow throughout. Female. Upperside of a darker tint of olivaceous-white than in male; forewing with a broader black apical band, which is traversed by Ad F. Moore—Deseriptions of some new Genera and [No. I, three subapical white spots, the inner border of the band being less exca- vated below the costa, the excavated space being shorter and angular on the middle median, more deeply concave beneath it, and the end entirely black to the submedian vein: hindwing with a broader continuous black band, the inner border of which is acutely dentated. Underside: fore- wing with the basal area tinged with yellow, the discal area olivaceous- white, and the apex glossy olivaceous-white ; a broad curved subapical black band corresponding to the inner portion on the upperside : hind- wing entirely pale glossy olivaceous-white. Expanse ¢, ? 22 inches. Has. Coonoor, Nilgiris, S. India (Ward and Lindsay). In coll. Indian Museum, Calcutta, and F’. Moore. CATOPHAGA ROEPSTORFFII, 0. sp. Male. Upperside white: forewing slightly grey and sparsely black- scaled along base of costal border ; a black-speckled spot between upper and middle median veins. Hindwing immaculate. Underside: fore- wing white, apex very pale yellow; the black-speckled spot as above: hindwing very pale yellow. Expanse 22 inches. Has. Nicobar Isles. In coll. Indian Museum, Calcutta. Near to C. paulina. Male. Differs from the same sex of that spe- cies in the entire absence of the blackish apical margin on the forewing, and in the presence of the discal spot. Genus Ix1as, Hiibner. IXIAS GANDUCA, n. sp. Male and female. Upperside deep sulphur-yellow: male: forewing with the apex brownish black traversed by a moderately broad orange- red subapical band, the inner border of the band being very slightly edged with black: hindwing with a very slender black-speckled marginal band. Female : forewing with a narrower and more irregular-bordered sub- apical band, which is slightly tinged with orange-yellow, the inner border of the band is broadly black across end of the cell, and from the upper median to the indentation of the lower portion of the band the border consists of a very slender black-speckled line, the lower portion of the band is indented with black, the next upper interspace has a medial black spot, and the third upper interspace is broken by a large black spot : hindwing with a broader dentate-bordered black marginal band. Under- 1884. ] Species of Asiatic Diurnal Lepidoptera. Ad side of both sexes ochreous-yellow, palest on base of the forewing ; both wings with sparsely disposed slender brown strigew: forewing with a blackish spot at end of the cell, a transverse discal row of purple-brown- speckled spots with white centres; hindwing with a similar white-centred purple-brown-speckled costal spot and row of discal spots, the second and third upper spots being the largest : a brown dot also at end of the cell. Expanse ¢ 2, 2 24 inches. Has. Calcutta (February). In coll. Indian Museum, Calcutta. Nearest to, but distinct from, I. moulmeinensis. The male differs from it above in the comparatively narrower orange-red band and its less black inner border. The female also is quite different from the same sex of that species. © Genus Ipmais, Boisd. IDMAIS SURYA, 0. sp. Nearest to I. ortens. Male larger, upperside much brighter-colour- ed, the black apical band broader, and is traversed by three spots only, which are comparatively shorter ; the marginal spots are more prominent, the black inner border terminating on the upper median as in I. oriens ; below the three subapical spots are two black spots. Cell-spot on fore- wing three times the size of that in JI. ortens on both the upper and underside : hindwing with six marginal black spots, larger than in JI. oriens. Underside much brighter-coloured than in I. oriens; base of both wings deep yellow, the outer borders broadly suffused with orange- red, the discal macular band similar but much less prominent on the hindwing. Expanse 1¢ inch. Has. Sonakhala, Orissa. In coll. Indian Museum, Calcutta. Genus Mancipium, Hiibner. MANCIPIUM NAGANUM, n. sp. Male. Upperside pale yellowish-white ; forewing with the base of the costal border sparsely black-speckled ; a black band at the apex, the inner border of the band being curved, slightly irregular, and termina- ting at the middle median vein; a small black discal spot between the upper and middle medians, and a slight black-speckled spot at lower end of the cell. Underside: forewing white, with the apex pale yellow, the discal and discocellular spot as on upperside : hindwing yellow. Expanse 2 inches. Has. Naga Hills, Assam. In coll. Indian Museum, Calcutta. 46 F. Moore—Descriptions of some new Genera and [No. }, Genus Appras, Hiibner. APPIAS AMBOIDES, n. sp. Male. Upperside white: forewing with a narrow apical black band. Underside : forewing white, the costal border, and apex corresponding to tle band on upperside, pale brownish-ochreous: hindwing entirely pale brownish-ochreous, with a slight indistinct dusky fascia extending from the base along the subcostal and median vein. Expanse 12 inch. Has. Silhet. Dihung, Assam. In coll. Indian Museum, Calcutta, and F. Moore. Genus Hiposcritia, Hiibner. HIPOSCRITIA IMBECILIS, n. sp. Male. Upperside white : forewing with a black-speckled apical band, which is traversed by four subapical white spots. Underside: forewing white, with the apex ochreous-white and slightly speckled with ochreous- brown scales: hindwing ochreous-white, sparsely speckled with ochreous- brown scales with slight traces of their clustering on the anterior margin near end of the costal and subcostal veins and across the disc in an indis- tinct zigzag fascia ; a small blackish spot at end of the cell. Expanse 12 to 2 inches. Has. Silhet; Assam. In coll. Indian Museum, Calcutta, and F. Moore. Allied both to H. indra and to H. mahana. Distinguished from the latter by its smaller size. Forewing with paler and less defined black- ish apical band. No subapical curved black fascia on the underside. Subfamily PapiLionina. Genus Papinio, Linn. PAPILIO LADAKENSIS, n. sp. Male. Distinguished from the N. W. Himalayan P. asiaticus by the absence of the elongated tail on the hindwing, which in this form is reduced to a short point but little more acute than the anal angle. The forewing 18 comparatively narrower, and the hindwing is less convex and with less acutely sinuous exterior margin. On the upperside the yellow is also of a paler tint: forewing numerously covered with yellow scales between all the markings, the cell bands are shorter transversely and broader, and the inner cell-band is regularly quadrate ; the discal bands 1884. ] Species of Asiatic Diurnal Lepidoptera. AT also comparatively narrower and with more slender intervening black veins ; the marginal row of spots is broader, and the intervening trans- verse discal area is narrower: hindwing with the outer border of the yellow basal area excavated between the veins, the marginal spots shorter and somewhat broader, the anal lobe-spot also smaller and broader® Expanse 3} inches. Has. Tarhsam, Ladak. In coll. Indian Museum, Calcutta. PAPILIO SIKKIMENSIS, n. sp. Differs from N. W. Himalayan and Nepalese specimens of P. asiati- cus in the very much darker black colour of the upperside ; and in the forewing having the yellow cell-bands quadrate in form, the discal band composed of smaller and shorter portions, and the area intervening be- tween the band and the marginal spots broader. On the hindwing, the veins are broadly black-lined, the abdominal border also black and leay- ing but a small subanal lunule; the discal margin of the yellow area has a more regularly scalloped edge, and there is also a broader discal area intervening between it and the marginal spots; the crimson anal lobe-spot is smaller, narrower, and has a lower retort-like black spot. Expanse 2¢ to 33 inches. Has. Sikkim (Hlwes). Family HESPERIIDZ. CUPITHA, n. g. Male. Forewing elongated, triangular, costa arched at the base, exterior margin oblique, posterior margin convex towards the base ; first subcostal emitted at nearly one-half before end of the cell, the branches at equal distance apart; cell extending to nearly two-thirds length of the wing; discocellular almost erect, slightly bent close to upper end and below the middle ; upper radial from the angle near subcostal, lower radial from the angle below the middle ; the middle median at one-sixth, and lower median at four-sixths before end of the cell, submedian undu- lated ; on the underside of the forewing is a short, broad, nacreous patch on the middle of posterior margin, across which the submedian is lined with rough scales, and from near the base of the margin projects a broad. pencil of long rigid hairs: hindwing short, costa very much arched from the base, apex rounded ; costal vein extending to near apex, forked at its base ; subcostal bent upward and slightly joined to costal close to the base, subcostal two-branched, first branch from close to end of the cell ; discocellular very slender, slightly oblique and concave ; cell extending 48 F. Moore—Descriptions of some new Genera and [No. 1, to nearly half the wing, of equal width throughout; middle median from near end of the cell, lower at more than one-half before the end, the portion from the middle median to lower median distorted and extending beneath a drum-like glandular sac, which extends upward in a circular form within the cell from base of lower median, the sac, or drum, as seen from the upperside, is flat, with a well-defined circular rim, and on the underside, it stands out from the surface in a corrugated circular form ; no radial present ; submedian straight ; internal vein curved. Thorax stout; antennz with a slender club. Type, O. tympanifera. CUPITHA PURREEA. Pamphila Purreea, Moore, P. Z. S. 1877, p. 564, pl. 58, fig. 10, 9. Wood- Mason, Journ. Asiat. Soc. Bengal, 1881, p. 261. Has. South Andaman. CUPITHA TYMPANIFERA, 0. sp. Male. Upperside dark violet-brown ; forewing witha broad gam- boge-yellow basal costal band, and an oblique discal sinuous-bordered band extending upward from near base of the posterior margin to near the apex: hindwing with a broad transverse discal yellow band extend- ing from near the abdominal margin to near the apex and thence upward along the costal border. Cilia yellow. Body brown; abdomen with yellow bands. Underside deep gamboge-yellow: forewing with a short ochreous-brown streak extending longitudinally from the base to end of the cell, and a broad patch at the posterior angle: hindwing with a similarly coloured speckled patch near anal angle ascending upward from end of submedian vein. Palpi and legs yellow, antenne annulated with yellow. Expanse ¢ 12. Has. Magaree, Pegu. In coll. F. Moore. This is a comparatively larger insect than C. purreea; the bands on the forewing are broader and with more irregular borders, the bands on the hindwing are also broader. Genus PiesionneuRA, Felder. PLESIONEURA MUNDA, 0. Sp. Male and female. Upperside olive-brown: forewing with an ob- lique transverse discal semidiaphanous white band, similar to, but more compact than that in P. leucocera, the apex-spot starting from above the costal vein, the two lower large spots, the small one beneath, as well as that outwardly between them, are not separated from each other, the 1884.) “Species of Asiatic Diurnal Lepidoptera. 49 second lower spot between the median and submedian only being apart from the rest; three subapical conjoined white spots and two minute lower dots; cilia very faintly alternated brownish-white: hindwing uniformly olive-brown: cilia deeply alternated with white. Underside paler than above: forewing marked the same: hindwing numerously speckled with olive-green scales towards abdominal margin; an olive- green-speckled lunule at end of the cell. Expanse 1? inch. Has. Simla (Lang). In coll. F. Moore. Genus Svuastus, Moore. SUASTUS ADITUS, n. sp. — Male. Upperside dark violet-brown: forewing with two small qua- drate yellow spots at end of the cell, a larger spot immediately beneath end of the cell between the middle and lower medians, and a small spot between the base of upper and middle medians; between the lower median and submedian is a very slight trace of an opaque yellowish streak ; cilia edged with grey. Underside paler brown: forewing with the spots as above, and a whitish discal patch below them: hindwing speckled with olive-grey scales, which are most thickly disposed along the abdominal border and form a distinct line along the submedian vein ; two dark brown discal spots, one being situated between the middle and lower medians, the other between the latter and submedian. Body, pal- pi, and legs beneath olivaceous-grey. Expanse 1,2, inch. Has. Andaman Isles. In coll. Indian Museum, Calcutta. Allied to S. sala (Hesperia sala, Hewits.). SUASTUS MOLLERII, n. sp. Male. Upperside very dark olive-brown: forewing with three small narrow white semidiaphanous subapical spots, a larger narrow spot at lower end of the cell, a still larger spot below end of the cell, and a small very slender spot between base of upper and middle medians; a small yellowish opaque spot also above middle of the submedian: hindwing with the abdominal border broadly paler olive-brown, Cilia cinereous- white. Underside: forewing dusky-black, the costal border and apical area pale olive-brown ; spotted as above: hindwing very pale olive-brown, with the interspace between submedian and internal veins white. Palpi beneath, and legs, and abdomen beneath, white. Expanse 13 inch. Has. Sikkim (Otto Moller). In coll. Indian Museum, Calcutta, 7 50 F. Moore—Descriptions of some new Genera and [No. 1, Genus Satarupa, Moore. SATARUPA PHISARA 0. sp. Male. Upperside dark vinous-brown : forewing with two, sometimes three or four, minute semidiaphanous yellowish white subapical spots, a small spot at lower end of the eell, a large quadrate spot below end of the cell, and a small spot also between the base of upper and middle medians ; a very indistinct greyish-brown-speckled submarginal lunular fascia and a similar short fascia below the quadrate discal spot: hind- wing with a transverse subbasal pale yellowish band, and a curved sub- marginal indistinct greyish-brown-speckled lunular fascia, which gives the discal area a macular appearance. Female: forewing marked as in male, the short fascia below the discal spot more distinct: hindwing with the transverse band somewhat broader, the discal area between it and the submarginal lunular fascia more distinctly macular, being tra- versed by pale veins. Underside as above, the markings more promi- nent. Abdomen with slender white narrow bands; front of head and base of palpi, and pectus, orange-yellow, tip-of palpi black. Expanse ¢& 1,5, 2 1,8 inch. Has. Khasia Hills. In coll. Indian’ Museum, Calcutta, and F. Moore. Alhed to S. bhagava and to 8. sambara. SATARUPA NARADA, 0. sp. Upperside purpurascent violet-brown : forewing with three small upper and two lower subapical semidiaphanous white spots, a small erect oval spot at lower end of the cell, a slightly larger quadrate spot on the disc between upper and middle medians, and a broad band formed of three quadrate spots increasing in width from end of cell to posterior margin : hindwing with a broad white transverse medial band, the outer border with an ill-defined upper spot. Cilia edged with white. Underside marked as above; the hindwing with the band showing a more defined macular outer border and a well separated upper spot. Expanse 1,4, inch. Has. Darjiling, Sikkim. In coll. Indian Museum, Calcutta, and F. Moore. Nearest allied to S. bhagava, but quite distinct. 1884.) Species of Asiatic Diurnal Lepidoptera. 51 Genus TaciapEs, Hubner. TAGIADES KHASIANA, 0. Sp. Male. Nearest to 7. ravi. Of larger size: forewing comparatively more pointed at the apex: hindwing also broader, and with a more an- gular apex. Upperside of a paler olivaceous-brown, the dusky markings less distinct on both wings, the apical and discal spots smaller. Female upperside also paler than in 7. ravi, the apical spots on forewing some- what smaller, the cell spots similar, the two discal spots somewhat larger. Underside : forewing with the spots as above: hindwing more intensely whitish grey, the discal black spots much smaller and less de- fined. Expanse & 2, 9 2,1, inches. : Has. Khasia Hills; Shillong; Assam. In coll. Indian Museum, Calcutta, and F. Moore. LOBOCLA, n. g. Male. Forewing triangular, the edge of the costal margin slightly folded over on to the upperside from near the base toend of the costal vein ;* the costal vein extending to three-fifths the margin ; subcostal five-branched, first branch emitted at one-third before end of cell, second and third at equal distances from the first, fourth and fifth from end of _ the cell: discocellular bent outward near upper end and inwardly ob- lique hindward ; upper radial from the angle near subcostal, lower radial from the middle; cell long, extending beyond two-thirds the wing; three medians, lower at three-fourths and middle median at about one- fourth before end of the cell; submedian straight: hindwing short, broad, apex rounded, exterior margin slightly produced and angular at end of submedian vein; costal vein extending to the apex ; subcostal touching the costal close to the base, two-branched, first branch at one- fourth before end of the cell; discocellular very slender, almost erect ; the radial from its middle ; cell broad, extending to half the wing; two upper medians from end of the cell, lower at about one-third before the end; submedian and internal vein nearly straight. Body short, stout, thorax hairy; palpi broad, thickly clothed, apical joint short, thick ; antenne with a long slender-pointed tip ; femora and tibie short, stout, slightly pilose, middle tibis with two and hind with four spurs, tarsi long. Type, L. liliana. * The species of Erynnis ((H. alcee, etc.) have a similar fold on the costal mar- gin of the forewing. 52 F. Moore—Deseriptions of some new Genera, &c. [No. 1, 1884.] LOBOCLA LILIANA. Plesioneura liliana, Atkinson, P. Z. 8. 1871, p. 216, pl. xxii, fig. 2. Has. Yunan. LOBOCLA CASYAPA, 0. sp. Differs from L. liana in its smaller size. Upperside somewhat paler and of an olive-brown tint, sparsely speckled with olive-grey scales: forewing with the transverse semidiaphanous yellow band one-third less in width, the portions being distinctly defined by the traversing brown veins, the subapical spots also much smaller. Underside much paler : forewing numerously speckled with greyish-ochreous scales at the apex, the band and apical spots as above: hindwing with similarly disposed markings, but all composed of more numerous greyish-ochreous scales, these scales being whitish m L. liliana. Expanse 1,8 inch. Haz. Masuri (Zang). Cashmere (Reed). In coll. Indian Museum, Calcutta, and F. Moore. Plate II. 257TH JUNE 1888. — Lithographed at the Survey of India Offices, Calcutta, September 1884. a Si aoane ee nl tn ar a ey i oO I i“ ee en apie 7 eae ey ee : Shi HAUL wees.) ‘ ¢ sts. bet = t J. ELIOT. Jour As. Soc, Bengal, 1884, Vol. LIII, Pt. II. Plate III. 27TH JUNE 1883. Lithographed at the Survey of India Offices, Calcutta, September 1884. — ee + J. ELIOT, Jour. As. Soc. Bengal, 1884, Vol. LIII, Pt. IT. Plate IV. 29TH JUNE 1883. Lithographed at the Survey of India Offices, Calcutta, September 1884, ae 5 fe ee er og Se i, se a he RE RNR Ay ne a ag Sl eA mem & —- i" - ee. A sree » a eet i - n aan rere: * pat Sai ete es Ss a 6 a oe asl Hey 5 os - a f ai “BeBe AUUL 7 f . - . i Le 4 i; - > ie i. ~—e= = - _ — ~ a x - 0 r rn , « Z d af-aoe . mal Soy > Pe I. a * Dd ©, eg f a > . 4 .a% a I an ioe St any SR : ET AB a vo on) war ha Peo * < Cle nl FP ye 4 ~ Ce “: i a ° - ae es Tis wy y. ‘ oe ° , . > a } oe ke J. ELIOT, Jour. As. Soc, Bengal, 1884, Vol. LIII, Pt. II. Plate V. Ist JULY 1888. 2ND JULY 1883. iu ee eM a i ee Lithographed at the Survey of India Offices, Calcutta, Septernber 1884, ka aoe ; Siskel He ae or = * Tey > ahs ne reaek, AUT wet al, J. ELIOT, Joup. As. Soc. Bengal, 1884, Vol. LIII, Pt. II. Plate VI. 3rD JULY 1883. Lithogravhed at the Survey of India Offices, Calcutta, September 1884, , ts a ee me) ‘ o> i ie r TS er ] LO'SA teal Ar Ye cue ; Ra : aN A Pak ia ahve! aya ml a the eae Sees * or; aes eae’ *, OG Tee a ‘ — = Vy 7 ; ; a | ard sv? + hy » ye Ay i=) A ee 4 a> ¢ : Ce fe ats ‘ ¥ 5 . ‘al oe . i 4 ; ~ | | ‘y . ; ; 4 ' , = “e ¥ a : ‘ave ¥ a ‘ ae y sa ‘ aed , oF - i" v it Se Pere Len is ry ; bs sei Mh, ‘i % ‘| ns 7 q re 7 x J y NYA ree —s Rig a X ne inh : p hap os Mens teeta ts “ : » . 1 ao ee a a q ise. Th re « ] =f . ‘7 y 4 - i ip : 1a ' : j en: Pie eed Ve) ky ’ ae Can 4 Pe aie 1 ee . av. a ee Be ERY a oe ila “ ~ , ® ee* 7. >, 2 “ a t ; tt; , ’ . 3 ‘ rales, “eee Vdut ab ey. were - ie Se 2 ? ‘: S ee ee " as oo yf ies < vee te gee! * re f J. ELIOT, Jour. As. Soc. Bengal, 1884, Vol. LIII, Pt. II. Plate VII. Tra NOV. 1888. Lithographed at the Survey of India Offices, Calcutta, September 1884. RBM Saree es ae.” poe ep Sater a: 1 Av Piate VIII. 9ta NOV. 1888. a ak es eek eee ae oe } 7 o “ a aa 10ta NOV. 1883. Lithographed at the Survey of India Offices, Calcutta, September 1984, ¢ / F } ; — Plate: IX. J. ELIOT, Jour. As. Soc. Bengal, 1884, Vol. LIII, Pt. II. llth NOV. 1883. 12tTe NOV. 1883. Lithographed at the Survey of India Offices, Calcutta, September 1884. oie es ele ’ , Be J. ELIOT, Jour. As. Soc. Bengal, 1884, Vol. LIII, Pt. II. Plate X. 18TH NOY. 1888. bie Miss - on = — | : Yi \ LNG ae. Yo. 7” \ Shag ogy ees VAX ees fs oe \ —— — Ss, eh PSN Lithographed at the Survey of India Offices, Calcutta, September 1884. J te ay + ‘ ei ‘ » (di eRe a 2esnrida apeaued zo. Diipatncaetes : { = 4 | | : | : i % ; % > tee "wea t i Nan dl 4 ies a : r fe +: ti. af ;* ; y fi ee ‘ a ‘wea! VOW wit j eee NL AC 110) Ee he ¥ s Me” 4 AP ‘4 a ifs f ana “os iy “i te inge a Lg aad rT io Ia PN Ay ei 9 | way wae it A; Dyer. ;.' TS nile i aon Neem JOURNAL OF THE ASIATIC SOCIETY OF BENGAL. —_—-)>— Part II.—NATURAL SCIENCE. No. ]I.~1884, — eee IlI.—Accownt of the South-West Monsoon Storms of the 26th June to Ath July and of 10th to 1ith November 1883.—By Joun Exiot, M. A., Meteorological Reporter to the Government of Bengal. [Received June 4th ;—Read July 2nd, 1884. ] (With Plates II—X.) ad ' CHAPTER I. INTRODUCTION. : It is proposed in the following paper to give an account of the © most important and remarkable storms that occurred in the Bay of ngal during the year 1883. The first storm was generated during > last week of June near ‘the Head of the Bay and gave very stormy ather off the Bengal and Orjssa coasts, and was the only occasion on it was necessary to hoist the storm signals at the Saugor Island station near the entrance to the Hooghly. The second storm was formed in the Gulf of Martaban durig the second week of November, almost at the end of the south-west monsoon, and pursued a very unusual course. It crossed into the Bay of Bengal through the channel between Cape Negrais and the Andaman Islands. It then slightly recurved and moved in a general northward direction, approaching the Arracan coast near Akyab, where it was broken up by the action of the Arracan Hills. 8 54 J. Eliot—The Suoth-West Monsoon Storms [No. 2, The following is a list of all the cyclonic storms in the Bay of © Bengal during the south-west monsoon period of the year 1883. They were all of comparatively small extent and intensity, or ordinary south- west monsoon storms accompanied with winds of force 8 to 10 at and near the centre. 1. Storm of June 13th to 20th at the commencement of the south- west monsoon, which gave thesfirst heavy burst of rainfall to Behar. It formed near the Balasore coast on the 13th, and advanced into Behar, where it broke up on the 20th. 2. Storm of June 26th to 4th July. This was generated slowly near the Sandheads on the 26th and 27th, was of considerable intensity, and remained nearly stationary until the 29th. It crossed the Balasore coast early on the morning of the 30th. 3. Storm of July 6th to 8th. This was formed at or near the Sandheads under similar conditions to the preceding, but was of small intensity. It crossed the Balasore coast on the afternoon of the 7th. 4. Storm of the 12th to 14th July. This began to form on the morning of the 12th off the South Orissa coast, across which (between False Point and Gopalpore) the centre advanced on the evening of the 13th, or early on the morning of the 14th, into the Central Provinces. It was of slight intensity. 5. Storm of the 16th to 18th Abed: This was formed in the north-west angle of the Bay, and crossed the North Orissa coast near Balasore. This storm was very small, of very slight intensity, and of no importance. 6. Storm of the 23rd to the 26th of August. This was generated further to the south than the preceding storm, and crossed the Ganjam coast between Gopalpore and Vizagapatam on the evening of the 25th. It was of slight intensity. 7. Storm of the 30th August to the 3rd of September. This depression crossed the coast near Balasore on the afternoon of the 2nd of September, and was of moderate intensity. 8. Storm of the 6th and 7th of September. This was formed im- mediately after the preceding, and followed along nearly the same track, crossing the Orissa coast to the south of Balasore on the morning of the 7th. It was of small intensity. 9. Storm of the 11th to the 15th of November. This was genera- ted in the Martaban Gulf, and advanced in a north-westerly direction as far as Lat. 16° N. Long. 93° E. to the west of Diamond Island, when it recurved and moved northwards parallel to the coast, breaking up in the neighbourhood of Akyab during the afternoon of the 14th. This was the most severe and intense storm of the year in the Bay, but was fa 1884.) of the Bay of Bengal in 1883. 55 of very limited extent, and hence did not affect the weather in the north- west angle of the Bay. 10. Storm of the 2nd to the 4th of December, which gave heavy rain at a very unusual time of the year to Bengal. Two of these were remarkable for the length of time that elapsed before they broke up after they had crossed the Bengal or Orissa coast, and also for the very heavy rainfall and floods which accompanied their existence on land. The first of these was the storm of June 13th to 20th which was formed in the immediate neighbourhood of the Balasore coast. It drifted through Chutia Nagpur and South Behar into North Behar and gave excessively heavy rain to a narrow area in Behar stretching from Gya to Motihari and Durbhunga. This storm was of little importance at sea. The second storm of the series was similar in its general character. It was generated near the Head of the Bay, crossed the North Orissa coast, and advanced over the Orissa Hills into the Central Provinces. Instead of breaking up as do three out of four storms or cyclonic circulations which pass from the Bay into the Central Provinces, it acquired fresh energy and drew large supplies of vapour from the Bom- bay monsoon current. It advanced across the head of the Peninsula almost parallel to the valleys of the Nerbudda and Tapti. The heavy rain accompanying it caused excessive floods in these two rivers which in- flicted much damage on the town of Surat, and others in the lower portion of the valleys of these two rivers. This cyclonic circulation apparently broke up in the Arabian Sea in the immediate neighbourhood of the Guzerat and Sind coasts. The meteorology of India for the year 1883 was remarkable in several respects. One or two of the more important features had a direct bearing on the number and character of the cyclones. During the cold weather months several storms of unusual character and magnitude passed over Northern India and the Himalayas from west to east. They gave excessive snowfall over the higher Himalayas and affec- ted the weather certainly for many weeks and probably more or less per- manently for the year. The accumulation of snow reduced temperature for some time and gave a strong northerly element to the air motion or wind circulation over Northern India. The south-west monsoon set in about the normal period on the Burmah and Bengal coasts, but it never obtained its usual hold in Northern India. The rains were irregular in occurrence and distribution, and much below the average over the whole of Northern India. The deficiency was quite as marked in North Bengal as in North Behar or Rohilkhand or in the Western districts of the Punjab. The monsoon was in ordinary language very weak, and 56 J. Eliot—The South-West Monsoon Storms [No. 2, its weakness was more especially shown in Bengal by the early and complete termination of the rains in the last week of September. The only theory which on the whole explains the phenomena of cyclonic generation and motion, viz., the condensation theory, indicates that small cyclonic storms should be of frequent occurrence during the south-west monsoon, and that they should be most frequent when the monsoon is weak on land, or in other words, when the rainfall occurs to a smaller extent over the land and therefore usually to a ereater extent over the sea area in the neighbourhood of the land. The rainfall in the Bay near the Burmah, Arracan, and Bengal coasts during the south-west monsoon of 1883 was, according to the various accounts received in the Meteorological Office, noticeably larger in amount than usual. The large number of cyclonic storms which formed during the period the south-west monsoon prevailed in Northern India in the year 1883 confirms this inference from theory. After the south-west monsoon current finally retreated from Nor- thern India in the last week of September, it recurved as usual over the Bay. The moisture brought up by it was, however, at once dis- charged on the Madras coast districts. The condensation theory indi- cates that there is a marked tendency during the transition period of October and November to the commencement and continuance of heavy rainfall over the centre of the Bay, and therefore to the generation of severe cyclonic storms at that period. If, however, the aqueous vapour — or moisture is not discharged as rain over the Bay, but is carried west- wards by the north-east monsoon winds and deposited on and near the Madras coast, the conditions for the formation of a cyclonic storm are not present in the Bay. In other words, if heavy general rain sets in and continues over the Madras coast at the change of this monsoon, the Bay will be free from severe and extensive storms. This rule was strikingly illustrated by the weather of the Bay and the Madras coast in October and November 1883. The paper will deal with the subject under the following heads :— 1. History of the Storm of June 26th to July 4th. 2. Discussion of the more important features of the Storm of 26th June to 4th July. 3. History of the Storm of 10th to 15th November. 4. Discussion of the more important features and peculiarities of the Storm of 10th to 15th November. 5. General remarks on the generation of cyclones. 1884.] of the Bay of Bengal in 1883. 57 CHAPTER II. HIstory OF THE StoRM OF JUNE 26TH TO JULY 4TH. The south-west monsoon set in slightly earlier than usual on the Bengal coast in 1883, but with no great strength. Moderate rain fell over the whole of the Province of Bengal during the first fortnight. On the 12th there began to form, in the north-west angle of the Bay, between False- point and Saugor Island, and over the adjacent portion of south-west Bengal, a small barometric depression ; and on the morning of the 13th, the winds in South-west Bengal and North Orissa indicated cyclonic convergence to it. The depression intensified on the 14th, and its centre was then to the north of and in the neighbourhood of Balasore. It advanced northwards through Chutia Nagpore and South Behar across the Ganges into the central districts of North Behar, and gave excessive rain over a narrow area stretching from Gya through Behar and Patna to Mozufferpore and Durbhunga. Amongst the remarkable rainfalls were the following :— ESE ee ee | 15th 16th 17th 18th 19th LL | | | | en Gya 101 9:04 Q:21 0-01 nil Behar ae: een Die? 6°05 10°95 0°58 0:09 a 0s: iste «5 aa vi dke ae Be.ne 1:23 6°35 a hs nil. 0:05 Mozufferpore ............ 0:08 2°85 12°49 0°42 nil. SPOPIEEMCT Ss ....0400..-0.-- | 0°86 Ar51 9°39 nil. 0-14 Purbhunge .i............ 0:53 1:02 502 8:52 0:24 The disturbance broke up in North Behar and finally disappeared on the 20th. During the next five days there was a partial break in the rains. The air was drier, sky less clouded, and rain showers local rather than general in character. The winds more especially diminished in strength, but continued to indicate the same general atmospheric motion over the Gangetic delta and valley as before. Southerly winds blew across the Bengal coast. In Northern Bengal and Behar the current was deflected up the Gangetic valley and hence gave winds blowing from directions varying generally between N. H. and §S. HE. In Chutia Nagpore. and in Western Orissa the effects of the Bombay branch of the monsoon current were beginning to be shown by the prevalence of moist 8.8. W. winds at Hazarabagh and of W.N. W. 58 J. Eliot—The South-West Monsoon Storms [No. 2, winds at Cuttack. The Bombay branch of the monsoon current, it may be added, was late in being established on the Bombay coast, and was very feeble before the 20th of the month, when it rapidly in- creased in force, as measured by the strength of the winds. The heavy rainfall attending the disturbance of the third week of the month had drained the southerly monsoon winds advancing into Bengal from the Bay of a very large portion of their moisture, and weakened them for some days. This is shown by the diminution in the amount of the rainfall and by the decreased velocity of the winds in Bengal. The following table gives the average amount of the rainfall day by day between the 13th and the 26th in the various divisions in Bengal, and illustrates fully the general diminution in the rainfall of every part of the Province after the 20th :— Table of Average Rainfall recorded in Bengal, June 13th to 26th 1883. w q & 3 PROVINCE. |%H So] ee Ss ee ee ee ee ft A Vi Pe) fc SO dea A Orissa......... 16| 0°64) 1-30] 0°23] 004) 0°25] 0°16] 0°30} 0-09) Nil. | 0°37) 0°10) 0:48 é. 0°41 S. W. Bengal |46/ 0°31] 0°78] 0°42) 0°26] 0°27] 0°26] 1:02) 0-31) 0:66) 0°26) 0:45] 0°10 a 0:07 Kast Bengal |26/ 0°18) 0°51) 1°62/ 1°11| 0°86) 1°00) 1°48) 0°46) 0°82) 0°33) 0°17; 0°18) 0°16 0°11 0°33) 0°72| 1°09; 0°98, 0°96 0°42) 0°30) 0:07| 1:98 0°89 | 0°09| 0°38, Nil. | 0°38 0°77 North Bengal}27/ 0°09) 0°21) 0°91) 1°79} 1°71) 0°4'7/ 1:23, 2°25) 0°97 North Behar |16) 0°04) 0°12) 0°52) 1°86) 3°69) 1°36) 1°13) 1°21] 0°42 South Behar |17| 0°29) 0°08] 1°40) 3°37| 1°99] 0°92) 0°35; 0-11) 0:04 | 0°63! 0:97] 0:15! 0°37 Chutia Nae- pore &Son- ¢ |16] 0°39} 0°50} 2°04; 0°48) 0°21) 0°56 thal Perg. 0°13, Nil. a 0°35 The following table gives the daily amounts of wind for the same period at.the chief Meteorological Stations in Orissa, Bengal, and Behar. in re at « pial a, Sg of the Bay of Bengal in 1888. 59 Table of Daily Amount of Wind at eight Stations in Bengal. June 13th to 25th, 1883. Average Daily Amount, June. 244) P | 285) 238 bo Pod © False Point ... | 261) 207 / 151] 122) 72) 104 162 211| 181) 142) 155) 186 120) 120) 144; 120] ? Purneah ...... 76| 100} 170) 111} 126; 114 24, 26) 21) 47; 29) 98 74, 127| 57) 59} 116) 134) 137 121} 138} 55) 111) 107| 127) P EID, os see +e 117) 148) 206) 251, 114) 58 153] 239} 136) 211) 182) 178) 214 Hazaribagh ... ” 134, 191) 286 ee 182) 206 The rainfall table shews a very marked diminution in the amount of rain after the 20th. An examination of the complete rainfall returns of the Province of Bengal indicates that it occurred as isolated and local showers, which were occasionally heavy and gave large amounts at single stations. No general rain, however, fell over any considerable portion of the Province between the 20th and 25th. Similarly, an examination of the second table giving wind amounts indicates that, although strong winds generally prevailed between the 13th and 20th, winds were unusually light after the 20th and below their normal strength. This feature of weakness of its air motion was most markedly shown by the stations most distant from the sea, as, for example, Purneah. The meteorological observations taken in Bengal thus show that what may be termed a strong monsoon prevailed at the Head of the Bay and in Bengal from the 1st to the 20th of the month, and.that for some days afterwards, or between the 20th and the 25th, it was much feebler. Also, as will be seen from the following observations and from the history of the storm, the south-west monsoon winds increased in force to the west of the Andamans on the 23rd, advanced northwards as a strong atmos- pheric current along the coasts of Burmah and Arracan, and fed the cyclonic vortex which formed on the 26th and 27th with large supplies of aqueous vapour. 60 J. Eliot—The South-West Monsoon Storms [No. 2, Table of Daily Amount of Wind at seven Stations to the east of the Bay. July 22nd to 28th, 1883. Average! gond.| 23rd. | 24th. | 26th. | 26th. | 27th. | 28th, SE Nancowry ....cecsecseseeees 263°5 | 115°0{ 98°8| 97:3 | 1242 | 252-7 | 354'5{ 289°8 Port Blair 5).¥sc.cch. si. 257°6 | 128°7| 212°9/ 386-0 | 283'8 | 305-4 | 315°6| 323-0 Diamond Island............ 2030 | 1229] 118°5/118-7 | 240-7 |310°4 | 346°6| 336-5 pin a OR al ened 93°6 | 427] 48:9] 55:4 | 83°6 |100°9 | 153°8] 234-4 Chittagong .........ccccc 168°3 | 162°6| 113°5| 72:9 | 71:9 | 501 | 117-7] 212°2 Sangor Island ........060 332'4 | 362°7| 312°4| 284-7 | 235-2 |1445 | 1387-1] 357-4 THESES be SR ae le a 183°7 | 211-1] 181°1|142°8 |155°0 | 688 | 668} 181-1 The preceding table shows that on the 22nd and 23rd the winds were barely half their normal strength over the east of the Bay. A rapid increase took place on the 24th at Port Blair, which extended to Diamond Island on the 25th and to Akyab and Chittagong on the 26th and 27th. These figures suggest what is also indicated by the whole of the Bengal observations, viz., that the weather in the Bay between the 20th and 28rd of June was that which usually accompanies the commence- ment of a partial break in the rains in Bengal or Northern India. Winds were light and unsteady over the whole of the north and centre of the Bay. The logs of vessels show that occasional rain-squalls local in character occurred, more especially in the south of the Bay. The observations at Port Blair, Nancowry, Diamond Island, and Akyab and of the ships traversing the Bay at the time, however, prove conclusively that south-westerly winds prevailed over the whole of the Bay ; and the Bengal observations establish that they were continued in Bengal and Behar as southerly and easterly winds. They also indicate that on the 24th a change occurred in the character of the winds to the west of the Andamans which lasted for some days. A very considerable increase occurred in the south-west winds of that part of the Bay which rapidly and steadily extended northwards. Hence prior to the morning of the 25th the gradients were normal in direction, although smaller in amount than the average for the season, over the Bay ; the winds blew from the usual quarter and gave rise to the normal atmospheric current up the Gangetic valley. The only indica- tion afforded at this time by the land observations of the subsequent stormy weather was the occurrence of a partial break in the rains, which, as has been ascertained by previous experience, establishes conditions which are favourable to the development of a cyclonic disturbance if an adequate motive power or disturbance act on the atmosphere. 1884.) of the Bay of Bengal in 1883. 61 The account of the storm of the last week of June hence begins with the 25th of June, the day before which there were any indications of the actual formation of an atmospheric whirl at the Head of the Bay. 25th of June.—The atmosphere was in a slightly disturbed state over nearly the whole of India. The barometer was rising in the North-Western Provinces, Bengal, and the south of the Peninsula, but elsewhere it was falling. A large depression accompanying the establish- ment of the south-west monsoon in Western India was advancing along the west coast of India and causing the barometer to fall quickly. Winds had backed to south-east on the 24th at Bombay. On the 25th, winds were southerly along the Bombay coast and easterly in Cutch. There were strong indications that gales of considerable force were blowing on and near the Bombay coast. The weather was cloudy every- where, except in the Punjab; and rain in small or moderate amounts was falling in every part of India, except the Punjab, Behar, Sind, and parts of the Madras Presidency. The rainfall was very small in amount and local in its distribution over the North-Western Provinces, Bengal, Rajputana, and the North Bombay districts. The following table gives the more important observations taken at the Coast Stations on the Bay of Bengal on the 25th June, 1883 :— © : — S és 4 e £ SO om * * ° bB . o 5 z = Wind direction. 5: 3 & ° E 3 see Rainfall STATIONS ife Oo eax aiSgé BS of ; 233 bp = Paadge = previous ee See (deh | dew (Seeles °| 124 boars. Ey | o8 SSEOE om oF Nancow’y...... 29941 | +°047 |S.8.W.|S.S.W.} 5 45 8 0°14 Part Blair .:.... 29911 | + -060)|): S. W.. |. 8. W. 14 | 127 10 1°05 Diamond Island} 29°847 | + °024/ S.W. |W.S.W.| 8 | 100 9 0°24 MEVED ......... 29°792 | + 019 | H.S. E. Ss. 4 | 100 9 1°35 Chittagong ...| 29°802 | + 027: S.E..| 8S. W. 3 43 10-4" "O16 Dacca ......... 29°752 | + ‘024 S. S. E. 7 88 10 Jessore ......... 29°745 | +°040| calm. |S.S.W.; 7 | 140 8 Calcutta (Ali-| 29°719 | + -025 s. S.S. W. 5 83 9 0°05 pore) +/........ Saugor Island | 29°775 | + ‘053 8 S.S.E.} 381 | 221 3 0°21 3 Balasore ...... 29°715 | +010] S. W. P 5 P 62 J. Eliot—The South-West Monsoon Storms [No. 2 3 : rn re 2 9 Wind direction. |, & = g Seer 3 SS) a= x mos o.ae 3 | Rainfall STATIONS 43$ at Sage oa| Bo of - | a88) be Pg alaks <6 | previous mgs ie 10h. 16h Tee pg 8 ret (24 hours. ao) | i) S Dla a ates) Apes a Cuttack......... 29°695 | + °015 |W.8.W.) ° S. 3 75 9 1-01 False Point ... | 29°722 | + :°005 | Calm. K. 11 110 8 0°03 Vizagapatam | 29°672|—-‘027| W. |W.byS8. 6 | 150 8 Pressure had increased rather rapidly over the province of Bengal during the previous 24 hours. The general result of the changes of pressure since the dispersion of the disturbance of the third week of the month had been to give a high barometer, which culminated on the morn- ing of the 25th in excessively high readings. The barometric readings at 10 a. m. of that day in Bengal were above the average by amounts which varied from ‘19’ at Saugor Island to -09" at Durbhunga. Winds were, however, generally normal in direction, blowing from south in South-West Bengal, south-east in Hast Bengal, east in North and Cen- tral Behar, and south-west in Chutia Nagpore. The unusual weakness of the wind is shown by the following com- parison table :— Wind amount} Average Percentage of 24 hours | daily wind | of actual to preceding |amount June.| average wind 10 A. M. amount. Samcor Island: ..cLiseceseeenmeenee oss ne 256°9 332°4 77°3 Caleniita «°c. eslis,bca tenner eee see he 104-0 152°3 68°3 Berhampore... :..as>sorarreeeree eects 132°6 132°3 100°2 TACOS: 5 « .ccenn aerate karo ueenet ees ekeLen 16271 183°7 88°3 PERSOLE | 0's acinancins nin tpaey pemaran soba vere 118°3 118°3 100°0 SORA D ONS |... .dvs.c.ceteteesmneee -ivceeee 715 168°3 42°5 PS AEWAIN ile isecie sn'nce Socidye eee» ohelee 110-7 1242 89°1 OCI 33... a Letts wale a peweseeeees chine 40-0 96°3 ALS Balse Poms +. ga tet ace ae 263°3 24:7°2 106°5 The average rainfall in each of the seven meteorological divisions of Bengal for the 24 hours preceding 6 Pp. m. of the 25th June is given in page 58. The following table gives the meteorological information for the 25th extracted from the logs of vessels :— : 1884.} > Vessel. - Bancoora Himalaya Roma...... Hour. of the Bay of Bengal in 1883. 63 REMARKS. | a, og S 26 - 3 é es rs Wind a a = "Bp gcd oO 8 8 S g 8! pir. [Force | A = 29'899|8.S.W.| 3 80°988} N. E. 2 N. E. 5° 58’ | 80° 58’ °963|) W.S. W. 3 by D. R. 29-889} S. W. 901} S..W. 3 °889| S. W. 3 s. 4 29°750| N. W. 3 ef KE. 15° 10’ | 83° 14’ “730, W. 3 W.. 730) W. 4, "730| WW. 3 29°712/S. S. W. N. E. 7WA7\W.S. W. 15 49" 82° 207) “737 S. W. 3 -731|\W.S. W. 734) S. W. 757| S.W. Ss. W. 5 17 15") 85° 17’ lee 0 to 3 8 A.M. Light breeze and hazy. 11 4.mM. Heavy rain squall. Noon. Moderate breeze and fine. Midnight. Moderate breeze and clear. Moderate breeze with passing squalls. Breeze moderating and fine. Moderate breeze and fine. Moderate fresh wind; cloudy with showers. Fresh breeze and overcast. Threatening toN.W. with lightning. Moderate breeze and overcast. Fresh breeze and moderate sea. Moderate variable wind with very heavy rain squalls and dark overcast sky. Rain squalls. Lightning, similar weather and high S. S. W. sea. Overcast sky. 64 J. Ehot—The South-West Monsoon Storms [No. 2 nner nnn r erence nr oO oO oe.: : ig Ef 2 2 8 Wind. Vessel. Hour.| # ‘h 128 8 é REMARKS. S a ae ° eo) Pan re) : is re get a ee Fe Saint Magnus |4 A. M. 29°690 |W. S. W.| 4 8a.m.| N. K. ‘700| 8. W. 4. Noon |18° 31/86 29'| -710| W. 1 4 Pp. M. “680 S. 1 | Calms and rain. 8 Pp. M. 2i00\ 8.7 5 | Cloudy, lightning to S.W.&8.E Star of Albion |4 A. M. 29°730 8 a.m} N. EK, “740 Easterly current. Squally. Noon |18° 46/86° 40 °740| W. |4to5| Cloudy weather. 4 P.M. “710 8 P.M. "720 Scottish Chief- |8 A. m. 29°680 0 | Very light airs and dark tain NN, EK. cloudy weather. Noon |18° 58/86° 34’, ‘690|S. by W.| 1 4 P.M. S. W. | 2 | Strong westerly current. 8 Pp. M. “660|N.N.W.| 3 British Princess |4 A. M. S. by W.| 5 | Cloudy sky and 8. W. swell. 8 a.m] S. W. | 4] Variable winds. N. EK. Noon | 19° 9 /85° 15429°700) ‘EE. 2 | Fine clear weather. 4 P.M. E.S.H.| 4 | Squally with rain. 8 P.M. S. 3 | Cloudy sky. Midnt. W.S.W. 4 |S. W. swell moderating. S. 8. E. Midnight. Prince Amadeo |4 A, M. S. W. 4.{ a.m. Weather clearing,, wind moderate. 4 A.M. Gentle wind, fine wea- ther. Noon. Closesultry N. E. weather. Sea smooth. Noon |19°% 23//85° 56129°700 s. 4 4 P.M. EK.S.E.| 3/4 p.m. Weather fine _ Sea very smooth. Comumilla ...... |8 A.M. Variable} 2 | Showery. N. BR. Noon [207 13492° 28 S. E. 8 |Clear weather and smooth sea. 4P. M. 29°611| 8.8. E.| 3 | Fine weather. 8 P. M. 683; 5S. HE. 4 | Fine weather and light- ning to eastward. Midnt. ‘671; H. 8S. E.| 41|]Clear weather and smooth sea. 1884.) of the Bay. of Bengal in 1883. 65 The logs of the vessels received in the Meteorological office give an imperfect view of the weather in the Bay, as they were chiefly those of _ steamers passing up to Calcutta along the west coast of the Bay. The Bancoora rounding Ceylon had light to moderate south-west breezes (force 1 to 3) during the day. The India and Himalaya were a few miles apart off the coast to the south-east of Coconada. The former was in Lat. 15e 10’ N. and Long. 83° 14’ E. at noon and the latter in Lat. 15° 13’ N. and Long. 82° 29’ HE. Both had moderate breezes and overcast skies. The winds were of force 3 and from directions between W. and S.W. The Roma, in Lat. 17° 15’ N. and Long. 85° 17’ E. at noon, had moderate variable winds with calms and very heavy rain squalls. The Star of Albion, Scottish Chieftain, and Saint Magnus were all near each other off the Gopalpore coast. The winds were very light and unsteady, but were generally from directions between west and south-west. The - Scottish Chieftain had calms at 8 A. M., and the Saint Magnus calms and rain at 4 p. m. The British Princess and Prince Amadeo were a little further to the north. The former, in Lat. 19° 9' N. and Long. 85° 15’ H. at noon, had variable winds during the day varying in force between 2 and 5. The latter, in Lat. 19° 23’ N. and Long. 86° 56’ E., had gentle south-west winds, sultry weather, and a smooth sea. There were hence no indications on this day of the existence of an atmospheric whirl in the Bay. 3 26th June—During the previous 24 hours the barometer had risen rapidly at the Bombay stations, and the depression off that coast was much less marked than on the 25th at Bombay and the adjacent coast stations. South-westerly gales were blowing, but the rainfall brought up by them was as yet moderate in amount. In parts of Southern and Central India the barometer had also risen, but over the whole of Northern India a considerable fall had taken place. Along the foot of the hills, from Assam to the Punjab, the wind was generally easterly or north-easterly, and in the Central Provinces and Central India it was westerly. The weather was dull and sky overcast over the whole country except the Punjab, and rain was falling except in North-Western and Central India, but the amounts registered were in the great majority of cases small. The rainfall returns, as compared with the average rainfall between June Ist and 26th, shew that there was a deficiency of from 1 to 3 inches over the plains of the Punjab, the western half of the North- Western Provinces, Central India, and Rajputana, and of 7 inches in Bombay. The following are the more important observations taken at 10 A. M. of the 26th at the selected stations near the Head of the Bay :— 66 J. Kliot—The South-West Monsoon Storms [No. 2, 4,38 a Average a n e222 jo Wind. wind 0 le il 5 2 Gao Shae: velocity | 3B 5 See STATIONS. HSy 5(S-8 4 of ES Sol san -O0 or Qs; = =) Ry 4go |O <“/ 10h 16h. [previous a ae a= ay = 24 hours. Ra ~ Nancowry ......... 29°915 |— 026) S. W. | S. W. 11 100 | 7 Port Blair: >. :..<;. 29°886 |—°025) S. W. S. W. 11 100 | 10 0°32 Diamond Island...) 29°801 |—‘046] §. a. W. 10 125 | 8 1°26 PVR es aki ae vorvas 29°711 |— 081) S.E. |S. 8S. E. 4. 100 | 9 1:98 Chittagong......... 29660 |—142) s.H. | &. 2 29| 5}. Ol Dacca ...........4+..| 29°682 |—°070|_—S. Se 6 75 | -O-/ D6T JOSSOTO. ..ccccsense 29°673 |—°072| 8. Ss. 6 120 | 10| 0°04 Calcutta (Alipore)| 29°646 |—‘073) E. S. E.| E. by 8. 3 50 | 8&1 Ove Saugor Island ...| 29°647 —-‘128] S.E. |E.S. E. 7 50 | 2; 0-08 Balasore .....5<....- 29°636 |—‘079| N.N. E. P 2 p 6 Cuttack ............| 29°626 |—‘O69/S.S. W.| Calm. 1 2b 19 0°12 False Point. ......| 29°621 |—°101|} N. E. K. 8 80 | 4 Vizagapatam ...... 29°668 |—°004| W. W: 5 125 |, 6.) O80 Pressure, it will be seen from the above, had given way, and the fall was greatest at Saugor Island and Chittagong. This was due, as shewn by the wind directions, to the formation of an area of cyclonic distur- bance and barometric depression near the Head of the Bay. The winds at Saugor Island had shifted to south-east, at False Point to north-east, and at Gopalpore to north-west. From the information extracted from the logs, it will be seen that light north-east winds were established over a considerable portion of the north-west of the Bay. Hence, the cyclonic circulation was just beginning to affect the direction of air mo- tion at Saugor Island and was causing it to back. It was, however, not yet participating directly in the cyclonic indraught. The sky was more or less clouded in all parts of the province of Bengal, the air very damp (especially in Behar, after the floods of the previous week), and winds unusually light and somewhat unsteady. The following table gives the average rainfall in the seven divisions of the province of Bengal for the 24 hours preceding 6 P. M. :— 1884. ] of the Bay of Bengal in 1883. 67 Table of Average Rainfall in Bengal on the 26th June 1883. + Name of Province. Average Rain. Origa ick Faselives te vidas: (0 et South West Regal: ard suns ONL MREN SSOMEIENT Cac ctden ssn see dona ceurdsoy UL North eis Mishingaayaa cea bedteaice ay ae North Behar... ae. ae cidaavay OES South Behar... seve dove tO" Fe Sonthal Pengannabs a ere emer a 0-35 Chutia Nagpore .. BAasuids The following extracts from the logs of vessels give information respecting the Bay on the 26th :— a aaa aaa) ‘S 3 Probable Wind Vessel. Hour. z % scien 3 a 5 & | meter. Dir E Fy Bancoora | 4A. M. 29°876 |SW.byS.| 2 |44.M. Light breeze and fine. 8 A.M 883 |SW.byS.| 2|8 4. mM. Light follow- W: EK. ing wind and clear. Noon | 8° 35’ |82° 35 ‘863 |S.W.byS.| 2 4 P.M. ‘780 |W S. W.| 2 oP Ww. *856 |S. S.W.| 2 Midnt. 816 |S. 8. W.| 3 | Evening. Moderate breeze and fine. N. K. Pemba ...| Noon {16° 46’96° 12’ 104. mM. At Rangoon. 4 P.M. S. W. 5 Unmoored and pro- ceeded towards Cal- cutta. Midnt. 29°750 =. 5 | Midnight. Fresh to mo- derate breezes and frequent rain squalls. Himalaya | 44. M. 29°657 Ww. 8 A. M. 635 W. iN. E. Noon |17° 32’84° 38) 615 Ww Moderate breeze and overcast. 4 P.M. 506 | S. W. 8 P. M. "086 |W.S. W. Moderate breeze and Midnt. 539 |W. S W. fine. Star of Al-| 8a.m. | N. EK. 29°700 Principally light. un- bion Noon {19° 21’\86° 20° *630 |W.toSW|4to2|) steady winds, finer at & N. W. night than in the day 4 P.M. *620 time. 68 J. Eliot—The South-West Monsoon Storms [ No. 2, oa : = f 3 2 Wind. Vessel. 5 2 h |28 ap x 3 8 x ae Dir Force British Prin-|4 A. M. W.S. W. 4 cess 8 A. M. W.N. W. 3 N. Noon |19° 30‘ 87° ‘3 29°600|) N. N. E. 4, 4 P.M. E.N. HE. 3 8 P. M. EK. 0 to 3 Midnt. W.N. W. 5 Ch ae 4A. M. W. 4, 8 A. M. 29°610| N. by E. 3 N. E. No on|19° 367/869 33’, “630 nt 3 4 P.M. °630) N. BH. 8 P. M. *590| Calm. Midnt. *580| N. EH. 3 Saint Mag-|4 A. Mm. 29°610; W 4 nus Sar as N. EK. "610 N. 2 Noon |19° 47487° 18% °600) N. E. it 4 P.M. °530 E. KE 8 P.M. *590| N. W. 1 Midnt. *550| N. W. 5 Prince Ama-|4 A. M. N. Light deo N. K. Noon |19° 52’'87° 9’ 29°600|N.to NE.| Light. W. to 8 P. M. W.N. W.| Gentle. Scottis h4 A.M. 29°640|S. 8. W. 0 Chieftain.|8 a.m.| N. E. S. H. 1 Noon |20° 04’ 86° 58’, ‘600| HE. 2 4 P.M. E.S. EH. 3 8 Pp. M. E.N. E. 4, Midnt. *580| S. H. 4, REMARKS. Dark cloudy sky. Light green sky. Weather fine and clear with 8S. W. swell. High southerly swell and cloudy, the stars showing through with great brilliancy. Strong winds & squally with clouds. Moderating breezes and cloudy weather. Moderate breeze and cloudy. Moderate breeze, fine. Calm and clear. Moderate breeze with passing clouds. Cloudy weather. ¥ ; Faint airs and calms. Faint airs, calms, heavy southerly sea. Cloudy with lightning. Cloudy. 4 A.M. Heavy cloudy and unsettled looking weather. Much light- ning and southerly swell. Noon, simi- lar looking weather, light variable airs; — unsettled looking all round, high souther- ly swell. 8 P. M. same weather, much lightning. A strong current set- ting about W. Winds very unsteady in force and direction. oe". ae A of the Bay of Bengal in 1883. 69 ¢ | legs fc?) : = ot @oR REMARKS. = 3 a S 5 Dir Force. py W. 4 A. M. swell from S.S. W. overcast sky and rain. North 3 |8A4.M. Gentle breeze, sky clearing at inter- N. E. vals. Noon |20° 19/86° 50’ N. 8 | Noon, similar weather with southerly swell, light breeze, sky clear- ing at intervals. 4P.M N. E. 1 midnt N. E. 1 | 10 p.m. light showers. Commilla ...|4 a. M. 29°635] EH. N. E. 3 | Light cloudy weather. 8 A.M 642) HK. N. EH. 3 N. EK. Noon ,22° 21491950’) °607| E.N. E. 4. 4p. M. Kast 4| Threatening appear- ance to §. EH. Squally with very heavy rain. 8 P. M. 543) 8. 8. HE. 4 | Continuous heavy rain. The Nancowry and Port Blair observations prove that strong steady south-westerly winds continued to blow in that part of the Bay. These winds were also extending to Diamond Island. The average wind velocity during the past 24 hours at that station was 10 miles, and for the previous day had been 8 miles per hour. The sea was also reported to be rising. Hence it is certain that the vigorous current indicated by the strong winds at Port Blair on the 25th was steadily advancing up the east of the Bay, and that its front was off the West Burmese coast on the morning of the 26th. The Pemba, which left Rangoon at 10 a. m., had south-westerly winds of force 5 with frequent rain squalls, as she ad- vanced westwards in the Martaban Gulf to the south of the Burmese coast. It is almost certain that this strong current was giving heavy rain over a portion of the north-east of the Bay in the neighbourhood of the Burmese and Arracan coasts. The direct evidence of this does not appear in the extracts from the logs of the vessels given above, but it will appear in those for the 27th. It is, however, indicated by the large rain- fall at Diamond Island and other stations in South Burmah and in Arracan. For the present we shall accept it as almost certain that in the front 10 70 J. Eliot—The South-West Monsoon Storms [No. 2, of this advancing strong moisture current, where the resistance to its advance was greatest, and where therefore ascensional motion was neces- sarily occurring to a large extent, rainfall of a more or less concentrated character was going on. The current was being deflected to the west by the coast and the Burmese and Arracan hills, and was moving more rapidly in its eastern than in its western portion. Hence probably also arose a strong tendency to an eddying motion in front and towards the west. The various actions going on were thus such as might set up vorticose motion. That such a result was taking place was indicated by the wind observations of all the vessels near the Head of the Bay. The Himalaya, in Lat. 17° 32’ N. and Long. 84° 75’ E., had moderate westerly winds. The India, British Princess, Star of Albion, Scottish Chieftain, Saint Mag- nus, Roma, and Prince Amadeo, which were all between Lat. 19° 20’ N. and 20° 19’ N. and between Long. 86° 20’ E. and 87° 18’ Kast, experienced light unsteady north-easterly winds. The weather was fine and sky clear during the greater part of the day, but became more clouded during the evening. There was a heavy swell from the south during the day. This was evidently due to the strong winds and high sea prevalent in the centre and south-east of the Bay. The only log which gives any in- dication of the subsequent weather is that of the Prince Amadeo, in which the Captain notes that, although light variable airs were blowing, the appearance of the sky was unsettled in all directions. Probably the light green sky to the east noted by the Captain of the British Princess was another sign of the large amount of moisture brought up by the southerly winds in the Hast of the Bay. The various observations of the 26th hence indicate that cyclonic motion on a considerable scale commenced on the afternoon of the 25th over a portion of the Head of the Bay. The atmospheric whirl was fed and maintained by a very strong south-westerly air current moving north- wards up the Bay near the Burmah and Arracan coast. It was appa- rently formed in the front of this air-current, and was causing winds to draw round over the north-west of the Bay. The indraught from that quarter was, however, feeble and unimportant, except as an indicator of bad weather to the south-east. 27th June.—The decrease of pressure which commenced on the 26th had now extended over the whole country. The change was still greatest in the north. Onthe northern frontier of the Punjab, in Eastern and Lower Bengal, and at Akyab the decrease exceeded one-tenth of aninch. It was smallest in parts of Bombay and Madras, where it only amounted to two or three-hundreths of an inch. A considerable depression lay over the Punjab. This, however, is a frequent feature of the hot weather months of June and July in that province. A smaller depression was, however, 4 ; ; m “ ; 7 W ‘ ‘& 7 of the Bay of Bengal in 1883. 71 forming at the Head of the Bay to the south of Saugor Island. Pressure ranged from 29°9 inches in Ceylon to 29°28 inches at Peshawar. The wind was from directions between south-west and west over the Peninsula. In the neighbourhood of the two depressions, cyclonic circulations were established. Up the Gangetic valley the wind had a general easterly direction. The weather was cloudy and gloomy in all parts of the country except in the upper districts of the Punjab. Rain in small amounts had fallen during the preceding 24 hours, except in the Punjab, Sind, and West Madras. The rainfall was heavier on the Bombay coast than it had been hitherto, and strong monsoon winds were blowing there. The following table gives the observations at the selected stations on and over the coast of the Bay on the 27th :— , 884 b Wind ee] &1..(¢e8 S252! So8 ee ee|o8 | Ao la 8B (G92) Fes Oo] Aa | oB SEO Srarrons. as 8&8al das Pele S| S8 fe on s@s3/0 8] 10h. |] 16h, [48 Alm? \a ox fo 2 b is Q, an Mth DIGIT .w.......09. 29°853 | —:033 | S. W. Ss. W. | 13 LIB. 10 Diamond Island ...| 29°763 | —-038 | S.S.W.|S.S. W.| 14 175 8 1°79 Nancowry ............ 29°912 — 003; S.W. |8.S.W.|; 15 | 136 8 RE 29°606 ; —'105 |}8.S.H./8.8S.H.) 6] 150; 10 0°57 Chittagong ......... 29°578 | —'082 |E.N.E.| S.E. | 3 43 4 | 1:02 BOI asc cc sen sts cee 29°566 | —°116 K. K. 3 38 8 1°16 Ee 29°604 | — ‘069 | E. N. E. E 6 120 | 10 0°04: Dalcatta (Alipore) | 29°529 | —°117 | E. 8. B. K. 5 83 9 | 020 Sangor Island ...... 29°5382 | —‘115 |N.N.E.|] N.E. | 35 | 250 7 | 009 Balasore ............ 29°537 | — ‘099 N. P 1 ? 8 0°40 : EON 0 ste sessesene 29°565 | —‘061 | N. W. |N.N.W.! 3 75 | 10 101 False Point ......... 29°544 | — ‘077 We Ws BeW. eZ 70} 10 0°26 Vizagapatam ...... 29°634 | —-034 | Ww. |W.S.W.| 7]| 175] 10 | 1:70 } The preceding observations show that pressure had decreased rapid- ly over the north of the Bay and the adjacent coasts during the prece- ding 24 hours. The fall was greatest in South-West Bengal and more especially at Saugor Island. The distribution of pressure, taken in con- nection with the wind directions at the Bengal and Orissa stations, in- 72 J. Eliot—The South-West Monsoon Storms [No. 2, dicates that there was now a well-defined atmospheric whirl at the Head of the Bay, the centre of which was at a little distance to the S. 8. E. of Saugor Island. Pressure was below the normal for the day over the province of Bengal by amounts varying from ‘1” at Chittagong to zero at Patna. Winds were very light over the whole province. Northerly winds had fully set in over South-West Bengal and Orissa, whilst winds more or less easterly prevailed over Hast and North Bengal, Behar, and Chutia Nagpore. Ths weakness of the winds is shown by the following observations :— Amount of veal Aver age Percentage during wind of nied a 24 hours amount. to average. preceding June. 10 A. M. patente) eens Ee a: Veep 152°3 91:3 PROMI POLE | 25-47. 5. - snes n ; : HE tava E 5 E ® Rainfall gia, (Es 8| 28 |) a /eca| go ocak | BE a qo] 8s oo a| 9 24 hours. aogia™| = 3. \ee.e| > | SU Rohe ee evetes! ol Rise hy Sit ae atl See Nancowry ......... 29°913)+ 001) S. W. Ss. W. 13 118 6 nil. Port Bidir......... 29°856;+ °003; S. W. | S. W. 12 109 6 013 Diamond Island | 29°807/+ -044 § S.S. W. 29 363 9 0°25 a 29°639) + 033 s S.c6 Wh Ae 300 10 6°84: Chittagong ...... 29°571|\— 007 S.E. |E. S. E 9 129 9 381k MEE cc cece cescns 29°526\— 040} E H 6 75 10 0°85 JOSSOFe ............ 29°445\—°159) _-E. |E. S. E.| 6 120 10 0°10 Calcutta (Alipore)| 29°392'\— 137 K. KH. by N. 9 150 10 0°22 Saugor Island ... | 29°374/—*158IN. N. E.|N. N. E. 8 57 10 0°91 Balasore ......... 29°423|\— 114) N. ry 2 ? 10 0°32 Cuttack............ | 29°507'\— 058] calm. | N. W. | 4, 100 10 0°62 False Point ...... 29°452\— :092;W. S. W.|W.S.W.| 10 100 10 4°84; Vizagapatam ... | 29°614—-020| W. w. OS a 0:20 Pressure had given way over the whole of the Province of Bengal, and was below the normal of the day by amounts varying between ‘05” at Patna and ‘25” at Saugor Island. The air-motion over the whole of Bengal was now largely dependent on the cyclonic vortex. In Kast and South-West Bengal winds ranged between east and north-east. Norther- ly winds prevailed at Balasore, and south-west winds at Gopalpore and False Point. The air was calm at 10 a. m. at Cuttack. Over North Bengal, 80 J. Eliot—The South-West Monsoon Storms [No. 2, Behar, and Chutia Nagpore light easterly winds were blowing. The indraught to the vortex had diminished the humidity and cloud-amount considerably in North Bengal and Behar during the previous 24 hours, as shown by the following results :— 10 A. M. Average Average Humidity. Cloud Amount. 27th 28th. 27th. 28th North Bengal ............ 81 73 6:0 40 North Behar .......0: 00.50 79 72 4°8 3:2 South Behar ....,...00s008 80°5 70°4: 6°8 Ara, The rainfall returns for the 24 hours previous to 6 P. M. indicate that moderate general rain had fallen over the whole of Hast and South- West Bengal, and that very heavy rain had been received in Orissa. The following table gives the whole of the Orissa rainfall returns for the day :— District. Station. Rainfall. OOO. 5'can s seicen!s PAliop calles pnp alpuait SURE 0°59 MAGI hts a scvenan tone ttadeesorek 0°60 PGDTOG 4, sos Bsicnacesnc nish neste oe TOTO tea relist eaten na bdikantaeeaes nil. M alse: POMS pardanre tian arse ascedeones 8°04 PML OORALOUS, | ..qxtoiionryouctii er cscndeaa veer 3°68 APPATEIBEGOTO: ..5..00ckeee sve ocreadwe sae 7°50 Pi soins esnsset crus dedoviiee 0°35 CotitaokS)....i.<.:--se> sgugaee eee CO reat nea c evince vennes 1°79 Ue@eatehg?) i) SN, 2°70 J RUPEE oon reat eI Bla caso 5 «cine one 2°80 Chand bait’... ccsupesmeecanncrteet ss. stiles 3°25 Bhuddruck ..... ns Cael s. 2 AR PN 1:78 SON, 5: ants vcs eater eeads pjepis Se aigMabh Pend only Guise ci pt nie inde mM a, NY ole OOM. ... 00.00 dae adenmenesinuingsdepeiuapan abet caine tneamnn:. ) mel 3 tH ea S) = A | |e ° - Nancowry ............ .W. {Ss.8. 10 8 Mart Blair ........... ye S. 12 4 Diamond Island ... 8.0.1 8, RIE RS ERT aan BT occas nsc 516 | +°172 | S. EH. 12°0 9 ’ EE icaionh of the Bay of Bengal in 1883. 101 30th June 1883. . E 3 Fs z Wind. Be: ; By tO Vessel. | Hour. Ee ‘SM loa # REMARKS. q 8 a sos ; a 3 Ss | Dir. |Force. Ho § _ Bancoora ..| 4 A. M. 29°552| 8S. W. 5 | Strong wind and over- ‘e cast. 8 A.M. "639 5. W. 3 | Moderate breeze and fine throughout. Noon | 20° 01’ | 88° 25’ | ‘542; S. W. 3 | Do. * “do. do. 4P.M. 638 Ss. 3 |Current 80 miles ad- verse. 8P.M. 539 8. 3 | Moderate breeze and fine. Midnt. 552 Ss. 3 | Moderate and fine at | Saugor. Star of Al- |4 a.m. 29°540 Gale moderating, wea- | bion .., |8a.mM. ‘570 ther finer and less 4 Noon {{20° 15’ | 87° 28’ | °610/8.S.W. | 6to4| sea. . 4.P.M. 620 S. 8 P.M. 670 Latter part much finer. Midnt. ‘670 Saint Mag-/44.M. 29°440|S.S.W.| 8 | Squally rainy weather, ¥ heavy sea. 4 490) 8:5. Wo) e 7 (Do, do: do. 20° 32’ | 87° 56’ | -470|S.S.W.| 6 | Strong breeze, cloudy hazy weather. 490 8. 5 | Cloudy rainy weather, nasty sea. °570| ~=S. 4 | Moderate and fine. 29°450|} S. W. 5 | Weather having a much finer look, and 20° 50’ "500 4 barometer rising, are proofs that the strong 20° 32’ | ‘87° 34’ | +430 3 winds are now over. *580 1 A very strong wester- 620 1 ly current. *680 29°490| 8S. W. 6 |A. M. Strong breeze, sea going down. F, 8 A.M 540 ve 6 Noon | 20° 83’ | 88° 81’ | *540 i 5 | Noon. Moderate breeze and clear. P 4P.M 520 5 | 3-45 p. mM. Passed EK. Channel Light Vessel, ? 8P.M “580 ee 5 |8 p.m. Anchored in Saugor Roads. Midnt ‘600 ss | 5 ) 14 102 J. Eliot—The South-West Monsoon Storms [No. 2, oo . 3 & He Wind. Soke [ge Vessel. | Hour.| 6% lero & é REMARKS. 3 5 B38 : Dir ° 8 Hi Es & AS British 4 .M. 9 | Squally with rain. Princess | 8 A. M. 9 | Sea very high. Noon | 20° 33’ | 88° 19’ 8 | Sea very high. 4P.M 8 8 P.M 6 | Sea very high. Midnt 5 | High confused sea. Prince 4A.M. S.8.W.| 10 | Midnight. Gale break- Amadeo | Noon | 20° 39’ | 88° 20’ |29°530|_ iS... 8 ing. 8P.M 5 |4 a.m. Strong S. S. Midnt 5 W., occasional heavy squalls. Noon. Strong wind §S., weather finer. Commillah | 4 a.m. 29°349| S. W 9 | a. M. Hard squalls and 8 A.M. "423 |8. 8. W. 8 heavy rain and high Noon °434| 8.8. W. sy sea, stood to south- 4P.M. 401) 8. W. 5 ward. A very high 8 P.M. 464) Var. 4 sea running from Midnt. 569 | E. 8. E. 3 S. W. 54.m. Stood up to Northward. Weather clearing at times for observa- tions. 8 A.M. Hard squalls from 8. W. and high sea. Noon. Overcast, weather hazy. 4p. M. Fine weather. The preceding observations call for little remark. They show that south-westerly winds were fully established over the whole of the north of the Bay, but that they were diminishing rapidly in force. Before sunset, moderate breezes and finer weather had set in. Heavy squalls — came up during the early part of the day, but the only vessel which re- ports rain during the afternoon was the Saint Magnus. In her case, however, it is stated that the weather improved rapidly and was fine, with moderate winds, at 8 p.m. Hence, the stormy weather in the Bay ceased about noon of the 30th. A heavy swell continued to run for some little time afterwards, and strong westerly winds prevailed for the next 24 hours. July 1st.—The following table gives the observations taken at a few of the most important stations, and indicates the general character of the weather over India on the morning of the lst :— 5 i ¥ zo) x 4 ys j Li ‘ . Bengal. _ over Bombay and the south of the Peninsula. Strong west winds pre- | of the Bay of Bengal in 1883. 103 o°o oO 2 2 ; iy ties Wind. 4.25 a 9 o 6 gq |e oe: 2 ey Amount in/o . eit 4 BSP | o miles per = = 29 e Weather. g j= = sy, | Direction. hour since | <|= 848 3.8 | S49 | 104. uw. 10 a.M.pre-|§ 3.8 & 2 Ate oO viousday.|O | Ass GE, EY Cee lela 29°676 | + ‘121 S. E. 7 8 | 0°29 | Fine. 566 | —‘070 | E. N. E. 8 10) ... | Strong wind. 701 | + °212 N. 3 8 | 0°77 | Dark, gloomy. 642 | + 057 | W. 8S. W 17 9 | O17 | Sultry. 765 | —:010 W. 17 10 | 0°21 | Showery. 678 | + °032 N. 5 7 | 0°74 | Showery. 471 | —°203 W. 11 10 | 4°08 | Continuous rain, 775 | —:‘038 W. 8 Cpe... || Hine. 803 | — ‘042 BW. tH Bepiciv. 1 Mime: The observations of the lst indicate that the barometric depression moved during that day in the same direction as hitherto and at a rate of about 15 miles per hour. The westward motion of the depression had caused. a fall of nearly two-tenths of an inch in the barometer over the greater part of the Central Provinces, and a general, although a slight, decrease over the whole of the Peninsula and Bombay. In Bengal, the rapid recovery in progress on the 30th continued. A rapid rise had also occurred over the Punjab and the western districts of the North Western Provinces, due to some other and independent action. A very distinct circulation of the air was shown round the centre of depression. In the mid-Gangetic valley, the winds had drawn round to north-east, and, over the western portions of the Central Provinces, they were blowing from north-west. Moderately strong winds continued at the Head of the Bay and in South No change of importance had occurred in the wind directions vailed along the Bombay coast, where, however, little or no rain was falling. Local winds obtained in the Punjab. The sky was less clouded, the weather finer, and rainfall less in amount over the Gangetic delta and valley. The depression was, however, giving very heavy rain to the Central Provinces, where the sky was overcast. Over the remainder of the country, the weather was of the usual monsoon character. The storm had advanced through the Chhatisgarh division of the Central Provinces (which includes the Sambalpore, Bilaspore, and Raipore districts), and was now passing through the Jubbulpore and Nagpur divisions. The following table gives the 10 A. m. observations at the stations in the neighbourhood of the centre at that hour :— 104 J. Eliot—The South-West Monsoon Storms [No. 2, oo Oo nm ,_» ©-.! pod ve ae Wind. 2 ("By rns a >) E B are g i oe. fe 4 Amount in| 2 @ 9 Weath TATION, + 2°9 me a= miles per | 2 2 oe eather. Fo | Ss ‘< hour since |~ 4/8 3° a=s | Sia Het |l0a.M.pre-|6 5 )-4 4.8 Adals Ag |viousday. |O |e ————— 7 oe Sambalpore ... | 29°526 | + °173 a. Wis 1°4; 6 | 1°84 Raipore:..c. ive. 535 | + °024 S. W. 20°0 10 | ... | Overcast. Hazaribagh ... “627 | +109 | E.S. E. 20°0 8 | 0°34 | Gale of wind. WRB ws Sccvas vase "5384 | —*090 EK. 21°0 10 | 0°08 Ditto. PROGMI io. nalvd@ade "463 | —°202 | N. N. W. 150 10 | 4°60 | Continuous rain. Jubbulpore ... "483 | —‘204| N.N.E. | 80 10 | 1°82 | Moist & mug- gy. Nagpur ...... *A71 | — ‘203 W. 110 10 | 4°08 The number of observatories in Chutia Nagpore and the north- eastern districts of the Central Provinces is very small for their extent. Hence, it is not possible to state with approximate exactness the position of the centre of the depression at this time. The observations, however, indicate that the centre was to the east of Seoni, and that it was at nearly equal distances from Jubbulpore, Seoni, and Nagpore, and hence almost certainly in Lat. 22° N. and Long. 81° E. | The following table gives the observations at 4 Pp. m. for the deter- mination of the position of the centre at that hour :— sg | 75 5 2 Oo H ° STATION. q ae i | a a a i. 38 ais te Weather. ae rea le See: | e.s(s..| Se | 68,5 [Ba Ba? Onmbp + 45 g'd BS loa a a0 As Shen 1D RPE none aes 29°355 | —-191 We 11°7 | 10 | Overcast. FiRIpOFE’?. 2 s.. ek. >e ‘415|}— 0 Ss. W 64°1 | 10 | Overcast. Bare. t or eines 323 | — ‘220 EK. 972 | 10 | Overcast, raining. PNB. ois nc eee 435 | —-°098 E. 30°0 7 Jubbulpore ...... 375 | —'163 | H.N.E. 142 | 10 | Gloomy. BBMAOT. .:. ocReal ‘412 | —‘178| N.W. 2°3 8 Hoshangabad ... *420 | —°153 | W.S. W. 2°8 | 10 | Overcast. Khandwa ......... "478 | —‘132 | W.N. W. 20°71 | 10 | Raining. BOL Ae i wes hands. 509 | — ‘091 | W. N. W. 21:0 | 10 | Overcast. Dito. satan 533 | —°073 | W.N. W. 15°0 | 10 | Overcast. a el 1884.) Allowing for the amount of the fall of the barometer between 10 a. M. and 4 p. M. due to the diurnal oscillation, the barometer had risen at Sambalpore ‘11’, and had also risen at Akola ‘02”. The only portion of the area in which it had fallen was that represented by the station of - Seoni, where it had fallen -03”. of the Bay of Bengal in 1883. 105 The wind directions at Seoni and Nagpore were east and west respectively, and indicate that the centre was between these two stations, and probably some little distance to the east of the line joining them. _ Its probable position was hence in Lat. 22° N. and Long. 79° 4.5’ E. The following table gives the average rainfall during the previous _ 24 hours in every district of Orissa and the Central Provinces :— | : Average : , Division. District. rainfall of ee ae district. uaa PGORBO: hil cdeeb toeuna tie 0.01 0.05 MEMATISED oss ccecscccsasescecee Siri 0 spyereeneennty Me Re nil. nil. y Balasore: lac sss Guzerat at 10 a. M. are given below. They shew that the whirl was still quite distinctly marked, that it continued to advance to the westward, and that it was now near the Head of the Arabian Sea, to the 8. W. of Kurrachee. A rapid rise of the barometer had occurred over upper Sind and Guzerat. Kurrachee was the only station where pressure was lower than on the morning of the 3rd. South-westerly winds prevailed in Cutch and Guzerat. The wind had shifted round to east at Kurrachee, and was blowing with considerable force. It brought up a dust-storm _ from the Rajputana desert followed by rain. The centre of the depression had crossed the Sind coast during the _ previous evening. It is not possible to follow its motion further, as no observations are available for this portion of its path. It is, however, | j probable that it speedily broke up. The following 10 A. Mm. observations taken at stations in Western India nearest the area of cyclonic disturbance illustrate the previous remarks. i i : | : Wind. | . : ° 3 8 Ns, = ae are qe a 46 n o°O os 7 + ond = a oS na dh @oLlA ms SratTIon ba =a S 7 aries So ee Weath 7 od ap q > or Rg g BS op a er. | $6 8_: o & on fa, .| 2.5 ¢ Bo OO SA |6.9 24 big S| 2S Wb ds ‘evga | Ho) ne} [ 6.| 297195 Thunder. Midnight. Wind and weather the same. Barometer still falling, every appearance of heavy wea- ther. Thunder and lightning all round the horizon. 1 |W.N.W.| 6 | 29°148 Commences with dirty and very threatening weather. Lightning 2|N.N. EJ 6 | 29°070 Raining. all round the horizon. A very heavy sea running from 8. E. 3 se 6 | 29°094 Winds variable. L 5 | 29°074 Thunder. 5 IN. N. W.|5to6) 29°112 6 bes 6 | 29°126 Squally. 7 6 29'138 128 [No. 2, Wind. g\4 F ge @ | 6 2 a6 Weather. REMARKS. Al 2 o = 5 Renee | ae ° mH Bide. 8 W. 6 | 29°120 Squally 8 A. M. Wind and weather the same, but sea increasing. Wind 9 29°122 shifting all round the compass, from west through south and 10 |S.8.E.| 3 | 29°140 Squally. east, accompanied with terrific rain squalls. 11 29°086 . | 12 |E.N.E.| 7 | 28-998 Raining. Noon. Blowing a furious gale with oD : 2 terrific heavy squalls. Sea still mi increasing and barometer falling. @ | 13 IN. N.W.| 8 | 28'989 Raining. ety a W. 8 | 29°068 Raining. Pe eo ee 8 | 29°088 Raining. tee?) Bae | 8) 20 Tie Raining. 4 Pp. M. Wind and weather the i same. 17 |8.8.W.| 9] 29°184 Raining. 18 | S. W. 9 | 29°184 Raining. 19 |S.S.W.| 9 | 29°164 Raining. 20 a 9 | 29°247 Raining. 8 p. mM. Wind and weather the same. 21 |S.S. W.| 9 | 29°288 Raining. 22 ie 9 | 29°306 Raining. 23 = 9 | 29°320 Raining. 24, ea 9 | 29°326 Raining. Midnight. Weather more moderate, less wind and sea. 1|S.8.W.| 7 | 29°324 Raining. Commences with moderate gale and high sea but better appearance in the weather. shi x 7 | 29°336 Raining. 2 | 3 ‘ 7 | 29°346 Raining. r| 4 “5 7 | 29°353 Raining. s 5 on 7 | 29°356 Raining. eat. O ys 7 | 29°361 Overcast. Ss 7 8. 8 | 29°365 Overcast. ee 8 > 8 | 29°415 Raining. 8 a. M. Observed a large circle s round the sun. oc) 9 * 8 | 29°440 Raining. 10 aS 8 | 29°474 Overcast. Lk re 6 | 29°486 Overcast. 12 3 6 | 29°464 Raining. Noon. Strong breezes with blind- J. Kliot—The South-West Monsoon Storms ing rain squalls. Pp. M. Weather fine. Heavy swell from southward. * of the Bay of Bengal in 1883. 129 CHAPTER IV. Tur History or THE Storm or tHE 10TH to 15tH Novemper, 1883. The present storm was generated in the Gulf of Martaban, after the ' north-east monsoon had been established for more than a month over the north and centre of the Bay. The rains of the south-west mon- soon terminated prematurely in Bengal in the last week of September. It is a well-known fact that the commencement of the north-east ~ monsoon on the Coromandel coast is due to the recurvature of the south- | west monsoon winds over the south and centre of the Bay. The lower | atmospheric current, which is from south-west in the extreme south, | at that period changes, through south-east and east in the centre of the J Bay, to north-east on the Madras coast. The south-west monsoon current | of the year 1883 was unusually weak, and, when it retreated from Bengal, it recurved immediately, and north-east winds were established on the Madras coast in the first week of October. Hence the north-east mon- ' soon rains set in over the Madras Presidency a week or ten days earlier than usual. They gave general, and unusually heavy, rainfall, as is shown by the following table of rainfall at eight of the more important stations in that Presidency. Rainfall at eight stations of the Madras Presidency, October 1883. 3. LO ee af 18 bea ee | 1G y 27 Ee | ee ee 1°62} 2°35) 0°10} 0°23) 1°50 0°75) 2°44) ... | 1°47) 0°31 0°10} 0°26} 0°46} 0°63) ... Aver- "Stations.| 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | Total.| age. ee ee ee ee ee ee ee ee ee ee ee _ Cocona- maa... | 0°66) ... 0°90} 0°25] 5°70} 18°31} 8°60 - Masuli- patam 0°28) ... |0°21/ 0°05} 0°01) ... | 0°24) 0°03) ... 0°03} 1°25] 0°70) 4°95) 18°35] 8°58 Madras | 0°16 0°10) 0°12 0°37) ... ~ Salem... Poi... Ost «0s 0°02) 0°16) 2°89} 2°12) 1°54) ... 0°40] 0°35] ... 0-96| 12°44! 7-22 A nd ee Look. Punk | cee | coe | vee [OUR] 3. | 2°55} 8°20] 3°00) 24°40} 9°84 Madura 0°41) .., |O°O7| ... | 0°50) ... | 1°35) ... | 0°25) 0°12) ... | ... |0°20| 8:98) 888 _ Trichi- | nopoly| ... | 2°47) ... |0°46) ... | . fell dee pase | OO OeE: he} 0°69} 7°94) 7°86 "Tanjore | 0°08] 0:06) 1°70) ... | ... |... J.» | ... | 0°20] 0°60] ... | 0°05] ... |0°20| 6°86] 5°60 130 J. Eliot—The South-West Monsoon Storms [No. 2,9 Rainfall at eight stations of the Madras Presidency, November 1883. Stations.| 1 ay S44 68) 6) 7) 8) 910) Tie ie ae SS | |) | Ss | | | S| | | | | | Cocona- da.... A ae ee | ee RI cana cect cow tll seca d ede: Longe de utel teers Masuli- parate GE BO 12.20 | de |) ae eee [yy dope ew a eee cadet Vo mes lf ear tines 1h con), helen Madras 1°87 |2°46 |2°12 |1°15 (0°27 |0°12 |0°14. |0°41 |0°02 Salem...| 0°73 |0°94|0°27 |1°16 0°16 ... [0°02 /0°O1 0°75 (0°06) ... |... | ccc | cee | ve Nellore 10D) 1:60 0°45 \0°COM OR IO-OB Fed oh ccas Plea! Pl eee h leay 1 cea Madura | 1°95 /1°80|1°08 |3'00] ... |0°20 0°04 0.03] ... [0°33 |2°00] ... |... |... | cee Trichi- nopoly | ... [0°06 |0°25|1°96] ... | ... [144] ... (0°10 Tanjore | ... |0°27 |0°08 1°78 |1:02 [0°06] ... |0°85 Stations.| 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 125 l26/27I28129!30) Total. | Aer" age. Cocana- da aed tae | w., |. etic sdets 9°97| 3°59 Masuli- patam Ric etcls. | “ge dae peers thas ...| 1485) 411 Madras |... | ... |0°30/4°75 |1°31 re NR os Ai at es Le .| 14°92} 13°40 Salem...| ... | ... (0°25 0°01 Pe wees... eee 4°36| 2°65 Nellore |... | ... 1\0°DS'O°7O =. b... ) er cl Tees|..e|s0e{.] SOO? tee Madura]... |... 0°20) ..., | eeemiO°S5) cond 0 tees .| 10°98] 5°37 Trichi- nopoly | ... {1°26} ... {0°08 0°07 ea ae eee oe 5'22| 5:28 Tanjore | ... |)... |e@@/\@O2Zi017 0'48)'*.. teas 2g Oe be) cel Ba fi 7°63| 5°54 The preceding table shews that rain fell more or less continuously during the whole of October and until the 4th of November, after which a few showers fell until the 9th and 10th, when rain entirely ceased for several days. After the 4th, the north-cast monsoon current decreased of the Bay of Bengal in 1883. 131 November average: 4th. | Sth. | 6th. | 7th. ee — eC eeces=SOOOO eee eee ee 9|SE | 9| ENE | GENE| 9/ENE| 7} NE | 8INNE! 7 6°8;WSW| 5) SE/| 6 SE | 7INNE| 5) N/| 5) N {6 E 56| SW |?|SW| OWNW!/?| NE | ?/|NNE/ 2} NE | 4NNE 6 | || The preceding observations shew that the north-east winds on the Madras coast were diminishing in force. It is, therefore, probable that the south-west monsoon current over the south of the Bay was much weaker, and that, instead of recurving and blowing strongly on the Madras coast, it was continued over the centre of the Bay as light and variable winds. This supposition is, it will be seen, confirmed by the accounts of the weather contained in the logs of the vessels navi- pating the Bay to the west of the Andamans at that time. The cyclone did not commence to form until the 9th of November, but the meteoro- _ logy of the Bay on the 7th and 8th is given to shew the character of the _ weather prior to the storm. 7th November.—The barometer was oscillating at the time slowly over the whole of India, and the distribution of pressure was almost identical with that which had obtained for the previous three or four days, and differed very slightly from the normal. A slightrise of the barome- ter occurred during the previous 24 hours at the great majority of stations. The barometric changes were, however, of no importance. The barometer was highest in Scind and Rajputana, where the readings averaged 30°05”, _ and was lowest over the south of the Bay, where, as shown by the returns of Negapatam, Trincomalee, Port Blair, and Nancowry, it was slightly below 29°95”. The differences of pressure were hence comparatively _ small over the whole area. The following table gives the 10a. M. readings of the barometer, —_ 132 - J. Eliot—The South-West Monsoon Storms [No. 2, reduced to sea level and for temperature, at the more important meteoro- logical stations around the Bay :— Barometer Barometer at 10 a. M. at 10 a. M. ciahal «3 reduced to Sipiaecs. reduced to sea level. sea level. Saugor Island ............ 30°028 | Chittagong ............ 29°994 Palse: Pomt® 3.02.6.0.s00 fe) BO O28 | Bcvaly ooo .sc cash cossenee | eee Gopaulpore ...............| 80°016 | Diamond Island ...... 29°970 ViSRCaPAtaAM ....ic5.....03. wg Old Port Blair. v. .:....2<.5) | eee EGR cho cee ese caches eceses |g OLS "| WaNCOWTY..20.¢.reaecec] ae Negapatam ...,........... | 29°948 | Moulmein ............... | 29°958 Trincomalee .....4..0.060+0) | 4 29 90) | Rangoon ......).0.0.».. | oo Cee Met OT 3. 6. vces sce tno ost) ae The gradients over the Bay were normal in character, pressure de- creasing from north to south. The total barometric difference was slightly less than nine-hundreths of an inch. The average barometric difference between the north and south of the Bay in the middle of November is ‘(075”. The distribution of pressure over the Bay on the 7th was very approximately normal. Over the greater part of India, including the whole of Northern and Central India and the North Deccan, the weather was fine and skies clear. These were clouded in Southern India, more especially on the Coromandel coast, where they were generally overcast. Over the whole of the Indian land area, winds were normal in direction. North- westerly to westerly winds prevailed over the greater part of the Gangetic plain, and northerly winds in the Gangetic Delta. Along and near the Coromandel coast, north-easterly humid winds were giving mode- rate showers of rain. In Burmah, winds varying between east and north-east prevailed. The weather in every part of the Indian area, so far as can be judged from the land observations, was of the usual No- vember, or cold weather, type. There were no signs of the existence of any atmospheric disturbance either in the land or adjacent sea area. The only indications of the probable early occurrence of stormy weather in the Bay were the lghtness and variability of the winds over the centre and south of the Bay, and the rapid and steady decrease in the rainfall of the Madras Presidency. of the Bay of Bengal in 1883. 133 ‘The following table gives the chief observations taken during the day ai the stations subsequently affected by the cyclone :— (ean On nO @w » si a : * 3 _| = — | Wind direction. |S ‘o 5 Be hd a 350 | 25 goF I8 Io wee l| ae aie |8 Jos Stations. g sien aa ae ~ |§ 3/29 | Weather. ee Soa lOa.u. 4p. wl32 a by 1g 8 B42] 85 28 Bb ala ms 69 S fe IS lag acts 29°943 | + 041 Ss 8.S.W 4 6 | 0°62 Sess 29°945 | +003 | S. E. S. E. 4 7 29°970 | + 083 |E.N.E.| &. 5 5 | O11 | Thunder. Sy ee 29°975 | + 027 |E.N.E.| W. 2 irae. ) bine, 29:994 | + °027 | N.N.E.| KE. 2 1 oa. Sane, Peer 29°969 ; + 081 | N. W. | N.W. P 10} ... | Threaten- ing weather eats fi 20°977 | + 037 EK. S. E. 4, 10 | 0°02 | Gloomy. ae 30°004?} + ‘068 | E.N. E.|E.N.E. 3 10 | 0°28 | Cloudy. Te 29°958 | + °073 E. NW 2 9 Cloudy. 1 6 Cloudy. » Mergui ......... 29°956 | + ‘015 NN; Calm The information relating to the state of the weather in the Bay on the 7th of November, contained in the logs of vessels navigating the Bay this period, is given in the following statement :— © H Vessel. Ss Ey ‘ba |S eg REMARKS. ; $ a a ae H S ii#é : 2 Mount Stu- Noon {11° 50’ |91° 50° |29°925 Passing clouds towards noon, heavy rain clouds d 4 P.M. all round, but cleared _" away towards sunset. i . 8 P.M. Weather unsettled- looking. . Midnt. KwangTung/4 A. M. 29°851 bo 8 A. M. ‘909 Fine weather through- * out. Noon |12° 33’| 93° 6’ | 943 z 4 P.M. "921 Sea smooth. ; 8 P.M. ‘909 by Midnt. ‘906 18 134 J. Eliot—The South-West Monsoon Storms [No. 2, Wind. REMARKS. Probable reduced barometer. Dir, Force. < oO a ©, Hour Latitude. N. Longitude Pere aks. 4A.M. Ny a Fine weather and smooth sea. Noon |19° 43’ |88° 15’ |29°980| N. 4 Midnt. N. 4 Parthenope | Noon |20° 10’ |89° 51’ |29°975 N. [Moderate] a. m. Light unsteady breeze, fine, and clear. Midnt. N. W. | Light. | Noon. Wind very un- steady. Current per- ceptible, setting to the S. W.4 p.m. Moderate breeze. 8 P.M. Light 7) breeze and clear, with frequent lightning. Breadalbane| Noon |20° 55’ | 88° 8’ |29°975 |N. N. E.| Otol | Calm and variable airs throughout, current to Ss. W. 4p. M. NE by N| 2 to3 | Sea moderate. No rain. The information respecting the weather in the Bay is very limited, and confined to extracts from the logs of five vessels, and to the observa- tions at Port Blair, Nancowry, the coast stations, and on board the light vessels near the entrance to the Hooghly. Three vessels, the Frank Stafford, Parthenope, and Breadalbane, were near the Head of the Bay. The weather was fine, the sea smooth, and winds light and unsteady. These varied between N. H. and N. W. in direction, and did not exceed force 4 at any time during the day. At Port Blair, the sky, which had been almost clear on the 4th, 5th, and 6th, was clouding over. The air was unusually clear in the morning, but the weather became cloudy and gloomy in the afternoon. No rain fell on this day, nor had any fallen since the 4th. The winds also were extremely light. Only 100°6 miles were registered for the 24 hours preceding 4 p. M., the smallest amount in 24 hours recorded during the month. The sky had been densely clouded at Nancowry for some days past, and rain in moderate amounts had been recorded on every day. On the 6th 62 inch fell with 8. S. W. winds. During the first three days — of the month, the winds were from south-east, the normal direction — of the Bay of Bengal in 1883. 135 in November, when the south-west monsoon is recurving over the centre of the Bay, and giving north-easterly monsoon winds and rain to the Coromandel coast. The amount of wind registered at Nancowry on each day of the first week of the month, is given in the following table :— Total wind! Rainfall at amount of the! 6 Pp. m. of the | Wind direction 24 hours previ-} preceding 24 10 a. M. ous to 4 P. M. | hours. ee 46'7 0°47 S. E. Me i fcc casera vay sncns 38:2 0:21 S. EH. Peace iG. conics. deuces tue 440 2°86 E.S. E. Rs eee 19°5 0-41 S. W. ER ae 18°8 0°96 S. W. EE viinio xi ciesnd vans onneey iy 0°62 S. W. Nk vos cv wi sion ps vive tine 125°4 1:14 S. 8S. W. Average October ...... 149°7 | S. 50° W. | » November ... 1172 | S, 29° H. Se This shows that, in consequences of atmospheric actions, the nature of which can only be conjectured, the air motion over the south of the Bay was unusually and remarkably feeble during the first week of the month. The moist current advancing northward, instead of curving through south-east and east and arriving as north-east winds charged with vapour on the Coromandel coast, was exceedingly weak for some days in the neighbourhood of the Nicobars. It had also shifted in direc- _ tion on the 4th, and was proceeding from the south-west directly into the Martaban Gulf. Rain also began to fall in increasing amounts over - this and the adjacent parts of the Bay. _ The ship Mount Stuart was advancing northwards, a little distance to the west of the Andamans. She was in Lat. 11° 50’ N. and Long. 91° 50’ ' at noon, and during the day had very variable winds commencing from N. E. by N. and ending at S. The weather was fine, but the air was charged with moisture. This is shown by the fact, noted by the Captain, that, during the hotter part of the day, when there is undoubted- ‘ ly much upward movement of the air, heavy rain clouds formed all i around, but cleared away again towards sunset. * The Kwang Tung, on the other hand, was to the east of the Andamans in Lat. 12° 33’ N. and Long. 93° 6’ E. She had fine weather throughout, with light and variable winds during the day of force 2. The wind shifted from S. E. to N. E. and thence to 8. W. during the day, 136 J. Hhiot—The South-West Monsoon Storms [No. 2, | Hence, so far as can be judged from the various meteorological re- | turns, ight winds and fine weather prevailed over the greater part of the Bay. The usual change in the direction or recurvature of the south- — west monsoon current (which gives a feeble cyclonic circulation to the — air over the centre and south of the Bay) was not only much weaker than usual, but was suspended over a part of the area in the neighbour- hood of the Nicobars and Andamans, where very light unsteady winds had prevailed for the previous two or three days. There is, however, no — evidence in the meteorology of this day of the existence of any local cyclonic circulation, such as might form the initial stage in the develop- ment of a cyclonic disturbance or storm. The observations at Moulmein and Mergui confirm the previous statements, and prove the existence of light variable winds, chiefly from the east and north, on the east coast of the Martaban Sea. 8th November.—During the preceding 24 hours, a rapid fall of the barometer had taken place in the Punjab. The amount of the fall was 26” at Mooltan, :13” at Quetta, and’ :12” at Dera Ismail Khan and Lahore. It will be seen from the meteorology of the 9th and 10th that this fall was the first indication of the occurrence of a cold weather or north- east monsoon storm in Upper India. It is during these storms that a large portion of the snowfall of the higher Himalayas takes place. In consequence of this rapid fall, pressure was lowest over the Punjab. Sudden and large changes of pressure are a frequent feature of the cold weather in the Punjab. It is not yet quite certain whether the forma- tion of these Punjab areas of low pressure commences simultaneously over the Western Punjab and the adjacent districts of Afghanistan or Belochistan. This appears to be the most probable explanation, but it is not unlikely that some may occasionally form much further to the west, and pass through Afghanistan or Belochistan into the Punjab or Sind. It will, however, presently be seen that this considerable disturbance in the Punjab exercised no appreciable action on the atmospheric circulation in the Bay of Bengal. The distribution of pressure was somewhat complicated over India itself. Pressure was lowest in the Indus Valley. A broad band of high pressure stretched down the middle of India from Ajmere to Secunder- abad, whilst pressure was approximately uniform over the Bay. The changes of pressure were not accompanied by any immediate marked change in the wind or weather. Skies were clear, and weather fine and dry over all parts of India, except South Burmah and Southern India (more especially the Coromandel Coast), where skies were overcast and occasional showers continued to be received. The amounts which fell at the various rainfall registering stations were very small. of the Bay of Bengal in 1883. 137 The only alteration in the wind directions that deserves notice occurred at Diamond Island and Akyab, where the wind had shifted round to south-east. This of course indicated the further northward ex ension of the south-west monsoon current which had commenced on the 4th at Nancowry. The following table gives the 10 A. m. reduced barometric readings of the recording stations on the coast of the Bay :— Stations on west coast of the Bay. || Stations on east coast of the Bay. INEEROOWEY= bynictacde sos.) BOOS Barometer Barometer é 10 a. M. : 10 A. M. Stations. reduced to Stations. reduced to sea level. sea level. ie Saugor Island............| 29°977 || Chittagong ............] 29°953 See Point...............| 29°983 || Akyab .............se0. | 29°930 ie Vizagapatam ............ 29°976 Diamond Island ...... 29°930 | UMTS. 5 ccs veesve cee ces 29°983 PLOULMNGIN , cs osc eomeches 29°928 | Negapatam ............... 29°978 Port Blair ¢.i3.44..4% 29°936 | 4 The differences of pressure along the west coast were much smaller than on the 7th, and pressure was very approximately uniform. It was slightly lower at the east coast stations, but, even there, the differences were extremely small. The following table gives the 10 a.m. observations at stations in the neighbourhood of the area in which the storm was generated :— at 3 |os dua ie loud 22 |22 || winadirection. (7 22 S18 |S 5 wae [PSS pe iejeee: Stations. [fF .5 |, 7° 8 go 3\@ “\3 S| Weather. | p< 3'o/m~ 314 c SB Poel |e wp } QE 5|go¢ [04M 4m ee eee ele a2 | S S fea ale “ia - ie) ie) ™ Nancowry...... 29°922 |— 021) S. W. 7 10 | 1:14 = ort Blair...... 29°936 |— ‘009/W. S. W./W. S 5 9 | 018 ; Diamond Island| 29°930 |— ‘040| EH. 8. E. 8 13 10 | 2°35 | Thunder. Me Akyab ......... 29°930 |—-045| 8.8. B.| ? 2 6 | 016 - Chittagong ...| 29°953 |— ‘041; N. |E.S. EH. 1 vo ea ) oungoo ...... 29°980 |+ 011) S.W..| S.E. | ? pe a) Bassein ......... 29°941 |— ‘036, §S. EH. |8.S.E. 4 10 |} 0°10 = ‘Rangoon ....... 29°965 |— 039} KH. S.S. K. 2 10 | 0°41 | Showery. io Moulmein ...... 29°928 |— 080} S. HK. N. W. 2 7 ... | Thunder. > Mergui ......... 29965 |+ -009| EE. S. 2 |10| 0-25 138 J. Eliot—The South-West Monsoon Storms [No. 2, The information relating to the meteorology of the Bay on the 8th | is given in the following table :— s |% . 5 Winds. Vessels. |Hour.| %,- ‘be [os & REMARKS. 2A FE is oo : = 5 |23%| Dir. | Force. J — ne oA Mount Stuart/4 A.M. S. to W.| 2to3 | Sea smooth. Passing showers during day. Noon |12° 17/92° 00’|29°925 1 to 2 Heavy black clouds all round, with mo- 4P.M. W toSE. 1 mentary puffs from N. W., and smart Midnt. W toNW| 2 to4 showers towards mid- night. There was lightning in the N. W. during the morning. Midnight. Weather was a little squally. Scottish Hill | Noon |12° 31°/89° 25/29°920| E. to W. 1 | Light airs and calms. 4P.M. O | Wind very variable. 8 P.M. 0 | Sky dull lead colour. Midnt. 29°900 1 Kwang Tung /|4A.M. 29°901| N. W. 2 8 A.M. 19926) N. W. 2 Noon [15° 11/] 92° 6’| °893) N. W. 2 | Smooth sea. 4P.M ‘901| N. W. | 4 tod 8 P.M. °871| N. W. do Midnt "903; N. W. do Frank Staf- |44.M. NW by N 2 | Fine weather, smooth ford. sea. 8 A.M. North. 2 | Very sharp lightning Noon |20° 16’/90° 28’|29'975 IN. N. W. 2 in the S. E. during 8 P.M. oN, W. 1 the night. Midnt. N. N. W. 0 Breadalbane | Noon |21° 00’/88° 18’|29°975| N. Sunrise. Moderate , breeze from N., dying away in the afternoon to a calm. Parthenope | Noon | 21° 2’ |88° 52/29:975| N.W. | gentle. | a. m. Light breeze, Midnt. N. by E. fine and clear. 8 A. M. Moderate breeze and hazy. Noon. Less wind, current setting west. 4 Pp. M. Light airs. 8 p. M. Calm. Midnight. Gentle breeze and clear. a wd By Oca ‘ i ; Sane : » « * . all * y of the Bay of Bengal in 1883. 139 The Nancowry returns prove that the south-west winds in the neigh- -bouring part of the Bay began to increase in strength. The sky was overcast during the day, and 1:14 inches of rain were registered for the 24 hours preceding 1 p.m. The wind during the previous night had shifted round to W. 8S. W. at Port Blair, and blew steadily during the day, _and somewhat more strongly than on either of the previous two days. The _ sky had clouded over, and rain in small amounts began to fall. 18 inch _ was recorded at 4 Pp. M. The weather was slightly disturbed in South Burmah. Passing _ showers fell during the day, and thunderstorms occurred in one or two cases. LEast-south-east winds set in at Diamond Island and at Rangoon. In the interior of Burmah, winds were not so steady as they had been previously. The sky was overcast at Mergui, winds were light and variable, and veered from east to south during the day. The prevalence of S. W. winds at Port Blair and Nancowry, and of _ K.and §S. E. winds at the Burmah stations, shews that there was on this day no well-defined cyclonic circulation, or centre of large disturbance, in the Martaban Gulf. The logs of the vessels in the Bay for the day indicate that similar conditions obtained to those of the preceding day. The Frank Stafford, Parthenope, and Breadalbane were at the Head _ of the Bay near the entrance to the Hooghly. They experienced fine weather, light winds and calms, and a smooth sea. The Kwang Tung had steamed to the north-west during the previous 24 hours, and was in Lat. 15° 11’ N. and Long. 92° 6’ E. at noon. Her log shows that there was no perceptible current in this part of the Bay at this time, an almost conclusive proof of the absence of any strong atmospheric cyclonic circulation in the neighbourhood. The ships Mount Stuart and _ Scottish Hill were a little to the west of the Andamans. The former was in Lat. 12° 17’ N. and Long. 92° H. Her log states that the sea was smooth, but that the weather was becoming unsettled. She began to experience puffs or slight squalls from the north-west. The sky _ during the day was covered with dense black clouds, and occasional showers fell, which became heavier and “smarter” as the day advanced. The winds were very variable, veering from 8. through W. thence to S. H. and back to W. and N. W. The log of the Scottish Hill, which was about 180 miles to the west of the Mount Stuart, gives similar informa- tion. The winds were very light and variable, veering round the compass, the sky was heavily clouded, and the weather dull and gloomy. Hence the various observations indicate the continuance and slight . development of the conditions which, according to our experience of the meteorology of the Bay, precede the formation of cyclonic storms. On the other hand, they give no evidence of the existence at this time of a 140 J. Ehiot—The South-West Monsoon Storms [No. 2, — cyclonic circulation in the Martaban Gulf. South-westerly winds were increasing in force over the south-east of the Bay, and were being con- tinued much further north than is usual in the month of November. To the west of the Andamans, winds were exceedingly light and variable, and such as to show that the south-west winds advancing north- wards were not being continued in that direction near the earth’s surface. The clouding over of the sky, the commencement of showers increasing in intensity and accompanied with slight squalls, indicate clearly that ascensional movement on a large scale was commencing over that area, and giving rise to its usual result when it is partly fed and maintained by a moist current, namely, rainfall increasing in intensity, which, by a known law of rainfall, tends to become concentrated over a limited area. 9th November.—There are no new features of interest in the mete- orology of the Indian land area. Pressure continued to give way in all parts of India. The decrease was greatest in Sind, Rajputana, and the Punjab. The area of barometric depression over the Indus valley was now very distinctly marked. It had as yet exercised no marked influence in the weather of Upper India. The winds were, however, drawing round in the Punjab and neighbouring districts, and indicated a feeble cyclonic air circulation over Upper India. The ascensional movement which necessarily accompanied it, had not given rise to the formation of cloud, except over the North-Western Himalayas. Over the whole of Bengal and the North-Western and Central Pro- vinces, the air motion was very slight, averaging only 1 to 2 miles per hour. In Southern India the weather conditions were unchanged. Cloudy skies continued in the Madras Presidency, and a few occasional showers of no importance were received. The observations at the coast stations of the Bay of Bengal present the same features as hitherto. The baric gradients were apparently normal in direction, but somewhat smaller than usual, and the differences of pressure comparatively small. The most important feature was the weakness of the north-easterly winds on the Coromandel coast. This is shown by the following statement :— Amount of wind Average daily in miles per hour, amount of wind Rinisone. since 10 a. M. | (miles per hour) previous day. | in November. Vizagapatam .....0.cscsncerecsersoveseses ses 2 2°5 Masilipatam ......2nnwdaa spain chan tenets te 2 6°0 MBATAS ” oca..nn cov nus sectteseheeanat teens ane nan 5) 6°38 Negapatam sa AOE 3 5°6 Prichinepoly ... ..021..04. silenanenee Oe enen 1 46 Madduri... . i203. 3 4°] GM AAs ieee ee: C4 Se Lee — _ Meee fw ee ‘ . he | , 4 : : f 1884.) of the Bay of Bengal in 1883. 141 ; The information respecting the weather in the Bay is as hitherto ‘meagre. The following are the observations taken at the land observatories in _ the neighbourhood of the cyclonic disturbance :— ar F. 7 aig 5 Wind direction. 8 ve =| a Sig | ee. | —____|bys alg | Stations. [4$ as od > Bates Weather a 4o4 a<¢7 10 a.m.| 4P. mM SS Selon 2268) £28 Pa Ese oa a a) oO Nancowry ...... 29°897 | —°025 | S. W. S. W. 8 Port Blair...... 29°894 | —-042 W. = |W.S. W. 7 Gloomy. Diamond Island| 29°900 | —:‘030 | E.S.E.|E.S. E. 10 Fine. Chittagong ...| 29°921 | — ‘032 | E.N.EH.|N. N. W. 1 Fine. Tounghoo ...... 29°873?| —:107?| N. W. | N. W. ? Thunder 3 storm Bassein ......... 29°924 | —‘017 |E.S8.H.| S.E. 5 Gloomy Rangoon ...... 29°942 | —‘023 | E.8. E./S. 8. EH. dt: Showery Moulmein ...... 29:898 | —'030 | N. KE. |E.S. E. 2 Showery Srereui ........3 29:995?} + -030?/S. S. H./S.S. EH. 2 Gloomy The Nancowry returns shew that a fall of ‘03’ had occurred in the barometer. The winds were slightly stronger, but were only blowing with an average velocity of 8 miles per hour, the normal rate at that station in November. The sky was overcast, and rain continued to fall in moderate amounts. 2°02 inches were registered for the 24 hours pre- ceding 10 a. m. Heavy rain was apparently falling at this time to the north-east of the Nicobars and to the east of the Andamans. There is no direct evidence of this statement. The first indications, however, of cyclonic motion are presented by the Port Blair observations of this day. The barometer was falling at that station, the sky was, as on the 8th, densely clouded, and heavy rain began to fall in the afternoon and evening. The wind shifted - round to west at 104. m.andto W.S. W.at4 p.m. On the opposite 7 coast of the Martaban Gulf, the sky was overcast, but little rain fell. In , South Burmah, the weather was fine with passing clouds, which gave occasional showers. The sea was slight at Diamond Island. Hence the evidence is fairly complete that there was, as on the 8th, no definite cyclonic circulation, although there were slight indications of its commencement. The shift of wind at Port Blair, and the occurrence of rainfall with squalls to the west of it, render it almost certain that the usual actions, which initiate the formation of an atmospheric whirl on a large scale, were now commencing. The meteorology of the 10th will show that the formation probably proceeded slowly during the afternoon and night ef the 9th, but afterwards with increasing rapidity. 19 142 J. Eliot—The South-West Monsoon Storms [No. 2, | The meteorological information relating to the weather in the Bay of Bengal on the 9th, extracted from the logs of vessels, is tabulated below :— 3 < i E Winds. Vessel. Hour. z tic = ro 8 REMARKS. 3 5 |£36!. Dir Force 4 | Bro Ff — Scottish Hill | Noon | 18° 1’ !89° 42’29°920| N. W. 1 | Light airs and calms. 4.P.M. . 0 | Very sultry, clouds in light masses. 8 P.M. NN. W: O | Sky dull lead colour. Midnt. “B90; ~~“ W. 2 Mount Stuart} Noon | 18° 8’ | 92° 2’ |29°875 O |Sky overcast with heavy clouds all 8 P.M. N.E. | 1t03 round. Weather un- settled. There was — Midnt. HK. 8. E.; 1 to 2 a good deal of light- ning in the sky this morning and towards midnight, mostly in the N. W. Midnight. Weather showery. Kwang Tung /4 A. M. 29°924| N. EH. 5 8 A.M. O41). OT. Hi. 5 | Current during the 24 Noon |17° 37/190° 20'| -936| N. E. 5 | hours, 8.12°E.15 miles, 4P.M. *883| N. E. 5 | Sea smooth. 8 P.M. -856| N. 5 Midnt. 891] N. HE. 5 Satara ...... Noon | Anchojred [{29°950} E. by N. 2 | Light breeze and fine at Go}paul- clear weather. 4P.M.| pore|Roads.| °840 1 | Light airs and fine. 8 P.M. *880 avd 1 Midnt. ‘870 |N Eby E 3 | Gentle breeze and fine. — Frank Staf- |4A.M. 2 2 ford. 8 A.M. i 2 | Fine and smooth sea. Noon |21° 03’|90° 10’|29°935 0 4P.M. ri 2 Parthenope | Noon| Nearjthe |29°930;} N. |Moderate| a. m. Light breeze Sand) heads. and clear. Noon. Moderate breeze and | hazy. Breadalbane | Noon | Near|the |29°935 N. Calms and light airs © Sand) heads. from north through- out. 4PM. N. 1 | Sea smooth and smart showers in the latter 8 P.M. Calm. 0 part of the day. of the Bay of Bengal in 1883. 143 _ The Parthenope and Breadalbane, near the Sand Heads, had light airs and calms during the day. The ship Frank Stafford (in Lat. 21° 3’ N. Long. 90° 10’ E.) experienced gentle northerly winds with fine weather and a smooth sea. The 8. 8. Kwang Tung had advanced 200 miles to the N. W., and _ was at noon in Lat. 17° 37’ N. and Long. 90° 20’ E. She experienced steady north-east winds of moderate force (5) during the day. The ships Mount Stuart and Scottish Hill were proceeding very slowly up the Bay, and had only made about 50 miles during the 24 hours preceding noon. The former was in Lat. 13° 8’ N. and Long. 92° 2’ E., and ex- _perienced similar weather to that of the preceding day. The sea was smooth as hitherto. The sky was covered with dense clouds, and heavy _ showers fell, more especially in the afternoon. The Scottish Hill was in _ the same latitude, but 160 miles further to the west. She had calms during the greater part of the day. The weather was very sultry. The air was apparently almost saturated with moisture. The sky was covered with clouds, and had an ominous appearance suggestive of bad weather. | The observations of the 9th shew that no atmospheric whirl had been initiated as yet in the Gulf of Martaban. Several of the con- ditions necessary for the formation of a cyclonic disturbance were pre- sent. Winds were light and variable over a considerable portion of the Bay. A strong humid current was advancing over the south of the Bay into the Gulf of Martaban, and was giving moderately heavy rain in the neighbourhood of the Andamans and Nicobars. The rainfall had hitherto been too diffused to initiate a large cyclonic disturbance. It _ was, however, increasing in amount, and becoming more concentrated in character, the one additional condition now apparently required for the establishment of a large atmospheric whirl. -—«:10th November.—During the previous 24 hours, a further barome- trie fall occurred throughout the greater part of India. The fall was not so general ason the 8th and 9th, and was much smaller in amount. _ Pressure was very considerably below the normal over the whole coun- try. The distribution of pressure was generally similar to that which ~ obtained on the morning of the 9th. The area of lowest pressure in- - eluded the south-western districts of the Punjab and Rajputana, over which there was a distinctly marked cyclonic circulation of the air. In the south of the Punjab, cloud had formed toa considerable extent, whilst, in the north-western Himalayas, thunder-storms with rain had oceur- red over the lower ranges, and snow had fallen on the higher ranges. In the North West Provinces, Bengal, the Central Provinces, Central India, Bombay, and the northern districts of Madras, the sky was, as it had been for some time, clear, and the weather fine and settled, but un- aide 144 J. Eliot—The South-West Monsoon Storms [No. 2, usually dry for the season. The sky was clouded on the Madras coast, but rain had now ceased to fall, as is shewn by the data given in the table on p. 130. The winds on the Madras coast were approximately normal in direction, varying between N. and N. N. W., but were unusually weak. Hence the effect of the deflexion of the south-west monsoon cur- rent from its usual course at this time, which had been previously indi- cated by the light winds experienced by the Mount Stuart and Scottish Hill to the west of the Andamans, had now extended across the centre of the Bay to the Coromandel coast, over the whole of which area light unsteady winds were blowing. Pressure was very uniform round the north and west coasts of the Bay, as is shown by the following :— Saugor Island ............ 29°929 | Vizagapatam = ..:.............. 29°957 PAINS POG vesaccesccce.ses0e 2 EO OOL | MBOTAR "5... cee... cote The following table gives the observations at the land stations for the day -— : fe = 8 Wind direction. [6 O-3 |@ |B 2 a3 | 86 Bae |2 [8 eee Lee a! et chm Pi Bias Stations. be he Abas Ss] & 3] Weather. on Oo oc ia + Bic aaa Say | =e] 1lOam.| 4pm. [5 , * alo AIS a4 oom Bike Soy S2OB|BO|z x Rda| S40 gas Olomld aa —Q (@) > >) fom Nancowtry ...... 29°856 | —°041 | S. W. S. W. 8 9 | 1:16 | Showery. Port Blair...... 29°850 | —°044 |N.N.W.|W. N. W. sy, 8 | 0°30 Gloomy. Diamond Island 29°917 + ‘017 | E.S.E.| E.S.E. 12 10 | 0°65 | Gloomy. Chittagong ...| 29:915|—-006| ON. | N. Ww. T4'@ Fine, Tounghoo...... 29°'905?| + °032?| N. W. | N. W. ? 10 | 0°22 | Gloomy. Bassein ......... 29°917 | —°007 | N.E. | S8.S. 4, 10 | 0°18 | Overcast. Rangoon ...... 29'920 | —-022| N.E. | B.S. E. 4 8 | 0°85 | Showery. Moulmein...... 29°871 | —°027 |E.N.E.| S., E. 2 8 ... |Showery Mergui, ...+-,.-: 29°868?} —°127?|H. S. E. E. 1 10 | 0°65 | Gloomy. The preceding observations establish that a considerable fall of the barometer had taken place during the previous 24 hours. The fall — amounted to ‘04’ at Nancowry and Port Blair, ‘03’ at Moulmein, and ~ 02" at Rangoon, and was greatest at Port Blair. Westerly winds of the same average strength as on the 9th had prevailed during the —-:1884.] of the Bay of Bengal in 1883. 145 ‘previous 24 hours at Nancowry. The sky was densely clouded and mode- rate rain was falling. 1:16 inches of rain were registered at 10 a.m. At Port Blair, the wind had shifted round to north-west, but was not as yet blowing strongly. Rain was falling, but the amount registered up to 10 4.m. of the 10th was small. In South Burmah; the sky had become overcast, and the weather gloomy and threatening, more especially at Diamond Island and Toungoo. less rain, however, fell on the Burmah coast than had been received on the previous day. It thus again appears probable, if not certain, that the rainfall was becoming more concentrated over a smaller area than hitherto, a favourable, if not a necessary, condi- tion, according to the condensation theory, for the development of an atmospheric whirl. These observations also show that cyclonic circulation had been initiated, and was now established over the centre and north of the Gulf of Martaban, and the adjacent part of the Bay; and that the central de- pression or centre of disturbance, as determined by the fall of the baro- meter, the amount of rain, and the velocity of the wind, was nearest to Port Blair, and to the east of it. Hence it is evident that, although the conditions for the formation of a whirl had been present for some days, it was only on the 10th that the meteorological observations at the nearest land stations gave clear indications of its existence. The information contained in the meteorological abstracts from the logs of vessels is tabulated below :— Ca eae Winds Vessel. |Hour.| eo | ej Sue REMARKS. + of ao 0 3 & |28%!| pir. | Force Se) |e & Scottish Hill | 4 a.m. N. 1 | Light airs and calms. i A.M. N. EK. 1 | Winds very variable. s. Noon !13° 31'\89° 40’,29°910| N. W. 1 | Light airs and calms. S 4 P.M. WNW 2 | Squally and dirty. z 8 P.M. NN. Bi 3 | Arched rain squalls. 7 Midnt. ‘890| N. W. 3 Mount Stuart} 4. M. N. E. | ltoO |Sea moderate with light westerly swell. 8 A.M. ios 3 to 4 Light fleecy clouds. Lightning in the N.W. ¢ Noon |13° 55’191° 81’|29°865!__... is Towards the after- noon, weather began 4 P.M. sei 4 to be squally. At sunset, sharp squalls 8 P.M. ‘805 vee bee and squally -looking all round. Midnight. Midnt. K.byN.|__... Showery. 146 J. Eliot—The South-West Monsoon Storms [No. 2, 7 a : © 2 Vessel. = o REMARKS. 28 oe Satara ...... _M. 29'870|N. N. E. Fresh breeze and fine. 940) BH. N.E. Moderate breeze & fine. 17° 56/\88° 45’) °890 |NE by E. Fresh breeze and fine throughout. Current during previous 24 hours, north 4 miles. 4 | Moderate breeze and fine. 2 | Light breeze and fine clear weather. 2 |Same wind and weather, Kwang Tung 5 8 A.M *899) oN 4 Noon |20° 00’\88° 49’ °920| N. 38 |Current S. 32° EK. 24 miles. 4P.M. “GD. |..-.2N= 3 | Sea smooth. 8 P.M. 904} Calm. Midnt. °934| Calm. Frank Staf- |4 a.m. NaN. W, 2 | ford. Noon |21° 16189° 20'}29°915 2 | Fine, and smooth sea. | Midnt 2 | Lightning during the | night. Chanda ...... Noon | HughllyRiver|29°910 | E.N. E. 2 | 4P.M. *830| EH. N. EH. 4, 8 P.M. *870| Calm. Midnt. ‘910| E. 2 ; Mahratta ... |4 P.M. | Passing Sau-|29°820 E. 2 | Fine weather. ; gor {Island 8 P.M. “900 0 | Clear sky but slightly Midnt. "920 | N. N.E. 2 hazy. Parthenope | Noon 29°915 N. A.M. Light breeze and hazy weather. 4p.M.|Passin'g Sau- Calm. Pp. M. Wind unsteady gor |Island. with gusts and calms. Midnight. Wind . north and light. 1884.) of the Bay of Bengal in 1883. 147 The observations given in the ships’ logs, although not numerous, confirm the information of the land observations given above. The Frank Stafford and Kwang Tung, north of Lat. 20° N. and near the Head of the Bay, met with light northerly winds or calms and a smooth sea. The Mount Stuart and Scottish Hill were passing very slowly up the Bay at this time. The former was in Lat. 13° 56’ N. and Long 91° 31’ E., and observed several of the evidences of cyclonic formation in its neighbourhood. The area of heavy rainfall, as already noticed, had contracted. This explains the fact mentioned in her log that in the morning there were only a few light clouds in the sky. The weather, however, rapidly changed during the day, and became squally in the after- noon. Sharp squalls were experienced at sunset. The barometer was also falling rather rapidly. Winds were from north, and increased in strength from 1 to 4 during the day, indicating the rapid increase of indraught. The Scottish Hill was 120 miles further to the west, and had winds ranging between N. KH. and N. W. during the day. They were very light and variable during the earlier part of the day, but the weather be- came squally towards the evening, and arched rain squalls passed over the ship at 8 ep. M. The Satara, which was passing from Gopalpore to Rangoon, was in Lat. 17° 56’ N. and Long. 88° 45’ E. at noon. The winds varied during the day between N. N. HE. and E. N. E., but decreased in strength during the afternoon. She experienced light breezes and fine clear weather throughout the day. The Chanda and Marhatta left Saugor in the evening, and had fine weather and a clear sky. Hence, except in the neighbourhood of the Andamans, weather was fine. A definite cyclonic circulation had been established to the east of the Andamans between 10 a. mu. of the 9th and 10 a. m. of the 10th. The area of rainfall had for some time contracted, and the rainfall had intensified over the diminished area. Winds of indraught had hence been established, and were increasing in force. This proceeded slowly at first, but, during the evening of the 10th and morning of the 11th, it went on more rapidly, and there was a perfectly well-defined cyclonic circulation, or large atmospheric whirl, established in that part of the Bay on the morning of the 11th November. 11th November.—During the previous 24 hours the barometer had risen rapidly over Northern and Central India. The increase of pressure was due to the filling up of the depression in the Punjab and neigh- bouring districts. The rise of the barometer at Peshawar and Rawal Pindi was ‘2”. The depression had given a large amount of rain over the Punjab, and stormy weather over the north-west Himalayas, on the higher parts of which much snow had fallen. Amongst the heaviest rain- 148 J. Eliot—The South-West Monsoon Storms [No. 2, falls during the previous 24 hours were the following :—Simla 2°15 inches, Peshawar 1°22 inches, and Rawal Pindi 1°20 inches. The sky was overcast, and the weather unusually cold, in Upper India. The winds over a large part of Northern India continued to in« dicate feeble cyclonic circulation about a centre in the north-eastern dis- tricts of Sind. Over the whole of Bombay (excluding Sind), Bengal, the Central Provinces, and Central India, the weather was fine, skies cloudless, and the winds blowing from the usual quarter. Round the coast of the Bay, from Saugor Island to Madras, the differences of pressure were unusually small. The following statement gives the 10 a. m. reduced readings at the more important stations :— RSBGOr LSLATIG Oo pe spas qe nes ons pve enandncennarsneresss eee Tia 0. OUD © x ce Naei xn pee olson highaiant-oee ate cae oh Sony, eee WW UES DAL, 5 cn ates Hoc chop cn bin'tin's ne vip siein esse ba ee a WI PIEER TS &, « ocxs 10s iets hase nipsenp ene vedenceaacys amet ee eee The winds at the Bengal stations near the Head of the Bay blew from directions between north and north-east, the easterly component being probably due to the cyclonic circulation in the middle of the Bay. They were very light. On the Madras coast, the winds were not only more northerly than usual, but were unusually feeble. The data are given in the following table :— Amount of wind! Daily average in miles per |amountof wind Stations. hour since 10 |(miles per hour) A. M. previous | of November. day. Vizagapatam.....ccccscsssssesseeeeseeeeesenns 1 2°5 Masulipatam ......cccessseeeeecesesenssconans 3 6:0 Madras ...ssscsccccceccscevecsvars ses seecanoes 4) 6°8 Negapatam cicccscssesecceeesereceeeeeeneees 2 56 Salem 2 3°6 Madura 2 Ar Over the Coromandel coast, the weather was fine with passing clouds, and rain had entirely ceased. 1884.) of the Bay of Bengal in 1883. 149 . The following table gives the observations taken at the recording ='9 = 8 Wind direction. | 9 ot a ote 2 os Fe AO |x as, ase | ge Be Bein ho 1B ok eas Stations. 8 ao | ae we 5 am g is RE Weather. a e oO. iar 'O er — n ° g = oe | lam.) 4PM. (8, ~ alg tS ad B48 | gic Bee Bese as = 2) > DS | 29°8386 | —‘020 | S. W. S. W. 12 7 | 2°90 | Fine. 29°760 | — ‘090 iW. N. W.|W. S. W. 8 9 | 3:90 | Overcast and rain. Diamond Island| 29°848 ; — ‘069 | EH. N. H.|H. N. 4H. 12 19 |, dria Chittagong ...| 29918 | + ‘003 | N.E. |W.N.W. 1 3 Fine. Toungoo ...... 29'860 | —°045 | N.W. | N.w. [| ? | 10 Gloomy. Bassein ......... 29°861 | — ‘056 | N.N.E.| N.N.E. 5 | 10] 1:24 | Overcast. Rangoon ...... 29°913 | —‘007 | N. EH. | N.E. 5 9 | 0°04 | Showery. Moulmein ...... 29855 | —016| N. |E.S.E. 2 | 8! 0°03 | Fine. CEE .....0... 29°884 | + 016 | E.S. H. K. 3 | 10] 1°30 | Overcast. These observations show that the barometer had fallen considerably at Port Blair, and to a less extent at Nancowry and Diamond Island. The cause of this is also evident from the observations. Heavy rain had fallen at Port Blair and the neighbourhood. Port Blair registered 3-9 inches at 10 a.m., Nancowry 2°90 inches, and Diamond Island 1:12 inches. The rainfall on the Burmese coast was smaller than on the previous day. Hence the evidence indicates that the rainfall was more concen- trated than hitherto, and was falling mainly over an area near to and including Port Blair. This is confirmed by the fact that cyclonic cir- culation of the air was now fully established. Winds were 8. W. at Nan- cowry, HE. 8S. H.at Mergui, EH. N. H. at Diamond Island, and W. N. W. at Port Blair. They were increasing in force rapidly, but were as yet of moderate strength. The wind directions indicate that the centre of the cyclonic circulation was to the east-north-east of Port Blair. It is not possible to infer its position with any approach to exactness from the _ observations, but we are probably not far from the truth in placing it in Lat. 13° 30’ N. and Long. 94° 15’ K. As the vessels which have contributed meteorological data were all to the west and north of the Andamans, they only furnish information 20 —— 150 J. Eliot—The South-West Monsoon Storms [No. 2, of the weather in the outer portion of the north-west quadrant of the cyclonic circulation. The following table gives the whole of the information contained in their logs respecting the weather in the Bay on the 11th :— 5 Oe j = 3 | Winds. 3 ao) o2 . Vessel. |Hour.| #2 | ‘ha re) oH REMARKS. 3 § |e S | Dir Force 4 A gS =| | Scottish Hill |4 a.m. Dirty rain squalls. 8 A.M. N. E. 4 | No sea. Noon {14° 08'/90° 33’\29°850| 4 ae rain squalls and hail. 4P.M. N.W. 5 |Cloudy, gloomy sky. 6P.M. Heavy swell from N. E. 8P.M NN. W 2 |Scud from N. KE. and N.N. E. Midnt °870| N 5 | Wind shifting in squalls. Mount Stuart] 4 a.m. E.N.E. | 2to3 |A.M. Moderate in the ' first part of the day 8 A.M. HE. by N. Towards night, a heavy swell from EK. Noon |15° 30’/91° 06’|29°820 |NNEtoE| 3 to 5 by N. Thick heavy rain most of the day. Overcast heavy sky all round, and dark gloomy weather. Bent storm sails at 2 Pp. M. and kept Midnt. N. by W.|Squally.| away south, as wea- ther was looking very bad. Heavy swell from EH. N. E. at midnight. Byculla ...... 4A.M. 29°880| N. EH. Lk Moderate breeze and squally. 8 A. M. Overcast and squally with heavy | rain. | Noon. Moderatebreeze and overcast, with threatening appear- ance and rising sea. 4 P. M. Strong breeze and overcast, Midnt. “740 nS with frequent hard squalls. 8p.m. Strong freshening _ breeze, with hard squalls and rising sea. Midnight. Moderate gale and heavy squalls. 8a.M. ‘890 | E. N. E. as a Noon |16° 00’\91° 10’| *840 42. M. “770 8 P.M. ‘770 of the Bay of Bengal in 1883. 151 Se | Brats & Winds. Hour.| 84 Foe] Bie es REMARKS. Solin a8 3 Dir Fore eT re = ie F - e. 4A.M 29°800| N.E 4. |4A.M. Moderate breeze and overcast sky, 8A.M °850| N.E 5 with passing squalls . of wind. 8 A. M. Noon |16° 35’|92° 09’| *800/H.N. B. 6 Fresh breeze, sky cloudy and overcast. 4P.M ‘740 | E.N. E. 6 Squally appearance. Black bank of clouds 8P.M ~ *800 K. 6 rising to the Kast. ; 104.m A gale of Midnt "780 | E. by N. 6 wind from N. KE. 11.4. mM. Wind moder- ating. Noon. Strong head. wind and moun- tainous sea. Shipping large quantities of water, vessel pitching and rolling. 4 P.M. Strong breeze and heavy sea, with severe squalis of wind, and ‘ incessant rain. 8 P.M. to midnight. Same weather continued. ae Noon. |16°30’?/92° 0’? N..E. | 4to5 | Weather overcast. Bancoora ... | 44. M. 29:902| KH. 2 8 A. M.. "929; N. E 3 Noon |17° 19’\85° 44") -887| N.E 4 |Moderate wind and fine.. 4 P.M. 838) N. N. E. 4. 8 P.M ‘867 |NE.byN. a Midnt.. °840|N.N.E.. 4 Chanda ...... 4.A4.M. 29°830| N. E. 2 | Hazy.. 8 A.M. "920 |N.N. E. 4 Noon |18° 56’/90° 30’| -920' N.N, E. 4 |Current N. 23° EK. 0°5 mile per hour. N. E. to 4:P.M. 750| S. E. 2 8 P.M. ‘770 Variable. 4 |At short intervals, heavy squalls from ! S.E | S. E. to Midnt. ‘770 | E. by 8. 5 | Heavy squalls from the eastward. 152 J. Eliot—The South-West Monsoon Storms [No. 2, s |g |F& Winds A ne he te OP Vessel. |Hour.| 27 | Hiei [So § REMARKS. E 8 Bs q Dir Force A a a Aviat (2380)! Noon /18° 53’|84° 39° N. E. Moderate wind, clear weather. Mahratta ... |4A.M. 29:860| N.N. EH. 4 8 A.M. "920 4 Noon 21° 16’90° 35’, °940 4, | Fine weather, smooth sea, and clear sky 4P.M "800. N. 3 throughout. 8P.M. ‘870 3 Midnt. ‘900 2 The Satara, Byculla, Mount Stuart, and Scottish Hill were now in directions varying between N. N. W. and W.N. W. from the centre and at approximately the same distance, 250 miles. The Satara was in Lat. 16° 35’ N. Long. 92° 9’ E. by account at noon, and proceeding eastwards to Rangoon, LHarly in the morning, the weather was fine with moderate breezes. Occasional squalls of wind passed over the vessel. The weather became rapidly worse after 8 a.m. A heavy and dark bank of clouds appeared in the east, and at 10 a. m.a gale of wind blew from north-east. The sea rose very rapidly. During the afternoon and evening, the vessel experienced strong easterly winds with frequent heavy squalls, incessant rain, and a heavy sea. The Satara was not only approaching the centre, but was crossing its line of motion in front. Hence the very rapid change of weather which she experienced during the afternoon. The Byculla was about 70 miles to the W. 8S. W. of the Satara at noon in Lat. 16’ N. and Long. 91° 10’ EK. Her positions, as obtained by observation and dead reckoning, agree so closely as to show that there was, no strong current in the northern and western quadrants of the cyclone, and hence that the position assigned to the Satara by account is probably approximately correct. The Byculla was advancing in almost the same track as the Satara, and gives a similar account of the weather. The morning began with moderate breezes and occasional squalls. The sky clouded over about 8 a. m., and heavy rain fell. The winds increased in force, and frequent hard squalls passed over the ship. 1884.) of the Bay of Bengal in 1883. 153 The Log of the ship Mount Stuart, which was in Lat. 15° 30’ N. and Long. 91° 6’ E. at noon, states that the sky was overcast, weather dark and gloomy, and so threatening at 2 p. mM. that the Captain changed her course and kept away south. The Scottish Hill was 100 miles to the south- south-west in Lat. 14° 8’ N. and Long. 90° 33’ E. at noon. The sky was overcast, and frequent heavy rain squalls passed over the ship. A heavy swell from the north-east came up during the day. The weather over the north-east of the Bay is described in the logs of the Chanda, Bancoora, and Mahratta. The Bancoora, in Lat. 17° 19' N. and Long. 85° 44! E. at noon, had fine weather and moderate north-easterly winds of force vary- ing from 2 to 4 during the day. The Chanda, in Lat. 18° 56’ N. and Long. 90° 30’ KH. at noon, had fine weather with a hazy at- mosphere, and light to moderate north-east winds. She was proceeding to Rangoon, and steaming directly towards the northern quadrant of the cyclone. Late in the evening, she began to experience squally weather and variable winds. Frequent heavy rain squalls came up from south- east and east after 8 p.m. The Mahratta proceeding from Chittagong to Calcutta, and the light vessels at the entrance to the Hooghly, had fine weather, clear skies, and a smooth sea throughout the whole day. The meteorological data hence shew conclusively that, during the 24: hours preceding 10 a. m. of the 11th, a definite cyclonic circulation of considerable intensity had been established to the west of the Andamans, the centre of which at noon of the 11th was probably in Lat. 13° 30’ N. and Long. 94° 15’ KE. Heavy rain was falling over and near the centre, winds increased considerably in force during the day, the sea rose rapidly, and gave rise to a heavy swell extending to a distance of three or four hundred miles from the centre. The very rapid changes which had been initiated by the cyclonic motion are indicated very clearly by the weather experienced by the Satara., 12th November.—The barometric changes of the preceding 24 hours were irregular. This was in part due to the continuance of unsettled weather in Upper India. The depression which had formed on the 9th | and 10th was filling up, and its existence was chiefly shewn on the _ morning of the 12th by cyclonic circulation of the air in Sind, and the _ adjacent districts of Rajputana. A smaller depression had, however, formed in the south-eastern districts of the Punjab, the centre of which. was at or near Lahore. This was shown by a slight fall of the barome- ter at Lahore and the neighbouring stations. The barometer had con- tinued to rise rapidly over the greater part of the Punjab, Rajputana, and the Central Provinces, and over the whole of Central and Southern India. A rapid fall had occurred in Burmah, and a slight one in Bengal, due to the development and extension of the atmospheric whirl in the neighbourhood of the Andamans. 154 J. Eliot—The South-West Monsoon Storms [No. 2, In Upper India, skies were more or less clouded in the area of the small depression, and rain fell during the day over nearly the whole of the Punjab, and the western distriets of the North Western Provinees. In Bengal, the Central Provinces, Bombay, and Madras, skies were generally clear, weather fine, and winds light. Skies were overcast in Southern Burmah, and rain was generally falling. Over the west coast of the Bay, pressure was remarkably uniform, the isobar of 29°95 being, in fact, almost identical with the coast line. The winds on the Coromandel coast were stronger than they were on the previous day, but were below their normal force. This is shown by the following statement :— Amount of wind in miles per | Daily average Stations. hour since 10 |amount of wind A. M. previous per hour. day. Wika Ga pabate ei. ote. fo. Vales thee sae 2 2°5 Cacomadal Als emaeett e365. ead 6 9°0 Masalipatare -.. gud. veneer s n+ = oe see 5) 6°8 Negapatam 4) 56 oo) eit ie RR, Se aa 2 3°6 pu). ee eee, ae 4, Ar} The following are the observations taken at the stations affected by the cyclonic depression :— oO oO @B no # a) sw = a - 5 Wind direction. | 8 2 ne es) @ oF Sn z | oO ao = ei & : nies ie ort Sy 5 © S58 Stations. 2S o. |) fs “3 | s|e73 .| Weather. on Fl Gung Pos ia .ja op Ss .9 | ws |10a.M.] 4PM. PS Glo AIS 8H SA 8 a. 38 SH RIBOLE & S fa? Saieee > iO |-4 Nancowry ...... 29°884 | + 048 | S. W. | S. W. Z 7 |} 1:91 | Fine. Port, Blair’. ;.... 29°834 | +°074 | W.S.WIW.S.W.| 18 8 | 0°41 | Overcast Diamond Island} 29°659 | —°189 | H.S.E./8. 8. E. 25 10 | 4°58 | Severe gale. Aleve: «acc .2eh 29°887 P N.N.E.|E.N. E. P 10.4... 4S. Chittagong . 29°899 | —°019 | Calm. |N.N. W. 1 6 a) Wiaa, Toungoo ...... 29°885 | + ‘025 | N. W. | N. W. ? 10; ... | Gloomy ‘ weather. Bassein ......... 29°762 | —°099 |E. N. E.|E.S. E. 12 10 | 5°97 | Overcast Rangoon ...... 29°870 | — 043 |E. N. E.| S. E. 6 10 | 0°84 | Showery Moulmein ...... 29°869 | +014 | S. EH. S. E. 3 6 | 0°04 | Clouds low with scud. Mergui ......... | 29936 | + 052 |E. 8. H.)S8. 8. E. 4 |10° 0°50 | Overcast IS A re Ory ee ke | 1884.] of the Bay of Bengal in 1883. 155 The following information relating to the meteorology of the Bay for the 12th is taken from the logs of the vessels named :— Wiuds. Vessel. Hour. duced baro- Latitude N Longitude. E. Probable re- meter. eee es Mount Stuart) 4.4. M. 29°700\N. N. W. 5 Noon |14° 19’'91° 41’| *750/\W. N. W.| 5 to 6 4P.M. N. W. 5 Midnt. N. W. 5 Scottish Hill | 44. . 29-770 IN. N. W. 5 8 A.M. "790 |N. N. W. 4, N. W. to Noon |14° 36’92° 17’. °720|\W.N. W. 10 4P.M. °630 |W. S. W. 10 5 P.M. “660 |W. S. W. Midnt. ‘720 SW by W 8 Byculla ...... 2 A.M. 29.730 | E. N.E. 4A.M. *660 6 A.M. ‘570 8 A.M. 480) N.E. 10 A.M. ‘480 Noon |16° 03’\92° 36’| 410 NE.byN. 2P.M. ‘380, N.N.E. 4 P.M. *380 | N. by E. 6 P.M. 370 | N. by W. REMARKS. A number of small land birds at about sunset. T'hemoon has had alarge ring round it the last few nights. 4a.M. Cloudy and rain squalls. Heavy sea from N.E. 8 a. M. Heavy rain squalls, sky thick and gloomy, heavy sea from N.N. KE. Noon. Shift of wind to N. W. with heavy, fierce squalls. Sky one mass of heavy black clouds, and rain like a black wall to W.N.W. 2p.M. Fierce squalls. Heavy bank of clouds to the N. W. and N. 5 P. M. Weather clear- er, and squalls lighter. Heavy confused sea. Scud in dark masses from N. W. Midnight. Fresh squalls and heavy rain. A.M. Freshening gale with very heavy squalls, blinding rain, and high head sea. Ship labouring hea- vily. 8 A.M. Strong gale with heavy squalls, and high N.E. sea. Shipping water fore and aft. Noon. Wind and sea increasing. Heavy gale, with overcast sky, and _ continual heavy squalls. Ship labouring _heavily, and shipping heavy seas fore and aft. 156 J. Ehot—The South-West Monsoon Storms [No. 2, ® = E E Winds. e.: |S. (oe Vessel. |Hour.} 82 | ‘ha feo REMARKS. 8 S 2 2 3 Dir Force. 4 fit A Byculla ...... 8 P.M. 29°370 |N. N. W. 8 P. M. Heavy gale (Contd.) N. W. to with terrific squalls 10 P.M. °390 |W. N.W. from the North. Midnt. '400| West. Midnight. | Weather moderating. Satara ...... 4Aa.M. 29°710 |NE.by E. A.M. Strong gale from N. E. with heavy sea, ‘660| N. EK. 9 accompanied with heavy squalls of wind, 8 A.M. ‘650 9 and incessant rain. 8 A. M. Hard gale, Noon |16° 30’/93° 30’| °610! E. by N. 9 violent squalls, heavy rain, very thick wea- 4.P.M. 530 9 ther. Noon. Wind and sea continued 8 P.M. 540 9 the same ; heavy rain squalls. 4 Pp. mM. to E.S.E midnight. Strong Midnt. °520| S. HE. 9 gale from H. by N., | Same wind and wea- | ther. Chanda ...... 4 A.M. 29°710 |K. to NE. Morning. Heavy squalls from E.N. E. Sea ris- E.N.E.to ing fast; S. HE. swell 8 A.M. 7 SO! Nk increasing rapidly. Noon. Strong gale Noon /16° 31/|93 °09’| °640| N. E. with high cross sea. Weather having all the appearance of a cyclone. 4P.M. °560| N. EH. Afternoon. Fierce gale and high sea, with hard squalls and heavy rain. Barome- ter falling slowly. 8 P.M. 610 | N.N.E. Evening. Terrific squalls and high sea. 10P.M. "490 Midnt. 560} N.N. W. Cleared up a little, less rain and sea. Bancoora ... |4A.M. 29°798| N. 4 |6 a. mM. Squally ap- pearance to north- 8 A.M. "849 N. 5 ward. Noon |16° 40’\89° 11’| °805 N. 5 |2 Pp. M. Fresh breeze 4P.M. Pain, aie Pee 4 and squally with light 8 P.M. ‘DBLo Po. WM, 4 rain. Heavy sea from Midnt. 849 IN. N. W. 4 EK. and H.N. E. 1884.] of the Bay of Bengal in 1883: 157 go |g |FEg Winds = ee 5 («, | 22 Vessel. |Hour.| £7 | Ha |ScH REMARKS. E 8 28 3 Dir Force we ae TEs & i Loanda ...... Noon |16°45'?'91°46’?| 29°700) HE. N. E. 6 | Heavy rain and sky overcast. ae 4A.M. N.E. |Moderate! Clear weather. 8 A.M. N. EH. | Fresh. Noon |17° 42’,87° 42’ edi ee es Cloudy and confused swell. 4P.M. N. EH. FA Cloudy and heavy S.H. swell. 8 P.M. N. EK. Cloudy and heavy S.E. swell. Midnt. N. H. | Strong. | Overcast and heavy easterly swell. The observations at the land observatories indicate that the depres- sion was to the north of the Andamans on the morning of the 12th. The centre had thus moved in a north-north-west direction since noon of the 1lth. The barometer had risen considerably at Port Blair and Nancowry, and on the east coast of the Martaban Gulf. Strong winds continued at Nancowry and Port Blair, more especially at the latter station. The sky was cloudy at Nancowry, and was still very dark and gloomy at Port Blair. Moderate rain had fallen during the preceding 24 hours at these stations. A very considerable fall of the barometer had occurred in South West Burmah, more especially at Diamond Island and at Bassein. The winds were unusually strong at Diamond Island. The observer at that station reported a severe gale at 10 a.m. Very heavy rain was also falling in South Burmah. Diamond Island registered 4°58 inches at 10 a.m., and Bassein, 5°97 inches. On the Arakan coast, the weather at 10 a. mM. was fine with passing clouds, and light N. N. E. winds. The position of the centre can only be roughly approximated from the land observations. It was evidently to the W. 8S. W. of Diamond Island and at no great distance. The information extracted from the ships’ logs enables us to determine it with approximate accuracy. An examination of the positions of the vessels, as deter- mined by observation and dead reckoning on the 12th and 13th, indicates, that the positions assigned to all the vessels, except the Satara, at noon of the 12th, may be accepted as approximately true. There appears to have been very little current in the western and 21 158 J. Ehot—The South-West Monsoon Storms [No. 2, northern quadrants of the cyclonic area. The only marked current at this time in the Bay was in the eastern quadrant of the storm area, where the winds were strongest. This current was continued northwards along the west coast of Burmah. The Satara, which was nearest the coast, experienced a very strong northerly current, which carried her 171 miles to the northward and westward (N. 13° W.) between noon of the 11th and noon of the 14th. Her probable position at noon of the 12th, so far as can be determined from the wind direction and height of her barometer, was in Lat. 16° 30’ N. and Long. 93° 30’ E. The Byculla, Satara, Loanda, and Chanda were all in the northern quadrant. The Byculla was nearest the centre, which apparently passed a short distance to the east of that steamer, late in the evening (about 8 P.M.) Harly in the morning, she had a gale with very heavy squalls, blinding rain, and a high sea. The weather grew worse as she advanced southwards. At noon, she experienced a heavy gale with continual heavy squalls. The weather was at its worst about 8 p. M., when a heavy gale was blowing with terrific squalls. Her barometer (cor- rected) stood at that hour at 29°37, the lowest reading taken during the storm. The weather began to moderate at midnight, when she had westerly winds, and the storm was passing to the northward. The Chanda also passed to the westward of the storm. She was at least 150 miles from the centre early in the morning of the 12th. At that time, heavy squalls from the H. N. EH. passed over the vessel, and a swell came up from the south-east which increased rapidly. At noon, she had a fierce gale with hard squalls, and heavy rain. The barometer fell slow- ly, and the Captain at 4 p. M. judiciously changed the course of the vessel to the south-west, and thus kept clear of the storm centre. At 8 P. M., the squalls were terrific in force, and the sea very high. The barometer was at its lowest at 10 p. m., when the corrected reading was 29°49. The wind at that hour was hauling from N. N. H. to N.N. W. Shortly after- wards, the weather began to moderate. The Satara was to the north of the centre during the day, and cross- ed from the western to the eastern quadrant. She, consequently, not only experienced the full force of the hurricane, but was carried a con- siderable distance to the northward by the current, and thus involved in it for a much longer time than either of the preceding vessels. arly in the morning, she had a strong gale from the N. H. with heavy squalls, incessant rain, and a high sea. She continued to experience similar weather during the day. The wind, which was from N. H. at 44. M.,, shifted to E. by N. at noon, and to 8. E. at midnight. She was, judging from the unusually small rise of her barometer between 4 Pp. M.and 8 P. M., probably nearest to the centre between 8 P.M. and midnight. Her low- of the Bay of Bengal in 1883: 159 est reading is not given, but when corrected, it probably slightly exceed- ed 29°5. She was about the same distance as the Chanda from the centre The Mount Stuart and Scottish Hill were in the south-west quadrant, but at considerable distances from the centre. The former, which was in Lat. 14° 19' N. and Long. 91° 41’ E. at noon, had winds of force 5 to 6 during the day. The Scottish Hill was nearer to the centre. During the morning, she had cloudy weather with rain squalls, and a heavy sea: Occasional shifts of wind occurred in heavy squalls, which passed over the vessel from the N. W. She was just on the margin of the storm area. The force of the wind varied from 4 to 5. The Captain describes the appearance of the cyclone area crossing to the N. W. in front of his ship as a mass of heavy black cloud and rain. During the remainder of the afternoon, fierce squalls passed over the vessel. The wind was of force 10, and hauled to W.S. W.at4 2: m. The weather moderated a little afterwards, but she continued to have fresh squalls, heavy rain, and’ a high confused sea, during the remainder of the night. The Asia was about 400 miles to the W. N. W. in Lat. 17° 42! and Long. 87° 42’ HE. at noon. She had fresh to strong N. HE. winds during the day, and a heavy swell from the S: HK. The Bancoora was 260: miles to the W. N. W. in Lat. 16°40! N. and Long. 89° 11' FE. She had northerly winds of force 5 until noon, and N. N. W. winds of force 4 during the remainder of the day. The weather had a squally appearance in the morning.. As.she advanced eastward, a heavy swell set in from the HE. and HE. N. E., which increased during the day. The logs of the Bhandara and of the light vessels near the mouth of the Hooghly show that light northerly winds were blowing at the Head of the Bay, and that the weather was fine, sky clear, and sea smooth. A comparison of the position of the vessels at noon with respect to the storm. indicates that the centre was approximately in Lat. 15° 30’ N. and Long. 93° E. at noon. On this supposition, the following were the distances and bearings of the vessels from the storm centre at noon :— Bearing of Distance of eértre of Gentia of Barometer storm. storm. at noon. Se re i a) 90 39°64 BVA. 66 inn tes nbcnstase vie csanseceostesenlf NON. We 45 29°41 MEE cctv bevecete sass vdcovascs dh ous avs N. 79 29°64 BAMATE, Vue cio becwvydseccrsvs cee svesceeve ccs N. KE 75 29°61 PMRIIIN TAL Uh. cs vices bvavch cee see aus ons S. W 85 29°72 Mount Stuart .......cccceccsscecescnses S. Vi 120 29°75 SOMES acs LeeMM cei iiinse chs vende nsscce.) | Wi Ns Wh 260 29°81 ES eM ew tes edi veo ses | Wee Ne WV. 400 P 160 J. Hliot—The South-West. Monsoon Storms [No. 2, 13th November.—The chief feature in the meteorology of India on the 13th was the cyclonic disturbance off the Burmese coast. A rapid rise of the barometer during the preceding 24 hours over the Punjab and Sind, completely obliterated the barometric depression in that area. Pressure was highest over the Indus valley, where it slightly exceeded 30°15". The barometer had also risen in the Central Provinces, Bombay, and Madras, but had decreased in Bengal and Arakan. Hence pressure diminished from west to east, and was lowest at Diamond Island, where it was 29°826”. The large depression off the Burmese coast was very distinctly marked- Winds were blowing a southerly gale in the Gulf of Martaban. They were easterly at Akyab, northerly in Bengal and on the Ganjam and Madras coasts, thus establishing general cyclonic circulation over the Bay. Elsewhere the winds were generally from the eastward, except in the Indus valley, where they were northerly. The sky was dull and cloudy in the Punjab, and moderate rain had fallen during the previous 24 hours. The sky, however, rapidly cleared during the day, and was almost free of cloud by 4 Pp. Mm. Over the remainder of the Indian land area, excepting Burmah, the sky was clear and the weather fine. The following table gives the more important meteorolo- gical observations taken at the land stations :— (=) On no m » SO & = ae le & | Wind direction. |S 3 |S |7.5 we ro o . Lie} ee i836 Ree I8 lee 6B oem & = Stations, [S3G\2 > Age |g si é “| Weather. QHEIos PE. 18" eg A 2/0" -)loami| 4pm ead lo dey e Saal .a On PAlsolga a4 ala ~™ CRdol2"la 4a 3 Oo > Oo |fa Nancowry ...... |29°940] + ‘056 S.W. | S, W. 3 7 | 0°83 | Fine. Port Blair...... 29°896/ + ‘062;W.S. W.|W.S.W.}| 10 5 | 0°15 | Fine. Diamond Island] 29°826] + 167} 8. 8. 29 10 | 1:47 | Severe gale. PVA hives os 29°863|— °024| HE. N. E.| N,N. E. 5 10 | 0°59 | Showery. Chittagong ... |29°855|\~— 044) + N, Calm. 1 24 .../opmltry. Tounghoo ...... 29°881|— :004) N. W. | N. W. p 10 | 0°42 | Threatening weather. BRAGG 00) .ss05 29°830/ + 068) HE. S. H.| 8.8. E. 18 10 | .5°90 | Overcast. Rangoon wie. 29°887| + ‘017| EH. 8S. E.| 8.S. EH. 9 8 | 2°42 | Constant rain. Moulmein ,..... 29°902) + °033| S.S. H.| S.S. EH. 3 3 | 1:11 | Constant rain. Mergul ccjiess 29°943|+ °007| S. EH. | Calm. 2 5 | 0°30 1884.] of the Bay of Bengal in 1883. 161 The information extracted from the logs of vessels affectedt 1> cyclonic disturbance off the Burmese coast is given in the ensuing state- ment :— S o> : 4 3 z a 3 Winds. Vessel. Hour. 2 "Epa ~ 3 H REMARKS. 3 a onl. Sate Be ° os 2} Dir Force. 4 irs =| Shazada...... 8 a.M. |18° 14’/94° 00’ 29°836 | S. by E. Strong. Noon |18° 51'/93° 57’ Cloudy and overcast. 4P.M. “714 s. Mount Stuart 4 4.M. N. W. 5 |Sea heavy from N. E. by N. It was more 8 A. M. 29°870 ae 5 northerly towards. noon. 2P.M. Showery. Noon |14° 47’191° 20’ W.N. W. 5 4p.m. Heavy detached clouds. 5 P.M. Dull 4 P.M. C10) er 5 to 6 heavy sky, with bright pink colour 8 P.M. oe 5 at sunset. Midnt. ‘800 |vble.toW 5 PA secccv eee 4A.M. N. E. | Mode- | Cloudy, heavy easterly rate. swell, and squally. 8 A.M. N. Fresh. | Overcast and heavy N. E. swell. Noon /15° 54’ 90° 58’ ox .. |Squally, overcast, heavy N. E. swell. 4P.M. N. W. | Mode- | Overcast, N. E. swell rate. going down. 8 P.M. IDA W. a Moderate breeze and overcast. Swell gone down. Midnt. SW by W| Steady. | Moderate breeze and cloudy. _ Loanda ...... Noon |16° 16’,92° 54’|29°500| N. E. 10 | Gale increasing. Midnt. A hurricane. : Scottish Hill |8 a.m. 29°750 Noon. Heavy rain : ' squalls. Noon |15° 56/,92° 10’| *720|W. byS. 9 |6 Pp. Mm. Scud flying fast from N. W. 4P.M. ‘700 Severe squalls and | heavy sea. 10 P. M. } 6 P.M. ‘680 Weather clearer, sea lighter, squalls less ; 8 P.M. W. byS. 10 violent. Midnt. ‘790 162 Vessel. Byculla Satara see eee ee eee J. Khot—The South-West Monsoon Storms 3 ee Hour. E Z, 3 . H 3 g |S88| 7p; J S F: E - Dir. my NNW. to 4A.M. 29°610 |W. N. W. WNW. to} ° 8 A.M. *650|) S. W. Noon |16° 02/'93° 11’ °670|S.S. W. 4P.M *690/S. S. W. 8 P.M 790} 8.8. Midnt “770 |SE. by S. 2A.M 29°440|} W. 4 A.M 450) S. W. 6a. “460 8a.M °510|S. S. W. 10A.M 020 Noon |16° 10’198° 11’, *560 2P.M 580} 8. W. 4P.M “660 6 P.M “720 8 P.M “7BON) si0 10P.M B10} | ees Midnt "B30 ) wie 4A.M 29°520| S. EH. 8 A.M *630 Noon |16° 20’/93° 30, -680| S. E. 4P.M 670; S..E. ae a eee OO [No. 2, REMARKS. ‘Wind and sea going down. At short inter- vals, terrific squalls at- tended by heavy rain. Strong wind and heavy rain squalls. . Strong breeze and cloudy. Occasional heavy squalls. Strong increasing breeze, and cloudy weather. Heavy gale with dark overcast sky. Wind veered to S. W., in- creased and blew with great violence in terrific squalls with rain. High confused sea. 8 A. M. Heavy gale with terrific squalls from 8S. W. toS. 8. W. High confused sea. Shipping heavy water fore and aft. 11a. m. Weather moderating, but sea very confused.. Noon. Wind and sea moderating. Squalls less frequent and not so hard. 8 P.M. Strong breeze and overcast, with sharp squalls and heavy rain, high sea still running. Mid- night. Fresh breeze with passing squalls. Sea going down. 4. A.M. Fresh gale, vio- lent squalls of wind and rain, heavy head sea. 8 A. M. Strong gale, violent squalls, heavy rain. 10-45 A.M. Wind shifted to 8. by E. Noon. Strong gale Vessel. Hour. Remarks. Latitude N Longitude. E. Probable re- duced baro- meter. from S. E. Violent squalls of wind and rain. 4P.M. Fresh gale, violent squalls of wind and rain. Sea moderating. Wa- ter had a greenish tint. 6-30 P.M. Fresh gale, thick weather, with violent squalls. (Contd.) 6-15 a. M. Tremendous heavy sea from N. E. 10 a.m. Lulls andvery heavy squalls and 4a.M. a 7 Noon |16° 31/\91° 55’| °770 |W. N. W. 6 rain. 7 p. M. Clearing 7 4 3 Bancoora ... 8A.M. somewhat, wind and sea moderating, ves- sel at times rolling fearfully. 4P.M. 8 P.M. Midnt. 30°049 Mahratta ... | Noon |22° 00/|91° 44’ 29°910| S. E. 1 |4p.m. Slight swell from 8.E. To east- E. 2 wards, dense heavy . clouds ; to westwards, -780| N. E. 3 sky clear near the horizon; to north- H.N.E.to wards, light fleecy N. KH. 5 looking clouds, ap- parently motionless. Midnight. Sky com- pletely overcast, with occasional rain and heavy swell. The observations taken at the land stations show that the barome- ter had risen rapidly at Diamond Island, moderately at Bassein, Port Blair, and Nancowry, and very slightly at Mergui and Rangoon. It was falling slowly at Akyab and Chittagong, in front of the storm area. a eS eres 164 J. Eliot—The South-West Monsoon Storms [No. 2, Winds were much lighter at Nancowry and Port Blair, but were un- altered in direction, and continued to give moderate rain. They had veered to S. S. HE, in Burmah, except at Diamond Island, where they were from the south. A severe gale of wind had prevailed at that station during the previous 24 hours, but was beginning to moderate. Heavy rain had been brought up by the southerly winds into South Burmah. Bassein received 5°9 inches, Rangoon 2°4, and Diamond Island 1°47 during the previous 24 hours. The land observations are not sufficient to enable the position of the centre of the storm at this time to be inferred. The slight shift of wind at Diamond Island, the considerable rise of the barometer at that station, and the very small fall at Akyab, indicate that the storm was being largely influenced and retarded by the action of the Burmese and Arakan hills. The southerly winds in the easterly quadrant, instead of passing mainly over a water surface, were now blowing partly over South Burmah. The friction between the winds and the earth’s surface, and the action of the hills in breaking up and disintegrating the rotatory or vorticose motion of the air, evidently account for the change which was taking place, and which is more clearly shown by the ships’ observations. The Satara was in the north-east quadrant. Her position at noon was probably about Lat. 16° 20’ N. and Long. 94° E. She was between the storm centre and the Burmese coast, and received the full weight of the southerly winds during the day. She had strong gales with violent squalls and heavy rain during the whole day, and the weather only began to moderate about 8 Pp. m., after which she had a fresh gale with thick weather and heavy squalls. The position of the Loanda is slightly doubtful. She was almost in front of the cyclonic centre, probably a few miles only to the west. She had north-easterly winds of force 10 at midday. The storm increased, and at midnight was blowing a hurricane. Her barometer at midday (corrected) was 29°5. The Byculla was in the south-east quadrant. She had crossed the path of the centre on the previous evening at about 11 Pp. m., and steamed. away to the east during thé day. Larly in the morning, she was near the centre, and received the full weight of the south-westerly winds. The wind veered to south-west shortly after midnight, and blew with great violence ; terrific squalls of wind and rain passing over the ship at intervals. At 8 A. m., the wind blew a heavy gale with terrific squalls from S.S. W.and S. W., bringing up a high confused sea. Weather began to moderate after 11 A. M., and in the afternoon, when the vessel was pro- bably 200 miles away from the storm centre, she experienced fresh breezes with passing squalls. The barometer rose rapidly and continu- ously during the day from 29°44 at 2 a. mM. to 29°83 at midnight. of the Bay of Bengal in 1883. 165 , The Chanda and Bancoora were passing early in the morning through the south-west and south quadrants of the depression. The Chanda experienced terrific squalls with heavy rain. The winds com- menced at W. N. W., and hauled round to 8S. W. at 8 a. m. As she advanced south-eastwards during the afternoon, the weather improved, and wind shifted round to 8. E., when strong breezes with occasional squalls and cloudy weather prevailed. The Bancoora was further to the westward, and hence did not en- eounter such strong winds as the Chanda. During the day, the winds gradually shifted from north-west to west, and were of average strength _%. Very heavy squalls of wind and rain passed over the vessel, and a _ tremendous heavy sea came up from north-east early in the morning. As the storm centre passed to the northwards, and the vessel proceeded eastwards, the wind and sea moderated. The remaining vessels were at greater distances away. The Scottish Hill to the W. S. W. of the centre (in Lat. 15° 56’ N. and Long. 92° 10! i.) had very heavy rain squalls (force 9 to 10) during the day. The weather began to clear at about 10 P. m. The Asia, in Lat. 15° 54’ N. and Long. 90° 58’ E. at noon, was pro- ceeding south-eastward to Port Blair, and passed through the outer part of the south-westerly quadrant. She had squally overcast weather with a heavy N. EH. swell during the day. At midnight, she had steady, mo- derate S. W. breezes with cloudy weather. The Mount Stuart was in the west and south-west. quadrants, and experienced moderate winds of force 5, with occasional squalls. The Mahratta, between Chittagong and Akyab, had light variable winds, and fine weather, during the early part of the day. The sky clouded over and was overcast at night, when rain began to fall, and a heavy swell to come up. The Bhundara, off Gopaulpore, had light - airs or calms, and a clear sky. Assuming the position for the storm centre at noon to have been in Lat. 16° 10’ N. and Long. 93° EH., the following table gives its position with respect to the vessels near it :— Position. Direction of | Distance of Names of Vessels. Longitude.|Latitude.| storm centre | storm centre pia ‘ KE. from vessel. | from vessel. b-. NN dig. Sars coy G0 ob ulakst 16° 16’ | 92° 54/ N. N. W. 9 29°50 P RE OE oan acca ca viens, 16° 02’ O87 114 K. 15 29°69 P BOE N cu hs «od shies oor ges 16° 10’ 93° 11’ HK. 12 29°56 a ae eee 16° 20’ | 93° 30’ EK. N. E. 86 29°68 ge 0) 15° 56’ 92° 10’ W. 56 29°72 MMMMEDOOPS, Hive is scnccnisiss- 16 Oi" | G065" W. 74, 29°77 mount Stugrt. ©...... ive. 14° 47’ 91° 20’ S. 8. W. 140 29°85 ne ae 15° 54/ 90° 58’ W. 130 29°85 Tn 21° 59’ 91° 44/ N. N. W. 400 29°91 URES sos es ss cece Off Gopa ulpore. W. 29°89 ee — » 166 J. Hliot—The South-West Monsoon Storms [No. 2, 14¢h November.—The only feature of importance in the meteorology of India was the depression off the Arakan and Burmese coasts. Pres- sure was again giving way quickly over the Punjab, and to a less extent in all other parts of the country, except at a few stations in Bombay, South Madras, and in Arakan. The highest pressure (30°1) was over Sind, and the lowest (29°69) in Arakan at Akyab. Gradients were not steep, except in and near the cyclonic disturbance. The storm centre in the Bay was approaching Akyab at 10 4. m. The weather was overcast with heavy rain in Burmah and Arakan. A considerable in- crease of cloud had taken place in Lower Bengal. The sky had cleared in the Punjab and North-west Himalaya, and weather was fine over the whole of India, except in the immediate neighbourhood of the cyclonic disturbance. The winds were more northerly than usual in Northern India. In Bengal and on the Madras coast, winds were blowing chiefly from the north west. They were, however, as during the previous week, light in the neighbourhood. of the Madras coast. The following tables give the observations relating to the weather of the 14th taken at the land stations in the neighbourhood of the cyclo- nic disturbance, and the meteorological information extracted from the logs of vessels :— ots |O2 AO | |O a “3 ("6 | Wind direction. |S 2—& | |e S¥oe|oO i = ‘D> H q eS a for 5 a 4 - e Aa! ew ee a as} 4 = Stations. ate D ~ ae ab - S| & | Weather. g = 2 | G0 | 10 a.m. 4 P.M By sale igs R48 dd gaa olSala aa 3 Oo > Oo |m Nancowry ...... 29°921 : 019} 8. W. | S. W. 2 8 | 0°63 | Cloudy. Port Blair’...... 29°924 | + ‘028)W. N. W.| S. S. E. 6 6 | 0°61 | Cloudy. Diamond Island|29°898 + ‘072| 8. S. 17 7 | O64. TAD La siien oes 29°692|—" 171, N. W. 8 10 | 2°44 | Raining, Chittagong ... |29°772|— 083) N. W. W. 1 8 Gloomy. Toungoo ..... 29°866 |—" 015) N. W. | S. W. ? 10 | 0°15 | Showery. Bassein .......6 29°922|+°092)W.S. W.) SS. 14 10 | 1°42 | Overcast. Rangoon... 29°921;+°034, 8S. |8.S. W. 8 10 | 0°83 | Drizzling. Moulmein ...... 29'913/+°011| S. H. W. 4 1 | 0°33 | Fine. Mergui .......+ 29°948|+°005) N. HE. N. 1 8 | 1°55 | Cloudy. a a CE Ee 1884.) of the Bay of Bengal in 1883. 167 a |g (#3 Bie | fo. ja Vessel. |Hour.| 8&4 Ba lou x REMARKS, s | 8 (88s! pir sr H jg e Asia ........./4A.M. S WbyS. Moderate breeze and 8 A.M. S85. W. fine weather during Noon ;13° 26'/98° 27’ ze the day. 4P.M. 8. Light breeze. Shazada...... |8 A.M. 29°841 |W. N. W Noom. |14° 05’190° 50’ 4P.M. | °758|N.N.W Chanda ...... | 4.4. m. |15° 27/95° 15/|29°860 | S.S. W. Clear weather. 8 A.M. 860/58. 8. W. Bancoora ... | 44. M. 29°927 |W. S. W. 44.M. Heavy norther- 8 A.M. ed ey eA ly sea. Ship rolling Noon |15° 51’/93° 50’, 899] S. H. heavily. 6 a. mM. Mo- 4P.M. "812 8. derate breeze, heavy 8 P.M. °907 | EH. 8S. EH. confused sea, ship Midnt, 897| S. EH. rolling violently. Noon. Pleasant breeze and cloudy. Varies to Mount Stuart) 4. m. W. Heavy cross N. N. W. to Noon /15° 51’/91° 30’/29°890 4P.M. 8P.M. Midnt. Byculla...... | 2A.M. 4 A.M. 6A. M. 8 A.M. 10A.M. Noon |15° 58//93° 58’ 4P.M. 8 P.M. Midnt. N.N.E. sea which gra- dually abated. A flash of lightning ahead at 3 A. M. Passing clouds, weather gradu- ally getting finer look- ing. Passed through lots of bamboo roots to-day. Fine moon- light night. 29°780| S. W. 2 A. M. Fresh breeze “760 and cloudy. *820 4 A.M. Moderate breeze and cloudy, with pass- °860| S. ing squalls. 7 A. M. Water very much dis- 890 coloured, muddy ap- pearance, bottom 28 ‘890 fathoms. Moderate breeze and cloudy, °880; 8S. W. light passing squalls. 0-40 p. M. Sighted "920/)S.S. W. Alguada Light House toS. E. 1-30 p. m. ‘950| 8.8. HE. Light breeze and fine with smooth water. a 168 J. Eliot—The South-West Monsoon Storms [No. 2, Vessel. Hour. REMARKS. Latitude N Longitude. KE. duced baro- meter =) = 5] re) 3 oO ® oa {>} — ET oo oC ee je) mH a ee ee Satara ......;4A.M. 29°730| S. 8. E. 7 | Moderate gale accom- panied with heavy 6 squalls of wind and rain. 4A4.M. Strong 8 A.M. *850|S. 8. W. 6 breeze with heavy squalls. 5 A.M. Very Noon /16° 45/\94° 3’ 880 = 2 dirty weather, wind * moderating, very 2 heavy squalls, and sharp rain. 6-304.M. 4 Sighted land. 8 A.M. Strong breeze and 2 thick dirty weather. 10 a.m. Fresh breeze, weather clearing up generally, occasional heavy squalls. Noon. Light breeze and fine. Sea smooth. 4 P.M. Light breeze and fine, 8p. M. Sighted Al- quada Reef Light. Moderate breeze and fine. Sea smooth. Midnight. Light breeze and fine. 4P.M. 730 8 P.M. “900 Midnt. ‘900; S. W. Scottish Hill |4 a.m. 29°820| W. Sky clearing. Sea lighter, though much 8 A.M. PFO bs confused. Heavy sea from N. N. W. and Noon |17° 00’|92° 25’; -880 a N. Weather fine, but heavy bank of 8 P.M. W...N. W. clouds to N. N. W. and N. N. EH. Sea Midnt. °890; N. W. going down fast. Clouds clearing off. Loanda ...... |4A.M. Wind hauled round through N. Noon {17° 34//92° 46’ W. 7to8 | Weather overcast with light rain. Midnt. Weather improving. Mahratta ... |4A.M. 29°590|N.N.E. 9 Thick continual rain, 8 a.m.|Entere|d Aky-| °740|N.N.W. 8 with heavy sea ab. * A current set the ship from noon of 11th instant to noon of 14th instant N. 13° W. 171 miles. The barometer had risen at Diamond Island and all the stations to the south and east, except Nancowry, where a slight fall was observed. SS Pwr aaa = eT 1884. ] of the Bay of Bengal in 1883. 169 The rise was nowhere large, and was less than a tenth of an inch at all stations in that part of the Bay. A considerable (-17”) fall had occurred at Akyab, and smaller changes of the same character at Chittagong and Toungoo. Judging from the barometric movements, the centre at 10 a. M. was in the immediate neighbourhood of Akyab. The wind observations, however, are anomalous and almost unintelli- gible on the supposition of a well defined cyclonic circulation. The winds at Nancowry were steady from south-west, but were very feeble. At Port Blair, the wind was very unsteady, shifting from W. N. W. at 10 a.m.to 8.8. H.at4 p.m. Moderately strong S. W. winds continued at Diamond Island. The winds at 10 a. mM. at Akyab were from N. and at Chittagong and Toungoo from N. W. They shifted at 4 Pp. mu. to west at Akyab and Chittagong, and to 8S. W. at Toungoo. They were, however, very feeble at all these stations. The wind velocity averaged 8 miles per hour at Akyab, and only 1 mile per hour at Chittagong, where the air motion was actually less than the average in November, which is 2 miles per hour. The only inference from these observations is, that the cyclonic or vorticose motion had been broken up to a large extent by the action of the hills and the friction of the land, and that it was no longer a well-defined cyclonic circulation. This is also indicated by the character of the rainfall at the land stations. It was more widely distributed than before, and was smaller in amount, the largest quantity registered being 2°44 inches at Akyab. The vessels which have contributed logs were all on the southern and western quadrants at some distance from the centre. They give in- formation which is less valuable and conclusive than that of the preced- ing days. The whole of the meteorological observations, when charted, indicate that the centre of the barometric depression at 10 A. M. was to the east of Akyab in Lat. 20° N. and Long. 933° E., and that the cyclonic circulation was very irregular and fast breaking up. The Mahratta, from Chittagong, entered Akyab harbour at 8 A. mM. She had thick continued rain during the night with northerly winds of force 9. The Scottish Hill, in Lat. 17° N. Long. 92° 25’ E., was to the south of the centre at noon. She had winds from west to north-west. During the day, the sky cleared, and the sea went down. At noon, weather was fine, although a heavy bank of clouds was still to be seen to the N. N. W. and N. N. H., but it cleared off during the night. The Loanda, in Lat. 17° 34’ N. and Long. 92° 46’ K. by account, had westerly winds, and overcast.skies with slight rain. The Satara found herself at noon in Lat. 16° 45’ N. and Long. 94° 3’ EH. She experienced moderate winds of force 7 from 8. 8. EH. early in the morning, and continued to have sharp squalls and heavy rain until 170 J. Eliot—The South-West Monsoon Storms [ No. 2, 6 A. M., after which the weather rapidly improved. A fresh breeze was blowing at 10 a. M. with occasional heavy squalls. At noon, the storm was completely over, and she had light breezes of force 2 from the 8.8. W., fine weather, and a smooth sea. The Mount Stuart, in Lat. 15° 51’ N. Long. 91° 30’ EK. at noon, had westerly winds of force 5 early in the morning, with a heavy cross sea. The weather improved rapidly, and was quite settled in appearance at night, with fine clear skies and light winds of force 1 to 2. The Byculla, Bancoora, and Chanda were steaming along the south coast of Burmah towards Rangoon. They had fine weather with south-westerly winds of average force 3. It thus appears that the first action of the Burmese hills, which are comparatively low, had been to retard the advance of the centre very con- siderably between noon of the 12th and of the 13th. During the next 24 hours, it advanced rapidly almost due northwards with a very slight easterly tendency. It then approached the coast to the east of Akyab on the morning of the 14th. The depression was, however, very much smaller than hitherto, and the cyclonic motion very considerably broken ‘up. The winds were irregular in direction near the centre. The rainfall was evidently much less in amount, and more widely distributed. The observations taken at Akyab and Chittagong at 4 p.m. shew that the disturbance was then almost completely disintegrated. There was at that hour an irregular, but very feeble, cyclonic circulation, which passed away before the following morning. 15th November.—The meteorology of the 15th is given to show how completely the cyclonic disturbance had broken up. The barometric changes of the previous 24 hours were exceedingly irregular. The only important change was in Arakan, where the baro- meter had risen very rapidly with the disappearance of the cyclonic disturbance. The winds show very little alteration generally. In the North-West Provinces and Punjab, they were very variable. In Bengal and Orissa, they had a much stronger northerly component than is usual in November. The weather was fine, and skies were clear over nearly the whole country, except Burmah and Arakan, where they were still more or less clouded, and moderate rain was falling. In the Punjab, though the sky was generally clear and humidity decreasing, the weather still appeared unsettled. The exceptional character of the weather in the Punjab during the previous week, is illustrated by the fact that the average rainfall of the hill stations at Simla and Chakrata for the month of November is nil, whilst, during the previous fifteen days, four inches had fallen at the former station, and 33 inches at the latter. of the Bay of Bengal in 1883. 171 The following tables give the observations of the same stations as hitherto, and the meteorological information from the logs of several vessels in the Bay for the 15th November :— og |o2 mo. [2 lo se Shee He Be tigen pas S93 9/85 EAE 5 x a) *| Oo Stations. 8 fea ra ee a & = 3/8 5 | Weather. os : ' - (ea BH | 5) 10 aa. 4pm. |B, 4 mle 41a 8 8 R Oo |m Nancowry ...... 032} BL 2 8 | 1°47 | Cloudy. Port Blair...... 29°932|+ 008) N.N.E.| EH. S. E. 5 3 | 0°13 | Fine. Diamond Island |29°937 |+ °039) E. S. EH. | H. 8. E. 7 6 | 016 | Fine. Bead. ...:...... 29°937|+ °245) 4H. S.S. EH. 5 9 | 0°33 | Gloomy. Chittagong .., |29°925|+ °153| 8.8. H.|S. 8. W. 2 6 Gloomy. Tounghoo ...... |29°913 |+ ‘047; N. W. | N. W. p 6 | 0°04 | Drizzling. Bassein ......... 29°952 |+ °030; 8.8. E.| W. 3 10 | 0°04 | Cloudy. Rangoon ...... 29:952|+ -031| §.E. |S.S8.E.| 5 | 9] 0-74 | Cloudy. Moulmein ...... 29°899 |— 014; N. W.H. 2 0 Fine. Mergui ......... 29°920 |— °028) Calm. aN; 1 10 | 1°50 | Overcast. g§ |g [FE Winds. © 2 Vessel. Hour. 27 ‘ee = 3 H | REMARKS. 4 S S 3 3 Dir. | Force. = Shazada...... 4.A.M. 29'911|N.N.E.| Light. | Weather fine with light 8 A.M. winds. Noon |12° 47’87° 14’ 4p. M. ‘781|N.N.E.| Light. 8P.M Satara ...... 4A.M. 29°870| S.E. 2 | Light breeze and fine clear weather. 8 A.M. "940 ee 4 | Moderate breeze and fine weather, Noon |15° 50/\95° 50’) *980|_ ... 4 |Current during the previous 24 hours, W. 65 miles. 4P.M. *810! N. E. 2 | Light breeze and fine weather. 172 J. Eliot—The South-West Monsoon Storms [ No. 2, Vessel. Hour. REMARKS, duced baro- ere ae) B 5 Re] a4] ap - a 3 ° 4 —— | OOOO - | | | | Probable re- ASG TT ranae 4A.M. Variable| Light | Light and variable airs, fine weather. Noon | Port /Blair. 5 Ste 4 P.M. E.N.E.| Light | Light breeze and fine clear weather. 8 P.M. PAs Fresh. Mount Stuart) 4. M. N.N. W. 1 /1 Pe. mM. Smooth with light N. swell. 4P.M. 8 A.M. N. by E.| 1 to 2 Heavy clouds all round the _ horizon. Noon |16° 24’ 92° 00/|29°890|N. N. BE.) ... 5 p.M. Weather set- 4P.M. NE by N 2 tled looking. NNE to Midnt. NE by N 2 | Midnight. Clear fine weather. Scottish Hill |8 a.m. N. W. Light winds and swell from N. N. W. Noon |18° 03//92° 48’/29°900 ; 8 P.M. NNW to Light winds and clear sky. Loanda ...... Noon /18° 38//92° 30’|29°800 | W by N. 5 The observations call for little remark. The rapid recovery of pressure at Akyab, and the lightness and irregularity of the winds in Arakan and Burmah, indicate the complete disappearance of the cyclonic vortex. The land observations show that the winds were very unsteady during the day. For instance, at Nancowry, they were from east at 10 a. mM. and south at 4p. mu. Similarly, at Port Blair, they shifted from N. N. H. at 10 a. wm. to S. S. H. at 4 p.m. It is probable that these were light local winds, for the logs of the vessels prove that, over the greater part of the Bay, north-easterly winds were again established. The Clan Macpherson, at the entrance to the Bay, in Lat. 6° N., had moderate north-easterly winds. Hence the cyclonic circulation had not only broken up, but the south- westerly winds which had, as shown by the Nancowry registers, prevailed steadily up to the afternoon of the 14th, although they had decreased in strength considerably during the 12th, 13th, and 14th, had given way so : ; 7 { —— 1884.) of the Bay of Bengal in 1883. 173 rapidly and entirely on the afternoon of the 14th, that light north-easterly winds were again established over nearly the whole of the Bay on the morning of the 15th. This speedy restoration of the normal circulation of the air after. the disappearance of the disturbance, is perhaps less remarkable than it might seem to be, but is nevertheless noteworthy. CHAPTER IV. DiIscussioN OF THE CHIEF FEATURES OF THE StoRM OF NovemsBer lOru tro 1ld5ruH. The following gives a brief connected narrative of the more im- portant features of the storm. After the termination of the south-west monsoon in Bengal in the last week of September 1883, the winds shifted round to north over the Head of the Bay, and the lower air current of the south-west monsoon recurved over the middle of the Bay. The north-east monsoon hence commenced on the Madras coast during the first week of October. Un- usually heavy rain fell over Southern India, more especially over the eastern districts of the Madras Presidency, during the month of October and the first week of November. During the whole of this interval, the period of the year when the most severe and extensive cyclones are known to occur, the Bay was entirely free from storms. In the beginning of the second week of November, the rainfall rapidly decreased in amount in Madras, and ceased entirely on the 9th and 10th. The logs of vessels shew that winds were, at that time, as they had been for some days previously, very light and variable in the neighbourhood of the Anda- mans and Nicobars. South-westerly winds were re-established at Nan- cowry on the 4th, and south-easterly winds at Port Blair on the 7th, but they were at first very weak. The wind observations taken on board the ships Mount Stuart and Scottish Hill prove that, at the same time, winds were unusually light over the centre of the Bay, in the neighbourhood and to the west of the Nicobars and the Andamans. This condition of excessively feeble air motion was very marked on the 7th and 8th. On the 9th, there were indications for the first time of the occurrence of moderately heavy and localized rainfall to the north-east of the Nicobars, and to the east of Port Blair, and also of a shift of wind, significant of the commencement and establishment of cyclonic circulation. On the morning of the 10th, there was a well-defined atmospheric whirl to the east of Port Blair. Weather was at that time cloudy, with very light breezes, and occasional passing showers ; and the sea was smooth, and free from any considerable current over the greater part of the Martaban Gulf, and the north and centre of the Bay. 23 174 J. Eliot—The South-West Monsoon Storms [No. 2, The ship Kwang Tung, it may be remarked, passed, on the 7th and 8th, over the area in which the disturbance was generated ; and there is not the slightest indication in her log, or in the observations of the neighbouring land stations, of the existence of any atmospheric whirl, large or small, at that time, or previous to the 10th. The central depression at noon on the 10th was very small, probably less than a tenth of an inch, and the atmospheric whirl, although clearly established, was as yet in an initial state. It, however, rapidly acquired increased energy during the afternoon of the 10th, and the morning of the llth. At noon of the 11th, there was a well-defined cyclonic disturbance with its centre in Lat. 134° N. and Long. 942° E., the barometric depression at which certainly exceeded 3". Strong winds were now blowing into it from the south, and bringing up much vapour. During the succeeding 24 hours, the centre moved to the north-westward through the channel separating Diamond Island and Cape Negrais from the Andaman Islands, and probably over the Coco Islands. Its centre, at noon on the 12th, was in Lat. 152°. N. Long. 93° E. The disturbance was of small extent, as vessels at distances of only 150 miles had light to moderate winds of force 3 to 5. The Satara, Byculla, and Loanda, all of which were near the centre, on the other hand, experienced squalls of terrific and hurricane force. Henee it was at that time a small but well-defined atmospheric whirl or eyclonie disturbance. The winds and squalls near the centre were of the most violent character, the sea excessively high and dangerous, and the currents in the eastern quadrant considerable. During the next 24 hours, it retained the same characteristics, but moved very slowly to the north, so that, at noon, its centre was in Lat. 16° 10' N. and Long. 93° E. The retardation of its motion was evidently due to the resistance of the land and hills in the eastern quadrant. The centre passed a few miles to the east of the Loanda and the Byculla on the evening of the 12th and morning of the 13th. The decrease in the indraught from the eastern quadrant due to the action of the Burmese and Arakan coasts continued. The whirl began to diminish in intensity, and also recurved slightly after noon of the 13th, and passed to the north-north-eastward, thus approaching the Burmese and Arakan coasts. On the morning of the 14th, it was much enfeebled. The barometric depression was smaller in amount, the winds weaker, the rainfall more diffuse and less localised, and the sea less violent. Moreover, the directions of the winds were so irregular over the area of barometric depression as to suggest the existence of several imperfect and feeble vortices, rather than of’ one large and well-defined whirl. The centre of the depression was in the neighbourhood of Akyab on the morning of the 14th. The land observations at 4 Pp. mM. of that day i 1884.) of the Bay of Bengal in 1883. 175 indicate that the cyclonic circulation was completely broken up, and that fine weather, with moderate winds, and aslight sea, obtained at that hour in the north-east of the Bay, over which the cyclone had previously advanced. The disturbance passed so completely away on the 14th that normal north-easterly winds were re-established over the greater part, if not the whole, of the Bay, on the morning of the 15th. The storm hence was generated and dispersed between the morning of the 10th and the evening of the 14th. The following are a few of the more important points in connection with this cyclone, One of the more remarkable features, which has already been dis- cussed, but which deserves special mention, was the change which occurred when the cyclone approached the Burmese coast. Whatever the explanation may be, there can be no doubt of the facts. The following table gives approximately the position of the centre at noon on the various days, and the distance passed over by it in the preceding 24 hours :— Position of Centre. | Distance passed over in pre- ceding 24 Latitude. | Longitude.| hours. nn ee en? eS 1 1s? By eae EB ly Hae. elscemieed.... 115° 801 98° 0% | 160 miles, ecg ie ae | lee Lit 98" 0) AG Seen Benoit hy dla De aha) ogge yy Wmgge sor oT Saye» It will thus be seen that, between noon of the 12th and 13th, the storm centre began to recurve, and only advanced a distance of about 50 miles, as compared with 160 miles during the previous 24 hours, and 275 during the succeeding 24 hours. The only apparent explanation depends on what I have already suggested as probable, namely, that the cyclonic action extends through very different heights in different storms. In the storms of the rains proper, it is almost certain that the condensation, and therefore the seat of the disturbance, is at a much greater elevation than it is in storms formed during the October Tran- sition period. In the latter case, the storms appear to be generated 176 J. Eliot—The South-West Monsoon Storms [No. 2, near the northern limit of the retreating south-west monsoon current, which is at that period diminishing in strength. It is probably much shallower at its northern limits than elsewhere. Many of the pheno- mena of the cyclones of the Bay appear to be intelligible and explicable only on this supposition. If it be granted that the October and November storms of the Bay of Bengal are formed near the northern edge of a diminishing and retreating current, it is hence almost certain that the vapour condensa- tion, in the case of the November cyclone under discussion, occurred at a comparatively small height in the atmosphere, and that the resulting motion was mainly confined to the lower strata. Hence the effects due to friction with land, and to the destructive or disintegrating action of the hill barriers of Burmah and Arakan cutting almost radially across the cyclonic area, would be large and marked. This was undoubtedly the case. So long as the cyclone was to the south of the Burmah coast, the cyclone increased in intensity. When the centre was in a line with the coast, and at a short distance from it, retardation was at once shown, and the cyclonic or vorticose motion began to diminish. And as the centre advanced northwards, so that the Arakan hills (of greater height than the west Burmese hills) were included within the area of disturbance, the disintegrating action became rapidly more marked, and caused a speedy disruption of the vortex. A feature which deserves special notice in the smaller cyclonic storms of the Bay is the behaviour of the barometer. The barometer affords practically no indication of the approach of a small cyclonic storm in the Bay, and should not be trusted by the mariner to give due warning. The reason of this is simple. A favourable condition ante- cedent to the formation of a storm is approximate uniformity of pressure over the whole or a large portion of the Bay. If a small atmospheric whirl be set up in an almost, quiescent mass of air, which is therefore under nearly identical and uniform conditions, it produces a small de- pression at and near the centre, which extends slowly outwards. The fall of the barometer at distances of 80 or 100 miles from the centre is generally small in amount, and is frequently less than the changes due to general actions common to the whole of India. The depression at the centre rarely exceeds half an inch, and steep baric gradients are confined to its immediate neighbourhood. Over the rest of the Bay, the pressure is slightly affected by the indranght, but frequently not to such an extent as to obscure the changes going on over the whole of India. In other words, during the formation and existence of a small storm, the barometer immediately outside of the storm area pro- per oscillates in obedience to the larger atmospheric movements com- 1884.) of the Bay of Bengal in 1883. 177 mon to the whole of India, as well as to the distant storm, and hence, if used as a guide to the weather, it should be remembered that its indica- tion may refer mainly to these general movements, and not to the whirl in the neighbourhood. Hence it cannot be used as a reliable guide to the existence of small storms in the Bay of Bengal. A few examples from the present cyclone will not only indicate that the barometer gives no certain and marked warning of the approach of a smaller cyclone in the Bay, but suggest that the mariner in the Bay of Bengal should rely mainly on the appearance of the sky, the strength and changes of the wind, the amount of the swell, and the direction from which it travels, as indications of an approaching storm. The Mount Stuart passed through the western quadrant. The fol- lowing table gives her barometric readings, her position with respect to the storm centre, strength of wind, and amount of swell :— Distance Barometer.|} Wind. Swell. [of storm Weather. centre. PER oie .ce 29°90 2to3 | None sles Unsettled. tht uc... 92 lto4! None tae Unsettled. 1 ere 87 0to3 | None — Unsettiled. 20th: . 86 0 to 4 None a Unsettled. ae 82 2 to 5 None 250 | Weather looking very bad. 12th . 75 5 to 6 4 100 =| Squally. 13th . 87 5 to 6 | Heavy sea.} 125 | Squally. 14th . 89 5 tol | Heavy. 280 | Fine. The preceding table shows that, although she was within 100 miles of the centre of a storm between the 10th and 14th, the range of the barometer at noon during the whole interval was only ‘14”, or very little more than the diurnal range of the barometer in the Bay. The Bancoora may be taken for another example :— Barometer.| Dist- | Wind. Swell. Weather. ance. llth ...| 29°887 | 550 2 to 4 None. Fine. 12th ... 805 | 250 4to5 | Heavy N. E. sea. | Squally. 13th ... ‘770 70 3 to 7 | Tremendous sea in| Very squally the morning. Heavy sea during the after- noon. 14th ... 839 | 280 2 to 3 Heavy sea. Improving. 178 J. Eliot—The South-West Monsoon Storms ‘[No. 2, The above shows that the Bancoora, which left the River Hooghly on the llth, approached within 70 miles of the centre of the cyclone at noon of the 13th. She had heavy squalls and a tremendous sea, and yet the total range of her barometer, as determined by the noon observa- tions, was only ‘117’, or actually less than the diurnal range of the barometer in the Bay. The Satara furnishes equally strong evidence. She was for a con- siderable time in the eastern quadrant of the cyclone at no great distance from the centre, and hence felt the full foree of the storm. Barometer. | Dist- | Wind. Swell. Weather. ance. 10th ... 29°89 2to5 | None. | Fine. llth ss. *80 | 250 4 to 6 | Heavy és. Gale. Heavy squalls. ach... ‘61 90 9 | Heavy sea.) Hard gale. 13th ... 68 39 8 to 9 | Heavy sea.| Strong gale. The preceding observations show that on the 11th, when the state of the sea and the strength of the wind indicated the existence of a cyclonic storm, her barometer had not fallen a tenth of an inch. It was only on the 12th, when she was ‘in the midst of the storm, and the wind had increased to force 9, and was blowing a hard gale, that the barometer began to fall to any considerable extent. | These examples appear to establish that the barometric movements are very small in the outer portion of the smaller cyclonic disturbances of the Bay, and are generally smaller than those due to the regular changes common to the whole of India. Hence the barometer gives little or no practical warning of the approach of a small cyclone in the Bay, and mariners should therefore rely mainly on other indications. The path of the cyclone was contrary to all recorded experience of storms in the Martaban Gulf. The following is the list of storms that have been known to occur in that portion of the Bay, taken from Mr. Blanford’s Catalogue of the recorded Cyclones in the Bay of Bengal, up to the end of 1876, in Journ. As. Soc., Bengal, 1876, Vol. XDVI, Pt. If :— al 1840—November 21st. To the N. E. of the Andamans. 1844—November 9th—14th. Hast of the Andamans. Encountered by 1884. ] of the Bay of Bengal in 1883. 179 the Briton and Runnymede troop ships. Both vessels were dismasted and thrown on the Andamans. 1850—November 17th—19th. In the Andaman Sea. Passed east of Port Blair and travelled N. N. W. 1854—A pril 21st—23rd. A violent hurricane in the Gulf of Martaban ~ and Rangoon. 1858—April 9th—10th. A storm from the Andamans to Cape Negrais. Much destruction of property occurred at Henzada and Rangoon, between which the centre passed. There is no direct evidence in this list that any of these storms passed from the Martaban Gulf into the Bay of Bengal. It is, however, probable that the third storm in the list did so. It appears to be parallel in time of occurrence, and line of advance, with the storm under discussion. There is no apparent theoretical reason in support of the opinion that a storm generated in the Gulf of Martaban should not pass into the Bay. Experience certainly appears to indicate that such a line of motion is very rare. The great majority of the cyclonic storms in the Gulf of Martaban are generated to the east of the Andamans and north-east of the Nicobars, and advance in a general northerly direction across the south coast of Burmah, when they rapidly break up. Hence, although experience is doubtless valuable in indicating the probabilities of the occurrence of cyclones, and their line of motion, it should be most carefully borne in mind, that they are mere probabilities based, at the present time, on very limited experience, and that it would almost certainly be misleading and dangerous to dogmatize our limited experience into rules or laws, which might fail on their first application. Another feature deserving notice was the short period of its exist- ence. Favourable conditions, according to the condensation theory, were present for some days previous to the 10th. The log of the Kwang Tung for the 7th proves that there was no cyclonic vortex in existence in the Andaman Sea on that day. The various observations of the 8th and 9th indicate that cyclonic motion on a considerable scale had not commenced on either of these days. The observations of the 10th, on the other hand, establish the existence of a small depression on that day which rapidly developed into a large atmospheric whirl. Hence the existence of the cyclonic vortex dates from the evening of the 9th, or morning of the 10th. The circulation intensified and developed rapidly on the evening of the 10th and morning of the 11th, so that there was a large barometric depression and cyclonic circulation on that day, to the north- east of the Andamans. The cyclone was then moving north-westwards. 180 J. Eliot—The South-West Monsoon Storms [No. 2, It continued to accumulate energy until the morning of the 12th, when the action of the land on the atmospheric motion in the eastern and north-eastern portions of the cyclone retarded the advance of the vortex, and began to influence the cyclonic motion considerably. This proceeded at first slowly, but, as the storm moved northwards, the destructive effect of the Burmese and Arakan hills increased, so that the rotatory motion was gradually and completely broken up and disintegrated before the afternoon of the 14th, in the neighbourhood of Akyab. There was thus a period of about 48 hours, from the morning of the 10th to that of the 12th, during which the storm accumulated energy. During the next 24 hours, the rotatory motion continued almost undiminished, whilst the motion of translation was largely decreased. During the remaining 36 hours of its existence, the vorticose or rotatory motion was gradually diminished. The force of the winds at and near the centre (which might perhaps be used to measure the intensity of the storm) depends mainly upon the strength of the atmospheric disturbance producing the cyclonic motion, that is, upon the rate at which aqueous vapour is condensed into rain and upon the character and distribution of the rainfall (7. e., whether it is localized and concentrated over a comparatively small area or diffused). On the other hand, the extent of area over which the cyclonic dis- turbance extends appears to depend mainly, if not entirely, upon the length of time that has elapsed from its formation, and during which it has advanced over the sea area uninfluenced by the land. Hence it is that the most extensive cyclones have been generated in the centre of the Bay, near the Andamans, and have advanced northwards to the Bengal coast. This is not due to any meteorological peculiarity of the Bay in the neighbourhood of the Andamans, but to the fact that a cyclone generated there, and advancing northwards, takes a longer time to reach the land than if it were formed in any other part of the Bay, and has therefore a longer period during which its energy can increase. CHAPTER V. ConcLupING REMARKS ON THE CONDENSATION THEORY. In the preceding pages, all the observations throwing light on the two largest and most severe storms in the Bay of Bengal during the year 1883 have been given, together with a discussion of their more im- portant features. It remains to explain the chief features of the two storms as physical phenomena, and hence also to suggest the theory of cyclonic generation and motion which appears to be applicable to them, and is consistent with our knowledge of the physics of the atmosphere. —_ i i Be 1884.] of the Bay of Bengal in 1883. 181 In both examples, the greater portion of the mass of air that was thrown into a state of violent motion during the storm was for some days ante- cedent to the disturbances almost at rest, and in a state of approximate equilibrium. There was a break in the rains immediately preceding the formation of the first storm, which is well-known to be a period of light and unsteady winds in Bengal, and over the Head of the Bay. The second storm occurred very shortly after the first break in the north-east mon- soon rains on the Coromandel coast, and when, as the various observations prove, winds were very light and variable over the greater portion of the Bay. Hence the first and most striking feature of these cyclones was, that a vast amount of kinetic energy, or motion, was rapidly given to a large mass of air which, previously to that action, was in an almost quies- cent state. The gradual increase of the motion was in those two examples proved from observations taken by vessels passing through the areas of disturbance. The transformation from the state of approximate quiescence to that of violent cyclonic motion in the Bay is consequently a continu- ous process, the successive stages of which can be fully traced. And the entire development of these, and of all storms in the Bay of Bengal, appears to be due to actions occurring over the Bay itself, and not to atmospheric conditions at a considerable distance from the area of cyclonic disturbance. The question of cyclone generation is therefore essentially one of transfer of energy. Viewed in this light there are two subjects for enquiry :— lst. The source and character of the energy which is transferred to the atmosphere, and transformed into the kinetic energy of a mass of alr. 2nd. The conditions necessary for the transfer of energy under consideration. If these two questions are fully answered, a satisfactory explanation will be given of cyclonic generation as a meteorological problem. The complete mathematical treatment of this subject as a dynamical question is beyond the scope of the present article. The energy which is transformed during the generation and exis- tence of a cyclone, and which maintains the cyclonic circulation against the various resistances opposing it, and therefore tending to disinte- grate it, is undoubtedly the latent heat energy given out during the condensation of aqueous vapour contained in the atmosphere. In all cyclones of the Bay of Bengal that have hitherto been investigated, heavy and, in the majority of cases, torrential rain is the most pro- minent feature. It increases in amount during the generation of the cyclone, is excessive during the existence of the cyclone in its complete 24 182 J. Eliot—The South- West Monsoon Storms [No. 2, form, and rapidly decreases during the disintegration of the cyclone, ceasing with the disappearance of the cyclonic vortex. It is thus a phenomenon parallel in character and duration with the cyclonic motion or disturbance. It is also equally certain that when aqueous vapour is condensed into rain, practically the whole of the solar thermal energy utilized to perform the work of evaporation is given out by the mass of vapour during condensation, and is transferred to the adjacent mass of air. Major Cunningham’s Hydraulic Experiments at Roorkee appear to establish that the sun’s heat under the most favourable conditions, that is, dry weather and high air temperature, does not evaporate more than one-tenth of an inch per diem from the surface of slowly moving water. The inverse process of condensation, in consequence of certain features of air motion dependent on rainfall, usually proceeds much more rapidly, and frequently restores the aqueous vapour in the form of rain to the earth’s surface at the rate of one to two inches per hour. Prolonged rainfall at the rate of 10 to 30 inches per diem for periods varying from 24 to 72 hours are by no means uncommon during the passage of the larger cyclones of the Bay of Bengal across the Bengal or Madras coasts. It is probable, judging from the expressions used by © sailors to describe the rainfall during cyclones in the Bay, that it is more intense and prolonged than on land. If we therefore compare the rates at which evaporation and condensa- tion can occur, it is certain that the energy released during the act of con- densation is transferred to the atmosphere with very great rapidity during heavy rainfall and probably at a rate occasionally amounting to 100, 200, or even 400 times that at which it was absorbed during the process of evaporation. The effect of a continuous fall of 20 or 30 inches of rain over any portion of the earth’s surface would, on the assumption of Major Cunningham’s results, be equivalent to that of a sun 250 times as powerful as our present luminary acting directly on the mass of the atmosphere above the area of rainfall, instead of indirectly by means of convection currents due to the heating of the earth’s land surface. The action is also usually continuous, and is not interrupted, as in the case of the direct solar action, by the succession of night and day. There is therefore the strongest probability that so powerful a disturbing action can produce very large and rapidly accumulating effects on the mass of the earth’s atmosphere affected and influenced by it im a com- paratively short space of time. There hence appears to be no doubt that the energy transferred to the atmosphere during heavy rainfall is very large, and that the source of the energy thus indicated is adequate from every point of view to account for the production of the largest and most intense cyclonic cir- 1884. ] of the Bay of Bengal in 1883. 183 culations. Other causes of the origin of cyclones have been assigned, as, for instance, differences of pressure, friction between parallel winds blowing from opposite directions, &c., but the slightest consideration seems to show that none of these is sufficient to account for the enormous and continuous transfer of energy that occurs during the prolonged existence of a large cyclone. The strongest argument against these theories, in the case of cyclones of the Bay of Bengal, is, that experience has established that the larger the cyclone, the smaller are the antecedent differences of pressure, and the feebler are the winds blowing from opposite directions, immediately before the formation of the cyclonic vortex. The following statements based on the preceding remarks hence give the answer to the first part of the required explanation. When water is converted into aqueous vapour on the large scale at the earth’s surface, thermal energy, derived from the sun, performs the work of evaporation, and is hence transformed. The aqueous vapour thus produced possesses an equivalent amount of energy, the greater part, if not the whole, of which it retains, so long as it continues in the vaporous condition. When it is reconverted into water, or condensed as rain, this portion of its total energy is given out, and transferred to the air. The modus operands of this transfer is a matter of no importance in the present enquiry. Also, in all cases when the rainfall is heavy, and prolonged for a con- siderable time, the energy is given out at a much more rapid rate than that at which it was absorbed during the process of evaporation. Hence heavy and prolonged rainfall may give rise to a powerful, persis- tent, and continuously accumulating disturbance on the adjacent atmos- phere, and, therefore, produce violent and extensive air motion. In virtue of the constitution of the atmosphere, the motion will be rotatory. Pro- longed heavy local rainfall is hence an adequate and sufficient cause. It is, moreover, the only known cause which is equal or similar in amount to the effect, and hence there are strong reasons for assuming that it is the motive power which produces the peculiar motion of the atmosphere called cyclonic circulation on the large scale. It is, in fact, the most powerful disturbing action to which the air is subject, and the consequent motion of the air is, when the rainfall and consequent disturbance are excessive, the most violent in its character with which we are acquainted. The history of the two cyclones has shewn most fully that heavy rainfall over the area of cyclonic motion or disturbance was a charac- teristic feature, and that in this respect they confirm previous experience. Hence the source of the energy of these two cyclones was almost cer- tainly that which we have indicated in the previous statement, that is, the latent heat energy of the aqueous vapour derived previously from the sun, and transferred to the atmosphere during the process of con- densation. 184 J. Eliot—The South-West Monsoon Storms [ No. 2, As rainfall does not always appear to produce cyclonic motion, it is clear that, although rainfall may be the source of energy, it is only when. the rainfall occurs under special conditions that the accompanying air motion increases and accumulates in the peculiar manner necessary to give rise to a large and intense cyclonic circulation. Experience has shown that the following conditions, which can be proved to have a direct bearing on the formation of cyclones, are always present before and during the generation of cyclones in the Bay of Bengal :— 1st. The establishment and prevalence of a humid current over the extreme south of the Bay, which brings up large quantities of aqueous vapour into the centre or north of the Bay. 2nd. The occurrence of approximate uniformity of meteorological conditions, more especially of pressure, over the coasts of the Bay, and frequently over a considerable portion of the Bay. 3rd. The prevalence of light and variable winds over Bengal and the coasts of the Bay, and over a considerable portion of the Bay extend- ing from the Bengal coast southwards. This condition is practically identical with the previous, as both are due to, and accompany, the same general atmospheric conditions. 4th. The absence of rainfall, and the prevalence of clear skies with fine weather, over the north and centre of the Bay, and in Bengal. The relative importance of these conditions will be evident on very brief consideration. The first is evidently necessary to supply the aque- ous vapour in sufficiently large amounts to give rise to continuous heavy rainfall over such a large area as is covered by a considerable cyclonic disturbance. The Bay of Bengal is not a large enough evaporating area to afford such a supply. Hence cyclonic storms are only formed in the Bay of Bengal when there is a humid current blowing into it from the Indian Ocean. This occurs only during the south-west mon- soon period, when the south-west winds blowing at the entrance of the Bay are the northward continuation beyond the Equator of the south- east Trade Winds of the Southern Tropics. That such is the case is sufficiently proved by the fact that cyclonic storms on the large scale are entirely restricted to that portion of the year when south-west mon- soon winds are blowing over a part or the whole of the Bay, that is, from the beginning of May to the end of December. It is also shown by the fact that, at the commencement and termination of the south-west mon- soon period, any cyclones that are generated, form in the south of the Bay, whilst in the months of July and August, or during the height of the south-west monsoon, they form near the Head of the Bay. In short, the area of cyclonic generation in the Bay of Bengal depends mainly upon the season, and travels northwards or southwards, according as the south-west monsoon is advancing or retreating over the Bay. 1884. ] of the Bay of Bengal in 1883. 185 The remaining conditions appear to be necessary in order that the rainfall may occur in such a manner as to give rise to and produce an atmospheric whirl. It is evident that if rainfall tends to set up rotatory motion in the air, it is absolutely necessary for rotatory motion on the large scale that there should not be several separate centres of rainfall and disturbance, each producing its own rotatory or cyclonic action, and _ therefore interfering with the others. It is essential that the rainfall — be localized and concentrated, that it should continue for some _ time over a comparatively small area, and be confined to that area. The - more perfectly this is realized, and the longer this continues, the greater _ will be the accumulated disturbance. In order that the rainfall may occur over the same area for such a considerable period as to permit of _ the continuous accumulation of action, it is evident that ascensional _ motion should mainly occur there, and hence that, previously, there should be little horizontal motion of the air, and therefore very slight differences of pressure at the sea level. The necessity for the further conditions is hence also evident. It will be seen that these conditions were fulfilled in the case of both storms, more completely (as might have been anticipated) in the case of the second storm, when the south-west monsoon current was weaker than it was at the time of the first storm. The history and discussion thus fully bear out the existence of the conditions immediately antecedent to the two storms which the condensation theory asserts to be necessary for the initiation and generation of a cyclonic storm in the Bay. The preceding remarks hence indicate that the energy given out during the process of aqueous vapour condensation on the large scale is the motive power of cyclones, and that the rainfall must be localized and concentrated over a considerable area, for a period of one or more days, in order to produce the continuous and rapid accumulation of energy which characterizes a large cyclonic disturbance. Experience has also shown that the conditions which the condensation theory suggests as being essential for the occurrence of continuous and prolonged local rainfall over a portion of the Bay are exactly those which are present before and during all cyclonic storms in the Bay of Bengal, and that they are more fully marked before the occurrence of the larger than of the smaller cyclones of the Bay. It is, moreover, these antecedent conditions which form the only test or indication of the possible or probable early formation of cyclones in the Bay, and which are utilized in the preparation of the daily weather Reports issued by the India and Bengal Meteorolo- gical Departments. 186 J. Hliot—The South-West Monsoon Storms of the Bay of Bengal. EXPLANATION OF PLATES II—X. The plates give the weather charts for each day during the whole period covered by the two storms of 1883 described in the preceding pages. The curved lines or isobars indicate the distribution of pressure. Along any one of these lines, the estimated air pressure at the sea-level (as determined from the reading of the barometer) is the same. Hence no change of pressure occurs along these lines, and the change of pressure is greatest perpendicularly across these lines. The rate of change is most rapid where the lines are nearest together. As the difference of air pressure between consecutive lines is the same, the rate of increase or decrease of pressure is inversely proportional to the distance between consecutive lines. The isobars form closed curves about the centre of a cyclonic disturbance. Hence the position of the cyclonic vortex on any day is at once determined by an inspection of the charts. The probable path is determined by joining these positions by lines. The direction of the air motion near the earth’s surface is determined by the winds, which are shown by arrows flying with the wind, or pointing to the direction towards which the moving air is advancing. Small circles ( 0 ) indicate a calm at the hour of observation. The charts give the distribution of pressure and wind directions at 10 A. M. of each day. They are based on the 10 A. M. observations taken at the land meteoro- logical stations, and on the 8 A. M. or noon observations taken on board the ships which have furnished logs of the weather experienced by them in the Bay during either storm, allowance being made, wherever at is possible, for the difference of time between the two sets of observations. BOLI O00 OO OO OIE OOOO JOURNAL OF THE ASIATIC SOCIETY OF BENGAL. — Part I1—NATURAL SCIENCE. No. III.—1884. eee IV.—Some Rough Notes for the Construction of a Chapter in the History of the Harth—By R. D. Otpuam, A. R.S. M., Assistant-Superinten- dent, Geological Survey of India. [Received Aug. 30th ;—Read Sept. 3rd, 1884. ] To the coal-miner, or to the mere geological surveyor, the exact corre- lation of the rocks in different parts of the world is of little importance. Little does the mine-owner reck of whether his coal does or does not be- long to the carboniferous era so long as it is saleable at a profit, nor need the geologist, asked to survey and report on a coalfield, trouble his head about this; but, to one who would unravel the physics or the history of the earth, the solution of this problem may well be of paramount impor- tance, though unfortunately often impossible of attainment; generally, one might almost say always, he has to depend on fossils, but the answers these give are often contradictory or Delphic in their obscurity; at no time should they be too literally interpreted, but, like the cutcherry gong in an Indian station, must be made the most of as the only available substitute for a more accurate timepiece. But just as in this city where there are many thousand timepieces of various descrip- tions, of which probably no two keep identical time, every day the time- ball falls and the signal gun is fired to let all who may be concerned know that it is one o’clock; so in the past time-signals have been given throughout the earth, by which we can determine the contemporaneity of the strata in which their records have been preserved. Of this nature would be a wide spread glacial epoch comparable to that which in the 25 188 R. D. Oldham—Some Rough Notes for the [No. 3, recent past has affected both hemispheres of the globe, but, as there is reason to believe that such have occurred at various periods in the history of the earth, we are dependent on the otherwise less accurate paleontological evidence for determining whether the strata shewing signs of glacial action can have been deposited at the same period or must belong to widely separated geological epochs. There can be no doubt that of all forms of paleontological evidence the most trustworthy is that afforded by the marine mollusca. Inha- biting as they do an element of more uniform temperature, and of which every part is in continuous if circuitous connection with the rest, it is but natural that they should be more uniform in character than the fauna of the land, while the simplicity of their structure, greater than that found among vertebrates or higher invertebrates, renders them less lable to change through alteration of the conditions under which they live. On the other hand, this very stability of organism renders them useless for the exact correlation of strata far separated from each other ; for mere determination of homotaxy, even did this exist in the sense in which the term was originally intended to bear, would be but of little value to the physical geologist, to whom the terms ‘Jurassic’ or ‘ Carbonifer- ous,’ if determined merely on paleontological grounds, are as meaningless, for determination of dates in the history of the earth, as the analogous terms ‘Stone Age’ and ‘ Bronze Age’ are for determining periods in the history of the human race. But, if the evidence afforded by marine mollusca is not sufficiently accurate and trustworthy, how much more is this true of that afforded by the terrestrial fauna and flora. True, the duration of the existence of a species Of cycad, conifer, and, possibly, even a fern may be shorter on the average than that of a species of mollusc, and to this extent it may be a more accurate index of contemporaneity ; but it is comparatively seldom that identical species are found in far separated deposits, and paleontologists have consequently to depend mainly on what are called ‘allied species.” Now the hard parts of animals, which in almost every case are all that are preserved to us, give, for the most part, a very true and real indication of the affinity of the animal to which they belonged, while, from the leaf of a tree or the frond—generally barren or with the fructification obliterated in fossilization—of a fern, little or nothing can be gleaned of the relationship of the plant to which it origi- nally belonged ; thus no one would doubt that two specimens of Terebra- tula or Ammonite, declared by a competent paleontologist to belong to the same species, would, if we could recover their soft parts, still prove to belong to the same or very closely allied species, while, on the other hand, we have lately been informed, by a paleeobotanist whose competence none 4 1844.] Construction of a Chapter in the History of the Earth. 189 can doubt, that the Indian and Australian forms of the celebrated Glossopteris browniana, long believed to belong to the same species, differ so widely in their fructification that it is doubtful whether they 2 can be included in the same family, and that they must certainly belong to different genera.* : As an instance of uncertainty of paleontological evidence, I need only quote the well-known case of the Umia and Katrol beds of Kutch, where beds containing a flora with a well-marked Lower Oolite facies overlie other beds in which the fauna is equally distinctly Upper Oolite in type ; another case that might be quoted is that of the Rajmahal and Damuda floras ; in the Rajmahal flora, there are, out of 47 speciesf in all, 26 which are identical with or allied tof European species: of these, fifteen are represented in the Rhetic beds of Hurope, one species being hardly distinguishable from the European form: seven are represented by Paleozoic species, two belonging to an exclusively Paleozoic genus (EZremopteris), while another (Macroteniopteris lata) is, on Dr. Feistman- tel’s own admission, so like the Permian Teniopteris abnormis as to be almost undistinguishable : two species only are allied to Liassic forms, and of these one is also represented in the Rheetic: five species are re- presented in the Lower Oolite of Europe, two by identical forms, while, of the other three, one is also related to a Carboniferous, and the other two to Rheetic, species. From this, an impartial observer would be in- clined to place the flora as certainly not later than Rheetic, but, as on this point the talented paleontologist of the Geological Survey has expressed a very positive opinion that the flora is Liassic in facies, I must perforce * Paleontologia Indica, Fossil Flora of the Lower Gondwanas, Vol. III, p. 103 In this connection, I may quote Dr. Feistmantel as follows :—after noting the difference in the fructification of the two forms, he adds ‘so that I would be quite justified in placing these in a separate genus altogether and thus disposing of the difficulty in determining the age of our Damuda series owing to the correlation of the Indian Australian species.” An easy way of ‘ disposing of the difficulty’ forsooth, but my colleague can hardly have perceived the full force of these words when he penned them, for, carried to their legitimate conclusion, they cut away the ground on which alone palzobotanists can base their claim for the acceptance of fossil plants as a means of correlating distant deposits. The lesson to be learnt is rather that the conclusions of even the ablest paleobotanists must, owing to the nature of the material they have to work with, be received with caution, and that generic and specifio names of fossil plants do not necessarily represent any real affinity, and that in some cases the latter and in most cases the former are names merely and nothing more. + Here and elsewhere, except where the reverse is distinctly stated, I owe my palzontological facts to Dr. O. Feistmantel’s writings in the publications of the Geological Survey of India. t I use this term in the same sense as it is used by paleobotanists ; it may well be that some of these ‘ allied species’ have no real connection with each other, 190 R. D. Oldham—Some Rough Notes for the — [No B bow to his opinion, a feat I can the more easily perform that the exact determination of the age of the Rajmahal series is irrelevant to my present purpose, this being merely to point out that the flora, judged by European standards, is of an extremely heterogeneous character. Turning now to the Damudas, we find that, out of a total 63 species, only twenty shew any affinity to Huropean forms : of these, six are repre- sented by Rheetic species, two of which are identical in Europe and in India: eight are represented in Jurassic beds, one being identical with a species from the Yorkshire Oolite, and two have their nearest allies among living forms: while, of those which are related to species older than the Rhetic, two are represented in the Permian, and two only are repre- sented by allied species in the Trias. The flora of the Damudas is thus seen to be as heterogeneous in its character as that of the Rajmahals and, like that of the latter, would naturally be attributed to a Rheetic age, yet the two series are not merely separated by a break in the stratification, but the two floras are so contrasted in their characters that, whereas the Damuda flora is almost exclusively composed of ferns, that of the Raj- mahals is markedly the preponderance of cycads, and, of all the Rajma- hal species, three only are represented in the Damudas and those by “allied species.”’ These beds have been classed by Dr. Feistmantel as Triassic, and the probabilities in favour of their bemg contemporaneous in the Trias of Europe are about the same as those in favour of a Liassic age for the Rajmahals or a Rheetic age for either of the two, but this is all that can safely be said. Turning now to the Kach flora, which, whether we judge from the associated marine fauna or from the flora itself, is of Oolitic age, we find, out of a total of 27 (excluding Alge) species, 18 are represented by identical or allied species in Hurope, four are identical with Huropean Oolitic species, of which, however, one ranges down to the Rheetic, nine more forms are related to Huropean Oolitic species, while four only are related to species older than the Oolite and in two cases at least the re- lationship is not very close; we have here, then, a much closer relation with a definite Huropean flora than is the case with the Damuda and Rajmahal beds, and this, as I shall presently shew, is of considerable im- portance in unravelling the history of the Gondwana age. In Australia, there is a series of plant-bearing beds whose flora shews many affinities with that of the Indian Gondwanas, but which range over a more extensive period of time, and are marked, both at their upper and at their lower limits, by the association of the plants with marine fossils.* * Conf. principally Rev. W. B. Clarke, Remarks on the Sedimentary forma- tions of New South Wales, 4th edition, and Dr. O. Feistmantel in Palwontographica, 1878 (Appendix). Fi Ei = ted ? oe Pee ee eee ee Sethe Oe | 1884.) Construction of a Chapter in the History of the Earth. 191 ;. ’ At the base of the series, are beds whose marine fauna indicates a _ Devonian age; above these, come beds which contain a flora consisting _ principally of such genera as Lepidodendron, Rhacopteris, and Calamites, ~ among which occurs a single species of Glossopteris.* Above these, but _ still below beds in which a marine fauna of Carboniferous type is found, there is a flora which, judged by Huropean standards, is Mezozoic in facies. At the top of the Newcastle series, to which the beds just men- tioned belong, a more abundant flora is found, which presents many re- lationships to that of our Indian Damudas: in both, Gilossopteris is a do- minant type, both contain the Gilossopteris browniana and two other species allied to Damuda forms: Sphenopteris, which in the New- castle beds is represented by six species, is only represented in the Damudas by one (S. polymorpha, Fstm.), which, however, is said to be more closely allied to the Australian 8. alata than to any Huropean form: the only species of Phyllotheca is allied to the Damuda P. indica, and the common occurrence of Vertebraria in both is another link. That this relationship is not so close as was at one time believed, I readily admit, but nevertheless the relationship is real, and, though it may be presumptuous to express an opinion at variance with that of the talented paleontologist of the Geological Survey of India, I must say that to me the relationship seems far closer than that which unites the Damudas to the Trias of Kurope. Above the Newcastle beds, come the Hawskbury beds, which have yielded but two species of ferns, one of which (Sphenopteris alata, Bgt.), however, is allied toa Damuda species. Above the Hawksbury, come the Wianamatta beds, which have yielded six species of plants, no less than three of which are allied to Damuda forms. It is thus evidently impossible to correlate, on paleontological grounds alone, these beds directly with any of our Indian horizons, but, like the Indian Talchirs, the Hawksbury beds contain certain beds of fine clay through which boulders of all sizes are scattered promiscuously in a manner that can only be attributed to the agency of floating ice. In Victoria, there are beds which similarly indicate the existence of a severe climate at the time of their deposition, and these—the Bacchus Marsh beds —have yielded three species of Gangamopteris, of which one is identical with, and the other two are closely allied to, Talchir species. The Bacchus Marsh beds have not yielded a single species common to themselves and to the Hawksbury beds, but this is of little importance, as it is impossible to suppose that the entire flora of the Bacchus Marsh period consisted * There is some doubt attaching to the correctness of this statement. The Glossopteris was obtained from a different locality and possibly from a newer series of beds than the others. 192 R. D. Oldham—Some Rough Notes for the [No. 3, of three species of Gangamopteris, or that of the Hawksbury period to have been limited to two species of ferns. But, if not directly referable to the same epoch by their contained fossils, there can be no doubt that they are on the same horizon, for, in the uppermost beds of the Newcastle series, two species of Gangamopteris are found, one identical with, and the other allied to, species from the Bacchus Marsh sandstones of Victoria, while the beds above the Hawksbury series in New South Wales can be correlated with those which overlie the Bacchus Marsh beds in Victoria by the occurrence of Pecopteris australis, Morr. and Tenopteris daintreet, McCoy in both. The presence of beds indicating glacial action in both and the absence of similar beds in the associated strata further prove their absolute contemporaneity ; and by an extension of the same reasoning we may assign the Talchirs of India to the same glacial epoch. The paleontological relations of the Gondwanas with the Karoo and Uitenhage series of South Africa are much simpler than with the Austra- lian formations. From the upper part of the Karoo beds, which uncon- formably overlie strata containing an Upper Paleozoic fauna, a limited flora of but five species has been obtained. Of these five, one is Glossopteris brow- niana, another, Dictyopteris ? simplex, Tate, 1s, according to Dr. Feist- mantel, allied to Glossopteris damudica, Fstm., and Rubidgea mackayi is, on the same authority, probably a Gangamopteris ; in addition to these, Tate gives a species of Phyllotheca, but the identification is doubted by Dr. Feistmantel.* Associated with these, there is an abundant and peculiar Reptilian fauna with Dicynodon as a dominant type, a genus not known elsewhere, except from the Panchet subdivision of the Damuda in India. In the overlying Uitenhage series, there is a flora consisting of eleven determinable species ; of these one species of ferns is also found in the Rajmahals, while two, and possibly three, species of ferns and one conifer are closely allied to Rajmahal forms.+ These Uitenhage plants are associated with beds containing an Oolitic marine fauna. The paleonto- logy of these beds sufficiently indicates a parallelism with the Gond- wanas, and, in confirmation of this, we find, at the base of the Karoo series, an undisputably glacial boulder bed,f which we shall be justified in assigning to the same epoch as those of the Talchirs in India and of the Hawksbury and Bacchus Marsh beds in Australia. Viewing these circumstances, there can, I think, be no doubt that these glacial boulder clays of Africa, India, and Australia represent one and the same epoch in the history of the earth and are, as strictly as the word can be applied, of contemporaneous, if not absolutely coeval, origin. Q. J. G. S., XXIII, 140, Palwontographica, 1878, p. 114, * + Q. J. G.8., XXIII, p. 140. t Q.J.G.S., XXVII, 58 and 535. * 1884.] Construction of a Chapter in the History of the Earth. 193 And further, as in every case the paleontological evidence indicates that _ these glacial beds are of late Paleozoic or early Secondary age, I think - itis probable that, as has been suggested by Mr. H. F. Blanford, they are of the same age as the Permian boulder clays of Hurope.* Having thus obtained a common era in the geological history of these three countries (India, Africa, and Australia), we are able to examine their history in an intelligent manner. The first thing noticeable is that, in Australia, at a period corresponding fairly to the Devonian, both the fauna and the flora were, judged by European standards, of a Paleozoic type. Later on, probably in Lower Carboniferous times, there appears, among species of Lepidodendron, Rhacopteris, and Calamites, which, in Kurope, are found in rocks of Carboniferous age, a single species of Glossopteris, the forerunner of a newer flora destined to supplant the olderforms. In the Newcastle (Upper Carboniferous) beds, this flora has completely eusted the older forms, and, as I have already noticed, shews considerable relationship to that of the Damudas in India. Yet, if the Talchirs and the Bacchus Marsh beds are really of contemporaneous origin as was first suggested by Dr. Feistmantel, and if the Bacchus Marsh and Hawskbury beds are also contemporaneous (and the presence of traces of glacial action in all three is at least presumptive evidence in favour of this conclusion), the Damudas must be of very much later date than the Newcastle beds, and we have to explain why it is that the Newcastle flora left Australia when it did, and why it or its descen- dants lingered on in India, and, as I propose to shew, spread over what is now the Old World producing important modifications in its flora. It is possible to suppose that the Newcastle flora required a warm —though from internal evidence one would rather look upon it as indi- cating a cool temperate—climate ; that, on the advent of more severe con- ditions, it migrated towards the Equator and remained there, not merely through a period of extreme severity, but through a further period, when the climate was cooler than it had been during the deposition of the Newcastle beds, and during which a flora more suited to the latitude flourished in Australia. But there are so many objections to this hypo- thesis that it can hardly ‘be tenable, and, however wild my alternative hypothesis may be thought, I hope to prove that it is really the more probable of the two. In the first place, we have to account for the prevalence of glacial conditions at a low level in India even within the tropics. This was not paralleled during the last glacial period, for even the erratics of the Petwar are 10 degrees beyond the tropics and 2,000 feet above the level * This correlation of the Indian, African, and European boulder beds has been suggested by Mr. H. F. Blanford, Q. J. G.8., XXI, p. 519. 194 R. D. Oldham—Some Rough Notes for the [No. 3, of the sea, while the Petwar was certainly not less elevated during the glacial period than it is now. Further, the glacial deposits in India are far better developed, and, to judge from the descriptions, must be far thicker and represent a much longer period of time during which the climate was severe than those in Australia. Yet the glacial deposits of New South Wales are 10° further from the Equator than the Indian, so that, if we might shift the Equator some 10° further south between India and Australia, observed facts would be more in accordance with what one would expect than can be the case if we are compelled to assume the Equator fixed throughout all time. But, if we try to compare the facts observed in Australia and beta we are landed in astill greater difficulty, for, lying as they do on about the same parallel of South Latitude, the glacial beds are more strongly de- veloped in Africa even than in India ;. and, as we can hardly suppose the greater severity of climate to be due to altitude, it must have been due to latitude, to obtain which we must suppose that that portion of the Karth’s crust which now forms South Africa then lay in a higher latitude than that which is now Australia ; in other words, the comparison of the Permian (?) glacial beds of Africa and Australia, as in the case of Australia and India, points to the conclusion, either that there has been a change in the position of the axis of revolution of the earth, or, what is more probable, that the crust of the earth then occupied a position relative to the central nucleus different from that which it now does. An experiment with a globe will shew that the relations of India, Australia, and Africa indicated above, viz., that Central India was in a higher latitude than New South Wales and South Africa in a higher latitude than either, are best satisfied by taking the Equator between India and Australia, but nearer the latter than is now the case, and thence through a point lying between the Cape of Good Hope and the South Pole in not less than 70° of South Latitude; a disposition which would bring some point in Central Africa over one of the poles. Turning now from these physical and climatic arguments to those derivable from palzontology, I hope to shew that they lead to the same conclusions. I have already referred to the fact that the Damuda and Rajmahal floras of India shew affinities with those of almost every division of the Mezozoic era in Hurope, and I would now draw attention to the fact that those species which are related to upper Secondary forms in Europe belong very largely to types which first appear in the Palzozoic beds of Australia. Foremost among these, of course, are Glossopteris, Phyllo- theca, and Vertebraria ; not known in Europe before Jurassic times, these were certainly living in Australia at the commencement of the Carboni- ferous epoch. Pecopteris, Thinnfeldia, Gangamopteris, Neggerathiopsis 1884.] Construction of a Chapter in the History of the Earth. 195 _ likewise are found in the Newcastle series of New South Wales, but in _ Europe only in Secondary beds. Allowing that some of these genera are purely artificial, and that the species grouped under them may not really be allied in every case, it is on the other hand probable that _ some forms placed under distinct genera should properly be united with some of those grouped under the genera above mentioned, and, making the most liberal deduction for the value or want of value of negative evidence, I think that there is still a very considerable weight of pro- bability, on this count alone, in favour of a newer type of vegetation haying originated in Australia in Paleozoic times and im the Permian period commenced to spread over the rest of the world. The explanation seems to be that, on the advent of the Glacial period, the flora, which had supplanted the older types in Australia, was driven towards the Equator. As the climate ameliorated, it did not again retreat towards Australia, either because its place was taken by newer species, or, more probably, because, owing to changes in the distri- bution of land and water, it could no longer do so, but to the north—or what for convenience we may provisionally call the north,—of the Equator it lived on in what is now India and, gradually spreading over the hemisphere, produced a profound modification in the pre-existing floras of what we now know as the Old World. The flora of the Wianamatta beds, as I have explained, shews a certain relationship with that of the Damudas, but none with that of the Newcastle beds as far as species go; of the genera, however, three out of the six, or, if we include the Hawksbury beds, four out of seven are also found in the Newcastle beds. The beds newer than the Wianamattas have yielded a flora consisting of nine species belonging to seven genera, of which, if we except the Phyllotheca australis, only one species is allied to an Indian form, viz., Pecopteris australis, Morr. allied to P. indica, Oldh. and Morr. from the Rajmahals. We have here a distinct decline in _ the closeness of relationship between the Indian and Australian floras, and, though, of course, this might be due to the imperfection of the record, the probabilities are against its being entirely due to that cause, and we may safely conclude that some barrier separated the two areas, by which the floras of India and Australia were kept apart and followed separate and consequently diverging lines of descent. Turning now fora while to South Africa, I must commence by declar- ing it as my opinion that the relationships between the Indian and African floras of the periods I am discussing are with difficulty explicable, unless it is granted that there was in those days a continent, or at any rate a conti- nuous chain of islands, stretching from South Africa towards India. I am aware that Mr. A. R. Wallace has declared such to be uncalled for and 26 196 R. D. Oldham—Some Rough Notes for the [No. 3, impossible to grant,* and I am ready to admit that the facts of distri- bution of animals as detailed by him are conclusive against the possibi- lity of such a distribution of land and water, at any rate since the Miocene period. But there is no reason to suppose that the present distribution of plants or animals can throw any light on the distribution of land and water in late Paleozoic and early Secondary times. On the other hand, in favour - of the land connection, I claim, firstly, that the relationship between the fauna and flora of the Damudas on the one hand and the Karoo beds on the other is far more real and close than the mere ‘ similarity of animal and vegetable productions’ to which Mr. Wallace seems to have considered it to be confined ; secondly, that this relationship of the two floras con- tinued into the Uitenhage and Rajmahal series, which could hardly have been the case had the two areas been as separated then as now; and, thirdly, that the very peculiar relationships and differences between the cretaceous faunas of Central and Southern India on the one hand and Arabia and South Africa on the other are such as imperatively to de- mand the existence of a continuous barrier of dry land stretching be- tween India and Africa. It is needless to expatiate further on this point, for, if such a barrier existed during the Cretaceous period, any argument against its possibility derived from the doctrine of the permanence of continents must fall to the ground, and there remains no reason why, if on independant grounds its existence is shewn to be probable, such a modification as I require may not have existed at the commencement of the Secondary period. That, during the deposition of the Damudas, there was continuous land communication with South Africa I do not suppose, for the very remarkable reptilian fauna, which, like the recent marsupial fauna of Australia, mimicked many of the higher mammalia, points rather to some isolated continental island which was connected with India, as Australia now is with Asia, by a chain of large islands separated by narrow straits, across which the spores of ferns and the seeds of plants could be wafted, but which were impassable to terrestrial reptiles. But even a land connection of this sort would probably be inade- quate by itself to account for the close relationship which the small frag- ment preserved to us of the flora of the Uitenhage period shews to that of the Rajmahals. For it is at least highly probable that the heat of the Equator would be as effectual a barrier as a broad sea, and, if the floras of India and Africa had pursued independent courses of development for a period sufficient for the dying out of every species and almost every genus, and for a change in the facies of the flora from one composed mainly of ferns to one composed mainly of cycads, it is inconceivable that the floras of the Uitenhage and Rajmahal series should exhibit the close * Island Life, p. 398. ~ ee * 1884.] Construction of a Chapter in the History of the Earth. 197 relationships they do. But this difficulty would not exist could we suppose that what are now South Africa and India then lay on the same side of the Equator; and thus the paleontology of these beds, as well as _ their petrology, points towards the conclusion that in early Secondary times the crust of the earth did not occupy the same position with respect to the axis of rotation as it now does. That none of these arguments are conclusive by themselves I ad- mit; I willingly admit that the floras preserved to us represent but a fraction of the species that lived when the beds that have yielded our fossils were being deposited, but the probability is vastly against only those species which were related to each other in the two countries being preserved, and we may, I think, safely argue from the small sample preserved to the larger bulk which is lost. In the same manner, I freely admit that the differences in the severity of climate may have been due to other causes besides difference of latitude, but on the average a colder climate indicates a higher latitude, and, when we find that, from whatever point we approach this matter, we are led towards the same conclusion, it seems to me that there is a very strong presumption in favour of its truth. I fear this paper has already extended to too great a length for me to examine the arguments that have been put forward to prove that any change of latitude is physically impossible, but I cannot conclude without pointing out that what has been proved is that no conceivable elevation or depression of the earth’s surface could produce an appreci- able alteration in the axis of rotation of the earth asa whole. But, though the mathematical reasoning on which this conclusion is based may be unassailable, it has no bearing on the question of whether changes of latitude may not have taken place in the past, except on the assumption that the earth is rigid throughout, and that the crust has no power of sliding over the heated if solid core, an hypothesis which has been ably combated by the Rev. O. Fisher,* and which I hold to be inconsistent with the known facts of stratigraphical geology. While, if the views put forward in this paper are true,—and there seems to me a very strong presumption in their favour,—the crust of the earth must in Mezozoic times have occupied a very different position with reference to the axis of rotation from that which it does at the present day. As yet the only fact which has in any material degree attracted the attention of English geologists is the prevalence during the past of mild climates within what are now the Arctic regions; and hypotheses have been broached to account for this independent of an alteration of the position * Physics of the Earth’s Crust passim ; see particularly p. 184, 198 R. D. Oldham—Some Rough Notes, &c. [No. 3, of the crust relative to the central core of the earth; but the more com- pletely such an hypothesis may explain the absence of any trace of glacia- tion in the Paleozoic, Secondary, or Tertiray rocks of the Arctic regions, to which Baron Nordenskj6ld has drawn our attention, the more irrecon- cileable is it with the repeated traces of glacial action that are met with almost within the tropics. Yet the latter as urgently requires explanation as the former, and I have put these suggestions forward not from any conviction of their intrinsic truth, but because I feel that the rigid bonds within which mathematicians have sought to confine geo- logists must be largely and materially relaxed, because I feel that every addition to the growing pressure against these bonds is of some—even if but small—importance, but chiefly because I trust that I may be instru- mental in drawing the attention of others with greater opportunities and greater abilities to the solution of this problem. P. S.—Just a week before this paper was read Mr. W. T. Blanford, addressing the geological section of the British Association at Montreal, devoted the greater part of his address to the consideration of a subject to which he has before now referred, more particularly in the Records of the Geological Survey of India, and on which I have cursorily touched in the introductory part of this paper; I mean the uncertainty of paleontological evidence in determining the exact correlation of widely separated beds. He also refers to a report on the Stormberg coal-fields by Mr. E. J. Dunne, which I have strangely overlooked : Mr. Dunne mentions the existence of three species of plants in the Stormberg beds identical with Australian species, an identification which, if correct, greatly diminishes, if it does not altogether annihilate, the value of my argument from the relationships between the African and Indian early Secondary floras, but this is of the less importance, as, owing to the known value or want of value of negative evidence in palsonto- logy, little value would in any case attach to an argument of this kind. I )J. WOOD-MASON, Journ. Asiat. Soc. Bengal, 1884, Vol.LIL,Pt IL. PL. XIIL. Sax 2. 4a x 2, BLD. del. J -W-M.dir Mintern. Bros imp . Parker & Coward. hth Genus HESTIAS. Autor del. ’ Mintern. Bros imp . Parker & Coward hth SIMULIUM INDICUM. 1884.] HE. Becher—4A new Species of Simulium from Assam. 199 V.—A new Species of Simulium from Assam.—By Dr. Epwarp Bacuer, Vienna. Communicated and translated by the Natura History SECRETARY. [Received October 13th ;—Read November 5th, 1884. | (With Pl. XIV.) SIMULIUM INDICUM, nov. spec. 9. Caput et thorax brunneo-nigra; thorax convexus, scutellum migrum ; palpi 4-articulati, fusci ; antennae 10-articulatae, fuscae ; alae magnae, latae, nervi costales crassiores quam reliqui ; pedes varti : femora et tibiae in basi flavae, in apice fuscae, tarsi fusct ; abdomen breve, seg- mentum primum latissimum; hoc et triwm sequentium pars ventralis flavicans, cetera subfusca. Longitudo 3 mm. Head free, standing pretty low; brown-black; forehead broad, clypeus short, nearly vertical ; eyes kidney-shaped, with a moderate notch for the reception of the first antennal joint. Ocelli wanting. Antenne dark brown-black, 10-jointed; the second joint distinctly constricted off from, and equal in length to, the first, and longer than the rest; the three succeeding joints broader than long, telescoped into one an- other ; the four next equally long and broad, each tapering to the apex, the last joint pointed at the apex, somewhat longer than the preceding. Proboscis salient, dark; mouth-parts differing in matters of detail only from those of the typical form ; palpi dark, 4-jointed, the basal joints lighter ; the first joint short, the palp-scale resembling it and thus appa- rently representing a fifth joint, the second and the third joints almost of the same length, the fourth 13 times as long as the third, all the joints pretty equally broad and moderately bristly. Thorax brown-black, high-arched, without transverse suture, tergum and scutellum velvet-black, somewhat shining, sides of the thorax lighter, especially near the coxz of the first pair of Jegs. Wings* large and broad, the marginal vein thick, terminating before the apex of the wing, the anterior branch of the first longitudinal vein ¥ clature of the veins of the wings is retained in the following description. According to Adolf’s theory, the veins should, in consideration of Brauer’s work on this subject, be named as follows:—the anterior branch of the first longitudinal vein = the auxiliary vein (Hilfsader) ; the principal branch of the first longitudinal vein = the first longitudinal vein; the small transverse vein = the trunk of the third longitudinal vein’; the third and the fourth longitudinal veins = the third longitn- dinal vein ; the succeeding fold= the fourth longitudinal vein; the fifth and the sixth longitudinal veins = the fifth longitudinal vein ; the fold = the anal vein (Conf. Brauer, Denkschr. d. Kais. Akad. d. Wissen. Wien, Math. Nat. Cl. Bd. xliv, 1882, p. 90, and Wiener Hut. Zeitschr. ii, 1883, Heft 2, p. 27). 27 ; * In order to facilitate comparison with other descriptions, the usual nomen- } ————— eee 200 E. Becher—A new Species of Simulium from Assam. [No. 3, short, scarcely reaching the middle of the wing, the principal branch longer, running out near the third longitudinal vein; the second longi- tudinal vein wanting; the third branching off from the first before the middle, running into the marginal vein far before the apex of the wing ; the three first veins thick and distinct ; the succeeding ones very weak ; the fourth longitudinal vein forked at the so-called small transverse vein, the prongs of the fork hence much longer than the handle, the upper prong slightly bisinuous, the lower almost straight; the fifth vein straight, a little bent outwards ; the sixth strongly bisinuous ; the axillary vein not reaching the hinder margin, slightly sinuous; between the fourth and the fifth veins a straight, very distinct fold; a similar though weaker fold behind the sixth vein. Halteres uncovered, dazzling white. Legs: coxe dark, trochanter long, yellowish; femora and tibie throughout black-brown, metatarsus lighter at the base, a little shorter than the tibia ; all the tibiee with spurs, metatarsus of the third pair of legs notched at the apex (figs. 5, 6), those of the two first pairs trun- cate, spurred; the fourth tarsal joint expanded into a heart-shaped figure; the fifth longish clavate, with long divergent curved bristles, which in the first pair of legs are seated on the third tarsal joint; legs thickly covered with hairs, particularly on the tarsus, ungues small, pulvilli rudimentary. Abdomen short, of eight segments ; the first segment is the broadest and, like the sternal parts of the three succeeding segments, yellowish ; the genital parts a little projecting. The above-described species of Simuliuwm is the first that has yet been made known from Asia, as only a few non-European forms have hitherto been described, whereas the number of European species is not inconsiderable. The larve and the pupe (figs. 11, 12, 13) of the European species live in water; the latter in conical (tuétenartigen) cocoons attached to stones, stalks of grass, confervee, and the like. EXPLANATION OF PLATE XIV. Fig. 1. Simulium indicum, 9, x 8. Fig. 2. Wing x 8. 3a. A leg of the first pair x 15. Fig. 3b. Tarsus of the same leg x 60. Fig. 4a. A leg of the second pair x 15. Fig. 4b. Tarsus of the same x 60. Fig. 5a. A leg of the third pair x 15. Fig. 5b. Tarsus of the same x 60. Fig. 6. Head from in front x 30. Fig. 7. Antenna x 90. 8. Mandible x 90. Fig. 9. Hypopharynx x 90. Fig. 10. Maxilla and palp x 90. Fig. 11. Larva of Simulium ornatum, Mg. x 6. Fig. 12. Pupa of Simuliwm sp. in its conical cocoon. ne mht MM Hit ieamnite SAIURAND GG. °UCHRTEY”cHTNGOAITON rete if | SA NEAEPSOHVG:AVGQV UA SUORSOMIODASUUE } “ST MPT aT aL me ELUTE TTT MAU EAPSVOMEREADOEDSSUEN) UHEUORTEE PATE + LOOK apt a 88 gseee / | ce | | 5 2 | S eo a) : 9 2 o ra $ @ ° - 4 & ra) b ® ®@ 3 » = © u a a 3 & © 4 = Hn ong ee % 1884.] A. N. Pearson—Variations of Rainfall in Northern Indtz. 201 A Vi—Variations of Rainfall in Northern India during the Sunspot 4 : Period.— By A. N. Pearson, Esq., Officiating Meteorological Reporter a for Western India. Communicated by the PRESIDENT. [Received October 6th ;—Read November 5th, 1884. } (With rl, XI.) Mr. S. A. Hill, in his paper on the “ Variations of Rainfall in Northern India,” published in the Indian Meteorological Memoirs, Vol. I, showed very clearly the opposition that exists between the variations of the winter and of the summer rainfall in Northern India during the sunspot period. For the purpose of bringing forward with greater clearness the main points of his investigation, he put the actual rain- fall totals—which, as they stood, showed considerable apparent irregu- larities—through a simple process of smoothing such as is frequently adopted in dealing with statistical tables; and, by so doing, eliminated the apparent irregularities. But it appears to me that the unsmoothed results present points of interest over and above those that are presented by the smoothed results ; that, in fact, the apparently irregular variations are regulated in a very definite manner. In the table here given, I reproduce the general means of Mr. Hill’s Tables II and IV, together with the smoothed results as he gave them in the text. Variations of the Rainfall for each Year of the Hleven Year Cycle in Percentages of the Local Means. Winter Rainfall. Summer Rainfall. - ie aetna Eitchaen eked Year of the a cd 9 A = od Seed yy Cycle. S a 5 5 r-| 3 » - | Be) es q ° Re n eo) tt n (e) | d eo =| A S =| ‘ ss Se a 2 A =) a) A Ist —176 |—171 |— O57] + 08) + 36] — 2:8 2nd = 46 )—136 | + 90) +107) 4+ 74) + +53 3rd —256 | —188 |— 68] + 33) + 98] — 65 4th —195 | —204 | + 09] +4 19°38) + 12°6 + 72 5th —170 |— 78 |— 92+ 74) + 78) — O4 6th 1291 | +231 |— Tr0Ol— 35 |— 56 + 21 7th + 654 | +356 | + 29°38 | —22°7 |} —108/ —11°9 Sth —104 | +157 ; —2611+ 56)— 8l + 13°7 9th +183 | +102 | + 81]—210, —100| —110 | 10th +149 | + 49 | +100]— 36|]— 70| + 34 —149 |—1371+4+ 02|— 06 + 08 11th — 28°6 i ) 1) 202 A. N. Pearson—Variations of Rainfall in Northern [No. 3, The smoothed numbers of the above table are curved in the accom- panying diagram (Pl. XT) in thick continuous lines, under the names ‘“* Winter Rainfall, A” and “ Summer Rainfall, B.’”’ The figures so pro- duced are identical with the curves given by Mr. Hill in his paper. The unsmoothed numbers of the above table are in the diagram superposed in dotted lines upon the smoothed curves. At the bottom of the diagram, T have reproduced the sunspot curve as given by Mr. Hill. On inspecting the smoothed rainfall curves, it will be seen that the winter and the summer curve both agree in showing a single oscillation during the eleven years of the sunspot period; but they differ in the character of that oscillation, for, while the winter rainfall is at its maxi- mum during the year of sunspot minimum, the summer rainfall on the contrary is then ata minimum. This is the main fact pointed out in the paper above quoted. On inspecting the actual figures, however,—the unsmoothed num- bers in the above table and the dotted curves A and B of the dia- gram—it will be seen that, besides this eleven yearly oscillation, both the winter and the summer rainfall show several variations of minor period such as one might naturally suppose to be accidental ; thus the winter rainfall shows three distinct maxima, one in the 2nd year of the sunspot cycle, one in the 7th year, and one in the 9th and 10th, and shows marked minima in the 3rd, 8th, and 11th years ; while the summer rainfall has maxima in the 2nd, 4th, and 8th years and minima in the 8rd, 7th, and 9th. It is to these minor period oscillations that I wish in this short paper to call attention. And, in order that they may present themselves in a more convenient form for study, I have separated them from the eleven yearly oscillation by the simple method of subtracting the smoothed numbers in the above table from the unsmoothed. The differences are curved in the diagram under the name “ Minor Oscilla- tions of A and B,” the winter oscillations being given in dot-and-dash lines, and the summer in simple dotted lines. Confining attention to these ‘‘ minor oscillations ”’ curves, it will be noticed that, in those years which at the foot of the diagram are marked +, and which are years of maximum sunspot, the short period oscilla- tions in the winter and the summer rainfall are of the same character, that is to say, that when there is more winter rain there is more summer rain, and when there is less of the one there is less of the other also. But it will be seen that, in those years which at the foot of the diagram are marked —, and which are years of minimum sunspot, the short period oscillations in the winter rainfall are of opposite character to those in the summer rainfall, that when there is more rain in the winter there a 1884.) India during the Sunspot Period. 203 is less during the summer, and vice versd. Again, in those years which _ in the diagram are marked +, and which immediately precede the _ years of sunspot maximum and minimum, the order above pointed out obtains only in a slight degree ; in other words, these are years of transi- tion. ‘ That these facts are purely the result of accident seems very un- likely, for they are supported by three other series of concurrent facts ; which are as follow :— lst. The plus years begin immediately after the sunspot maxima, and the minus years begin immediately at the sunspot minimum. 2nd. There are more transition years during the slow descent of the sunspot curve than during its rapid ascent. 3rd. The oscillations of both the winter and the summer rainfall are of greater amplitude during the negative years than during the positive. With reference to the first of the above series of facts, it might be supposed that, as the minus years begin immediately at the sunspot mini- - mum, so for perfect analogy the plus years should begin immediately at the sunspot maximum. But this is by no means necessary, for the slight delay in the coming in of the positive years agrees very well with the slow descent of the sunspot curve as compared with its rapid ascent. The main fact which I have pointed out in this paper,—namely, that the smaller variations of the winter rainfall are the same in character as those of the summer rainfall during years of maximum sunspot; and opposite in character during years of minimum sunspot,—if it can be established as a general rule, will be an important one; for it will indicate that, whatever be the cause which produces the general opposi- tion in character between the eleven yearly variations of the winter and of the summer rainfalls, that cause operates chiefly during the years of minimum sunspot, and during three years of maximum sunspot it operates only in a very minor degree, and in two of those years (namely, the 1st and 2nd) it probably does not operate at all. By thus limiting the period during which the cause operates, a valuable point is gained, and a clue to a knowledge of the cause possibly afforded. It is also interesting to notice that not only do the rules above in- dicated obtain qualitatively, but that there is also a near approach to a quantitative relation between the short period oscillations of the summer and the winter rainfall respectively. The nature of this relation in the years which I have denoted as positive, namely, in the lst, 2nd, and 3rd years of the sunspot cycle, will be seen at once on inspecting the “ minor oscillations” curve of the diagram. It will be observed that the oscil- lation which takes place in the two curves during those three years is not only the same in phase, but is nearly the same in amplitude. The LS a PR OS gO ee ee her ae SO ae ey eS Me at Ve, a 204 selta, 38 < taooana, 43 * vidura, 36 zeta, 41 Amyna selenampha, 236 Anaxarcha, 206 Anophia olivescens, 236 *A phendala divaricata, 235 Aphnzous, 25, 27 » concanus, 27 5 himalayanus, 26 ¢ lazularius, 27 * “i lilacinus, 28 _ lohita, 26, 27 - lunulifer, 28, 251 * lunulifera, 251 » nipalicus, 27 & orissanus, 7b. < peguanus, 26, ib. 33 » khurdanns, ib., 27 INDEX. Ras Names of New Genera and Species have an asterisk (*) prefixed. ~~ *Aphneous tigrinus, 25 ” trifurcatus, 26, 27 fas vulcanus, 25 + ‘ zebrinus, 28 zoilus, ib. Appias, 46 » amboides, ib. *Apporasa, 38 Ae atkinsoni, ib. Apurima xanthogastrella, 237 Argiva hieroglyphica, 236 Argyris ocellata, 237 Arhopala chinensis, 41 Artaxa subfasciata, 235 Astura punctiferalis, 237 Athyrma, 236 Barsine conjunctana, 235 » gratiosa, ib. » tessellata, ib. Bizone bianca, ib. Bombyces, 234 Buzura multipunctaria, 237 Calamites, 191, 193 Calesia hemorrhoda, 236 Callyna jaguaria, ib. Calymnia panopns, 234 Catophaga, 43 ps neombo, 7b. pA paulina, 44 % An roepstorfiii, ib. * is wardii, 43 Cephaloxys lacteipennis, 233 r locusta, ib. + quadrimacula, ib. terpsichore, ib. Chalcosia argentata, 234 *Chliaria, 32 ai cachara, 33 + chandrana, 2b. x eltola, ib. a kina, ib. - nilgirica, 7b. othona, ib. Chosradodis, 238, 239 Bs brunneri, 238, 241 ” cancellata, 238, 239, 243 a laticollis, 241, 243 is peruviana, 240 [243 ag rhombicollis, 238, ib., 241, 246 Choeradodis rhomboidea, 238, 241, 242, 243 s servillei, 238, 240, 241 xs squilla, 238, 243 ” stalii, 242 strumaria, 238, 239, 240, 241 ,Chrysophanus, 25 is baralacha, 7b. » phleeas, ib. ” stygianus, ib, Cicada, 229 phage. » affinis, 211 » anea, 229 » apicalis, 231 » aurata, 230 » crocea, 220 ” ferruginea, 230 » flavida, 226, 227 » guttularis, 227 » hemiptera, 215 » immaculata, 231 » imperatoria, 229 » indica, 217 » intermedia, 231 » maculata, 222 » maculicollis, 230 » mannifera, 223 » mearesiana, 217 » nobilis, 215 » obtecta, 226 » octonotata, 221 » oOperculata, 231 » percheronii, 222 », pheenicura, 219 » philemata, 218 », pulchella, 223 », Sanguinea, 218 » sanguinoleta, ib. » Speciosa, 217 » spinosa, 227 ” splendidula, 220 » subtincta, 229 » subvitta, 230 » sulphurea, 223 » testacea, 219 » thalassina, 222 » trabeata, 219 » vacina, 231 » . vaginata, 223 » Varians, 226 » vicina, 230 » virescens, 223 xantes, 230 Cicadides, 210 Cirrhochroa, 19 = abnormis, 1b. *Cophanta, 35 i illurgis, ib., 36 maculata, 36 Cosmopsaltria, 225, 226, 228 abdulla, 226, 227 +E) *Cupitha, 47 : Index. Cosmopsaltria doryca, 226, 227 os durga, 226 ne flavida, 227 - obtecta, 226 e oopaga, 227 os sita, 226, 228 spinosa, 226, 227 Crambices, 237 Creatonotus diminuta, 235 Cricula trifenestrata, ib. Cryptotympana, 230 atrata, 231 Ps immaculata, 1b. * intermedia, 7b. of recta, 230 vicina, 1b. purreea, 48 mes tympanifera, ib. Cyclosia panthona, 234 9 papilionaris, 1b. *Dacalana, 36 * * burmana, ib. a cotys, vb. a vidura, ib. *Darasana, 42 * + newara, 1b. = perimuta, ib. Deudorix nasaka, 34 *Devanica bicolor, 235 is risa, 1b. Diceropygia, 226 Dictyopteris P simplex, 192 Dicynodon, 1b. Dipsas malika, 34 Dreata testacea, 235 EE ee, 31 ‘ boisduvalii, tigrina, 224 Dundubia tripurasura, 225, 226 Fes urania, 228 Ad vaginata, 223 s varians, 226 ° vibrans, 224, 225, ib., 228 Elphos scolopaica, 237 Emathia, 229 “A zegrota, ib. Eremopteris, 189 Ergolis, 19 » ariadne, 20 mi y5- indica, 4b. » merione, 19, ib. * , tapestrina, 19 Erynnis, 51 as alces, ib. Eterusia risa, 235 *Euaspa, 29 » miliona, 1b. 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The exact period of publication cannot be guaranteed, nor the — precise cost of the total work, bat every effort will be made to complete the publica- — tion within three years at the outside, and to keep the cost within Re. 60 for the — entire work. ‘ * PUBLISHED BY THE CALCUTTA CENTRAL PRESS COMPANY, LIMITED, 5, CounciL House STReEeEr. aa NEW SERIES. VOL. LIII, CCLXII. \ ee JOURNAL -ASIATIC SOCIETY OF BENGAL. Vol. LIII, Part II, No. III.—1884. EDITED BY que Natura. flIsTORY PECRETARY. : within these limits its inquiries will be extended to whatever is performed by man, or produced by nature.”—Sir WILLIAM JONES. > ‘S ae “The bounds of its investigation will be the geographical limits of Asia: and *,* Communications should be sent under cover to the Secretaries, Asiat. Soc., to whom all orders for the work are to be addressed in India; or, in Lon- af don, care of Messrs. Triibner and Co., 57 ¥ 59, Ludgate Hill. \ 4 eee in LON ee ee CALCUTTA: Pears BY }. y. J HOMAS, AT THE PAPTIST Mission PRESS, Th AND PUBLISHED BY THE Vy ASIATIC SOCIETY, 57, PARK STREET, | | } 1884. e ’ S) ' S 2 ESS AER SCO am: ee ee eee ow a Prise Gictaitee of postage) to Subscribers, Rs. 1-8.——To Non-Subscriters Bs, 2 - ; Price in England, 4 Shillings -_ Issued April 22nd, 1885. CONTENTS. a TV .—Some Rough Notes for the Construction of a Chapter in the History of the Earth—By R. D. Otpnam, A. R. S. M.,, Assistant Superintendent, Geological Survey of India, .orss.cveses V.—A new Species of Simulium from Assam.—By Dr. Epwarp Becuer, Vienna. Communicated and translated by the Na- TURAL History Secretary (With Plate XIV), .........c..c05 V1I—Variations of Rainfall in Northern India during the Sinipok Period—By A. N. Prarson, Esq., Officiating Meteorological Reporter for Western India. stints mieten the PRESIDENT (With Plate XI), .........ss00. th ssacvoane ~ Page | 187 199 201 VII.—Description of a new Lipdeptsiane teed iy to the © Heterocerous Genus Trabala.—By F. 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J HOMaS, AT THE PAPTISF Mission PREss, x AND PUBLISHED BY THE , ASIATIC SOCIETY, 57, PARK STREET, } t ~ -e SES 2 ooo a», SS 4 Price (exclusive of postage) to Subscribers, Rs 1-8.—To Non-Subscribers Rs. 2 Price in England, 4 Shillings, © 2 Issued Feb. 3rd, 1887. CONTENTS. . v7 | Page PNGSES y orssateeeties tects r Avs Syd avila eas duandgaet id iaase chit aaa Title and List of Contributors. CONTENTS OF THE NATURAL HISTORY PART (PT. Il.) OF THE - AOURNAL OF THE ASIATIC SOCIETY OF BENGAL FOR 1883. Exh BNO! E: dias’ Unione 24th, 1883). Description of a new Species of "the Rhopalocerous Genus Cyrestis from the Great Nicobar. (With Pl. 1.) : —By Lionet pe Nicn’yittz. On the Measurement of Solar Radiation by means of the Black-buib Thermometer in vacuo.—By S. A. Hitt, ae eB, Se., Metl. Rep. to N. W. P. and Oudh. Notes of a Trip up the Dihing ren Basin to Dopha Pani, §c., January and February, 1882. (With Pls. II ; - ; ee VI.)—By S. E. Puat. 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