throughout to give me the sole, or, at any rate, the chief, responsibility for both hypothesis and examples. In writing my book I made great use of a very interesting series of specimens in the Museum of the Royal College of Surgeons, lately brought together by Prof. Stewart. The aggressive mimicry of the Volucella was illustrated in one of these cases, and I briefly described the contents of the case in the passage Mr. Bateson quotes. I was glad to give a few more details than those supplied by Mr. Wallace, and at the same time to mention examples which could be actually seen by readers; for I referred to the collection more than once. I was, however, anxious to obtain confirmation from one who had studied the Hymenoptera and their parasites much more minutely than I had, so I referred the proofs to Mr. R. C. L. Perkins, a most observant naturalist, specially interested in these insects. He made some valuable suggestions, but did not modify the account of the case in the Royal College of Surgeons. I think I may claim, therefore, that I took all reasonable precautions to avoid error in a part of the subject which had not then come under my own personal observation. Prof. Lloyd Morgan, in his interesting "Animal Life and Intelligence," has also mentioned this example, and figures the Volucella and Bombus muscorum. He tells me that his figures were copied from a case in the Natural History Museum, so that my selection appears to be supported by the two great biological museums of London. Within a few weeks of the appearance of my book, I had found out the omission of the other banded humble-bees also mimicked by the mystacea variety of Volucella bombylans, and I showed one of these (I think B. hortorum) at a lecture given to the British Association at Leeds in 1890. I had intended, and intend, to repair the omission in any reprint that may be required. There is, however, nothing inaccurate in the statement that B. muscorum is mimicked. We require something more than dogmatic assertions and question-begging metaphor of tabby-cat and fox to establish this as an error of the two museums and the two volumes which have followed them in this respect. Mr. Bateson appears to have been studying the literature of Volucella rather carefully: if he now extends his investigations to the perfect insects themselves, and compares the individuals in a series of moderate length, he will find that the mystacea variety differs much in the demarcation of its rings or zones, and also that the appearance of each individual varies with the direction from which it is observed. The less sharply-marked appearances resemble B. muscorum, the likeness being increased by a slight indication of zoning to be seen in the latter. I On July 7 of the present year I captured, in a wood near Newbury, a pair of the variety mystacea in copula. The male, the larger insect, was unusually indistinctly zoned. have submitted the specimens to Mr Verrall, who kindly tells me that the large male is certainly the variety mystacea, and he evidently thinks there is nothing remarkable about it. On the other hand, the female, which was unusually small, is more interesting, being somewhat an intermediate variety. As, Mr. Verrall informs me, Rondani has made about a score of intermediate species, this little capture of mine may turn out to be of interest, and it is comforting in a controversy of this kind to be able to add one fresh observation which may be of some use, if only in the way of confirmation. Now as to the statement, in which no ambiguity was intended, that the two varieties lay in the nests of the bees they respectively mimic. This was, as Mr. Bateson says, a very general impression, the impression of naturalists who knew these insects far better than I did, an impression which had already been expressed in the case at the College of Surgeons. If I was mistaken in adopting it, was it not well that I made the mistake, if by its means the general impression should be corrected, having in my book assumed a tangible shape? What man who cares for the advance of science more than for his own advancement would regret to have made a mistake under such circumstances? But I am not yet satisfied that the impression is nɔt substantially correct. I do not regard the dimorphism of V. bombylans as the unique phenomenon it appears to be in the opinion of Mr. Bateson. I fail to see any essential biological difference between it and the dimorphism of many Lepidopterous larvæ-a limorphism which extends into the pupal stage of most species of the genus Ephyra-or between it and the distinct types into which certain butterflies of the genus Kallima can be divided according to the colouring of the under sides of the wings, or certain moths of the genus Triphana according to that of the upper sides of the upper wings. But we know that in those cases which have been tested, while the majority of the offspring re semble the variety to which the parents belonged, a certain proportion follow the other variety, and when the parents belong to different varieties the offspring are more equally divided. It is therefore only to be expected, so far as our present knowledge goes, that both varieties should emerge from the same nest. The important thing to be ascertained, from the point of view of the theory of aggressive mimicry, is not the colour of the offspring which emerge, although this is of high interest on other accounts, but the colour of the parents which enter. It might be supposed that Mr. Bateson would have understood this, but it is perhaps too much to expect from a critic who is so aggressively uninterested. It would be interesting to know the grounds upon which Mr. Bateson considers the dimorphism of V. bombylans to be almost unique. At present he contents himself with assertions. If we were ever to return to the régime of authority and dogmatism in place of reason and experiment, Mr. Bateson's scientific position would be indeed assured. Years ago I was satisfied that the evidence for the state ment in my book was insufficient, and this, too, I had intended to modify when the opportunity occurred. In lecturing I have often alluded to the investigation as an interesting one, and only a fortnight ago suggested it to the members of the Natural History Society at Marlborough College. Two years ago I endeavoured to breed Volucella in the manner described by Mr. Bateson, I am sorry to say without success. I may therefore claim that the statement quoted by Mr. Bateson had produced. no paralysis of effort on my part either as regards my own work or that which I have been able to suggest to others. I may add that the upshot of this inquiry-even if it lead to the conclusion that both varieties lay indiscriminately in the nests of all the species they resemble-would not, in my opinion, remove the Volucelle from their place as examples of aggressive mimicry, but the working of the principle would be more complex. I do not, however, propose to render myself liable to further sneers about "ingenuity" by discussing it on the present occasion. Mr. Bateson's letter appropriately ends by putting into my mouth a defence I should never have advanced-a defence which was obviously inserted in order to impute discredit and then proceeding to the easy task of demolishing it. Let me therefore say that a mistake is to me a mistake, whether in a volume intended for the public or a paper presented to a scientific society. Indeed, I regret the former more than the latter. Unfortunately, too, mistakes are more liable to occur in the volume, because the ground is wider, and passes in some directions into less familiar regions. But I can honestly say that I have always done my best to avoid mistakes, and that I correct them as the opportunity arises, in fresh papers or in reprints of volumes. And I derive much comfort from Mr. Phelps' dictum, which I am sure appeals to every one who works, that "people who never make mistakes never make anything." EDWARD B. POULTON. Oxford, October 24. " P.S.-I wish to take this opportunity of correcting certain mistakes in my book ("Colours of Animals," Internat. Sci. Ser.), as it may be some time before the book can be reprinted, owing to the number of copies struck off. This will Pages 49, 50.-Dr. Hurst informs me that my abstract of Weismann's work on seasonal dimorphism is wrong. be carefully reconsidered in any reprint. Page 73.-I wish to withdraw the account of Phrynocephalus. Although the structures alluded to are probably alluring, there is not sufficient evidence as to the manner in which they are used. Page 85.-Professor Howes calls my attention to the description of the nerve-terminations in pigment cells. Page 94, et seq.-Sir J. Ross should be Captain James Ross. Page 105.-I ought to have added that Mr. Sharpe's conclusions are not accepted by Professor Newton. Pages 142-146.-Mr. Bateson has shown that the white cocoons of Saturnia and Eriogaster are not due to the white backgrounds employed, but to disturbance of the larvæ. It is still probable that the principle holds in Halias prasinana. Page 156. For the above reason I withdraw the argument about the cocoons of Rumia, although I believe that it still holds if H. prasinana be substituted. Chapters x., xi. should be read in connection with the experiments on Warning Colours since made by Mr. Beddard and published in his volume, "Animal Coloration." As Prof. Page 161.-The cockroach is not a good example. Weldon pointed out to me, there is no evidence that its unpleasant smell renders it unfit for food. The hive-bee would be a better instance. Page 193, line 7 from bottom.-Fibrous should be fulvous. Page 203, line 6 from bottom.-For suited for read bearing. Page 208, line 13 from top.-Divert should be direct. Page 224. I have since heard from Mr. Skertchly that he did not intend the argument which I quote at the bottom of the page to be taken seriously. Page 236.-Diadema bolina should be D. misippus, and it and the Danais it mimics occur in three varieties, not in I owe this to Col. Swinhoe; the error was copied from E. B. P. two. Trimen. The Geology of the Asiatic Loess. 'IN the spring and early summer of this year I had the opportunity, in company with Mr. S. B. J. Skertchly, of examining closely the loess deposits of Shantung, stretching from Chefoo to Tsinan, the provincial capital. The investigation convinced us both that the original loess of China must be regarded as a marine deposit. Subsequent to the time of Mr. Skertchly's leaving the province, on June 17, I was able to supplement these conclusions by the discovery of a band of limestone rocks bored by pholades and crustaceans up to a height of about 1100 feet, above which line no indications of late marine action were visible. The rocks in the locality near Tsinan-fu are carboniferous limestones interbedded with dioritic porphyries, and are still horizontal and unbroken for some thousands of square miles, having received their present contour in pre-loess ages. The dip for hundreds of square miles in this locality seldom exceeds from 2° to 8°. These facts we hope to make the subject of a joint memoir. The loess of China has, however, been traced almost continuously beyond the limits of the eighteen provinces to the foot of the Pamirs. West of the Pamirs loess occurs in the valley of the upper Oxus, probably in the Kizil Kum, and up to the Caspian, and its marine origin requires us to believe in the submergence within late geologic time of the greater part of Central Asia. Most geologists recoil at such a suggestion, and I am in a small minority in accepting the view that the present distribution of ocean and continent is of very recent date. I may, however, in condonation of heterodox views, refer to the position of the argument with regard to the alleged shifting of the terrestrial axis of rotation, which has within the last few years entered on a new phase. When some years ago I presented these views to the Council of the Geological Society of London they were scouted as utterly untenable. Since that time, while English astronomers have held the view that practically the axis of rotation has undergone, within the limits of observation, no change, American astronomers have come to the conclusion that a secular movement is actually in progress. My own geological observations in Europe, North America, and Asia have led me to infer that the North Pole has within recent geological time shifted, and that a shift is in all probability in progress at the present time along a line following approximately the direction of the 70th meridian of west longitude. This shift is not to be taken to involve a change in the direction in celestial space, but is rather a rolling of the earth over its axis, the latter remaining practically stationary. Dynamical causes sufficient to account for the change of position of the terrestrial poles, and in consequence of the parallels of latitude, seem to me to be at work. Prof. G. Darwin has calculated the probable change in the position of the pole due to an elevation of the bed of the Pacific Ocean, but no one has touched the converse effect of the change of the pole on the relative levels of the oceans and continents. In addition to the cause suggested in the possible elevation of large tracts of continental land, there are other influences at work tending in the same direction. The different distribution of the large masses of ice around the poles, which probably varies within somewhat large limits, and the slow disturbance of equilibrium re sulting from the growth of deltas and deep sea deposits, have frequently been adduced. More important still is perhaps the differential influence of tidal friction in retarding the rotation, the effect of which must be sensibly unequal in the two hemispheres north and south of the equator; another cause may be looked for in the action of aerial currents, the effect of which in the northern hemisphere as containing greater masses of elevated land must be greater. Another potential cause of shifting has never, that I am aware of, been formulated. Although at present of comparatively small influence, it must at various geological periods have been of great importance. It leads on to dynamic considerations of tidal energy beyond the compass of a letter to explain. The relative part played by the sun and moon, as deduced from gravitational formulæ, does not quite agree with the observed phenomena of our daily tides. It is believed by many that the ordinary lunar tide, affecting mainly the oceanic envelope, is complicated by the presence of a terrene tide largely influenced by the sun, and that the earth does to an appreciable extent yield twice in the twenty-four hours to the deforming force of solar gravitation. So long as this oscillation takes place at regularly recurrent intervals no energy is wasted. Should, however, a sudden snap occur, breaking the rhythm of the oscillation, some energy is evidently spent, and this can only be made up from the vis viva of rotation. Such snaps do occur occasionally; the regular oscillation is momentarily suspended, and the waters of the ocean rush in to restore the equilibrium. This is the wellknown "tidal" wave that so frequently occurs in connection with earthquakes. Such a snap on the equatorial line would simply retard the rotational period generally. North or south of this line, as the moments of rotation would be instantly unequal, the sphere would roll over its axis of rotation, and a shift in the position of the poles occur. The earth is not a perfectly rigid mass. Were it as rigid as steel, the interior within a depth of 200 miles would yet, under the pressure of gravitation, behave as a liquid; a shift in the pole would then be met either by a corresponding shift in the equatorial protuberance, or a change in the ocean level; or, more probably, by a compound action of both. In the latter case, to fulfil the conditions of equilibrium, the ocean surface in the neighbourhood of the new equator would rise, and if the shift were sufficiently great, would overflow the lowlands. If the equator, in the longitude of Central Asia, had at any former time passed north of its present position, and the rock masses of the Continent had not been elevated, a mid-Asian sea must have resulted. The undisturbed position of the carboniferous rocks, and the plain evidence that the surface sculpturing of the rocks was of pre-loess age, show that the process was unaccompanied by violent movements. The theory of the shift of the earth over its momentary axis accounts better than any other for the geological condition of polar lands, and I venture to state it again in brief, as on this occasion the initiative has come from the astronomers, not the geologists. THOS. W. KINGSMILL. Shanghai, China, August 20. Note on Mr. Kingsmill's paper. I think it will be difficult for Mr. Kingsmill to adduce evidence of geological changes large enough to produce any considerable shifting of the position of the principal axes of the earth, and accordingly I should feel sceptical as to a theory which postulates that such change has been sufficient to explain considerable changes of climate. With respect to a later part of the paper, I am entirely at variance with his views. As far as I know "the relative part played by the sun and moon in producing oceanic tides is in exact accordance with gravitational formulæ. extent. The existence of a terrene tide is a matter of speculation, but, as the earth cannot be perfectly rigid, it must exist to some The amplitude of the lunar terrene tide must certainly bear to that of the solar the same ratio that holds in the case of oceanic tides, and there is no reason, that I know of, for attributing a greater efficiency to solar action in the case of the deformation of the solid portion of the earth. I am quite unable to follow the argument by which the so-called "tidal" wave produced by earthquake shock is supposed to produce a retardation of the earth's rotation. October 21. G. H. DARWIN. THE rainfall here of October has been so remarkable that it seems worth while to place it on record in your columns. Rain fell on twenty-five days during the month, making a total fall of 10 32 inches. As the annual rainfall on an average of eleven years is 31 10 inches, it will be seen that very nearly one-third of this amount fell in one month. This is by far the highest amount I have recorded since I began to make records in January, 1878, the next highest month being August, 1879. On that occasion five inches fell in thirty hours on the 17th and 18th, and many bridges were carried away in Flintshire and Denbighshire, but the total fall for the month was only 7.89 inches. Dr. Nicol, of Llandudno (six miles from here), who has registered the rainfall since, and including 1861, informs me that it amounted last month to 8.56 inches there, this also being the highest month he has ever recorded. In September rain fell on twenty-three days, and though the total fall was only 3'77 inches, yet the constant rain, combined with an unusually low temperature (the mean maximum being only 566, and the highest shade temperature 67°4, against 64° 6 and 81°2 respectively in 1891), made it almost impossible to get in the harvest. ALFRED O. WALKER. Nant-y-Glyn, Colwyn Bay, November 5. On a Supposed New Species of Earthworm and on the Nomenclature of Earthworms. IN yesterday's NATURE I find that the Rev. Hilderic Friend has again given the name L. rubescens (Friend) to a supposed new species of earthworm. This worm appears to me to be identical with Enterion festivum (Savigny), described under the name Lumbricus festivus by Rosa. Though comparatively rare, it is by no means new, nor even new to Britain, though I know of no published record of its occurrence here. I met with two or three specimens among the worms supplied to me when I was working at the chapter on Lumbricus in "Marshall and Hurst," and identified them subsequently by the help of Rosa's table. At the time I took them for mere varieties, and put them into a bottle for future study. I believe the specimens are now in the possession of Dr. Benham, who has entirely overlooked the species in his "Attempt to Classify Earthworms" (Quart. Fourn. Micr. Sci. xxxi.). The specific name terrestris must also, it appears to me, be dropped. Linnæus did not define a species under that name, but applied it to what are now universally regarded as several distinct species. The species so called by Mr. Friend was, I believe, first defined by Savigny under the name Enterion herculeum. The diagnostic characters of the species are given by Rosa in his useful table of the species ("İ Lumbricidi dei Piemonte," p. 25), and he calls it Lumbricus herculeus, to which name the usual rules of nomenclature bind us. I would therefore suggest the following alterations in Mr. Friend's "Chart of the Genus Lumbricus" 1. For "Terrestris (Linn.)" read "herculeus (Sav.)" 2. For "Rubescens (Friend)" read "festivus (Sav.)" Owens College, October 28. C. HERBERT HURST. Ice Crystals. DURING the cutting of the formation for a railway I observed on Tuesday morning, the 18th inst., a peculiar series of ice crystals. The ground is composed of arenaceous clay largely mixed with sand and small gravel, and is of a very open nature, the surface being covered with moorland grass, rushes, and coarse ferns. These crystals were only found in a length of about nine feet, the ground on both sides of the patch being hard frozen. These crystals were acicular, and sprang from a base of very porous opaque ice, but every needle was entirely free and dis tinct throughout its height, and at first sight appeared to be bound together with two bands, one at one-third and the other at two-thirds of the height. A closer examination proved that crystals at these points, the ice being opaque, whilst the the band appearance was due to a slight enlargement of the needles were perfectly translucent. The average height of these crystals was about one inch, the grouped together in clusters of forty or fifty, forming an irregular needles having a diameter of about 4th part of an inch, and were square of about 1-inch on the side. Some of these crystals were growing vertically from the ground, others springing out horizontally from the side of the cutting, and were either straight, curved, or bent round forming a half circle. This morning the same form of crystals existed, but were much larger, being fully two inches long. On both occasions the air was calm and clear, the min. ther. reading 30° on the 18th, and 24° to-day. Lesmahagow, October 25. C. M. IRVINE. Lunar Craters. THE letter and illustration offering a suggestion as to the formation of lunar craters remind me of an experiment I once saw during a chemical lecture, bringing out the same point very clearly. A shallow dish containing a layer of damp sand, ', was flooded with 1-inch coating of Paris plaister, of the consistence of cream, and the dish set to dry over a Bunsen flame. As the plaister set, the surface was pitted with crater-like holes, formed by the escape of steam from the sand at the bottom of the dish, giving a perfect representation of a lunar surface. As some of your readers might care to try this experiment, I take the liberty of sending you this "recollection." M. H. MAW. Walk House, Barrow-on-Humber, Hull, Nov. 7. A Fork-tailed Petrel. THE Occurrence of a Fork-tailed Petrel as far inland as Macclesfield may perhaps interest some of the readers of NATURE. It was picked up by a man on the 11th ult., two days after the stranding of the Sirene in a gale at Blackpool, and being unacquainted with the species he sent it to me as a curiosity. I identified it as a Fork-tailed Petrel, and Mr. J. H. Salter, of Aberystwyth College, has kindly confirmed this decision. Some of the feathers on the forehead are tipped with white. Does this indicate a young bird, as I can find no mention of it in any of the plumage descriptions that I have seen? NEWMAN NEAVE. Rainow, near Macclesfield, November 5. THE ORIGIN OF THE YEAR. III. IN the previous articles I have endeavoured to show that the Egyptians had the Sirius year and the vague year so related to each other that the successive coincidences of the 1st Thoth in both years took place after intervals of 1460 Sirian years. With a real year, the length of which would be brought home to them by the regular recurrence of the solstices and Nile flood (to say nothing of the equinoxes) and the year of 360 days which they would soon find to be quite artificial and unreal; they would be much more likely to refer the dates in the artificial year to the real one, than to take the opposite course, and, as I have shown, the artificial dates would sweep backwards through the real ones. Such a method of reckoning, however, would be useless for calendar purposes, as they not only wanted to define the days of the year but the years themselves, and I pointed out that something more was necessary, and that an easy way of defining years would be to conceive a great year, or annus magnus, consisting of 1460 years, each "day" of which would represent four years in actual time; and further to consider every event, the year of which had to be chronicled in relation to others to take place on the day of the heliacal rising of Sirius or the nearly coincident Nile flood, which, was employed to mark the first year of each series of four. Now as a matter of fact it is known (I have the high authority of Dr. Krall for the statement) that each kieg was supposed to begin his reign on the 1st Thoth (or 1st Pachons) of the particular year in which that event took place, and the fact that this was so supports the suggestion we are considering. During the reign its length and the smaller events might be recorded in vague years and days so long as the date of its commencement had been referred to a cycle. We have next to consider more especially the vague year. One argument which has been used to show that a vague year was not in use during the time of the Ramessids has been derived from some inscriptions at Silsilis which refer to the dates on which sacred offerings were presented there to the Nile-god. As the dates 15th of Thoth and 15th of Epiphi are the same in all three inscriptions, although they cover the period from Ramses II. to Ramses III.-120 years-it has been argued by Brugsch that a fixed year is in question. Brugsch points out that the two dates are separated by 65 days; that this is the exact interval between the Coptic festivals of the commencement of the flow and the marriage of the Nile-the time of highest water; and FIG. 5.-The distribution of the 1st of Thoth (representing the rising of Sirius) among the Egyptian months in the 1460 year Sothic cycle. as we shall see, occurred, at different periods of Egyptian history, on the 1st Thoth and 1st Pachons. A diagram, which may here be repeated, was given to show how such a system would work. From any coincidence of 1st Thoth (or 1st Pachons) in both the Sirian and the vague year, since the vague year is the shorter, the 1st Thoth (to deal only with Thoth) of the vague year would recede; so that in such a cycle it would fall first among the Epacts, then in Mesori, and so on through the months, till the next coincidence was reached. The diagram will show how readily the cycle year can be determined for any vague year. If for instance the Ist Thoth in the vague year falls on 1 Tybi of the cycle, we see that 980 years must have elapsed since the beginning of the cycle, and so on. Here, then, we have a true calendar system; if the Egyptians had not this, what had they? Such a calendar system as this it will be seen, however, is good only for groups of four years. Thus during the first four years of a cycle the 1st Thoth vague would happen on 1st Thoth of the cycle, during the next four years on the 5th Epact, and so on. Now a system which went no further than this would be a very coarse one. We find, however, that special precautions were taken to define which year of the four was in question. Brugsch 2 shows that a special sign 1 Continued from vol. xlvi. p. 107. 2. Matériaux pour servir à la reconstruction du calendrier," p. 29. that, therefore, in all probability these are the two natural phenomena to commemorate which the offerings on the dates in question were made. But Brugsch does not give the whole of the inscription. A part of it, translated by De Rougé,1 runs thus: "I (the king) know what is said in the depot of the writings which are in the House of the Books. The Nile emerges from its fountains to give the fullness of life necessaries to the gods," &c. De Rougé justly remarks: "Le langage singulier que tient le Pharaon dédicateur pourrait même faire soupçonner qu'il ne s'agit pas de la venue effective de l'ear sainte du Nil à l'une des deux dates précitées." Krall (loc. cit. p. 51) adds the following interesting remarks:-" "Consider, now, what these 'Scriptures of the House of Life' were like. In a catalogue of books from the temple of Edfu, we find, besides a series of purely religious writings, The knowledge of the periodical recurrence of the double stars (sun and moon. and the 'Law of the periodical recurrence of the stars.' "... The knowledge embodied in these writings dated from the oldest times of the Egyptian empire, in which the priests placed, rightly or wrongly, the origin of al their sacred rolls" (cf. Manetho's History," p. 130). Now to investigate this question we have to approach some considerations which at first sight may seem to be "Aeg. Zeit," 1886, p. 5, quoted by Krall. foreign to our subject. I shall be able to show, however, that this is not so. Imprimis we must remember that it is a question of Silsilis, where we know both from tradition and geological evidence, in ancient times the first cataract was encountered. The phrase "The Nile emerges from its fountains" would be much more applicable to Silsilis, the seat of a cataract than as it is at present. We do not know when the river made its way through this impediment, but we do know that after it took place and the Nile stream was cleared as far as the cataract that still remains at Elephantine, a Nilometer was erected there, and that during the whole of later Egyptian history at all events the time of the rise of the river has been carefully recorded both there and at Rhoda. From this it is fair to infer that in those more ancient times the same thing took place at Silsilis; if this were so the reason of the record of the coming of the inundation at Silsilis is not far to seek, and hence the suggestion lies on the surface that the records in question may state the date of the arrival in relation to Memphis time. So far in my inquiries I have not been able to find a complete discussion of the influence upon local calendars, in different parts of the Nile valley, of the variations of the phenomena upon which the Egyptians depended for the marking of New Year's day. If the solstice had been taken alone, the date of it would have been the same for all parts of the valley; but certainly the solstice was not taken alone, and for the obvious reason that they wanted something to warn them of the Nile rise, and in the lower reaches of the river the rise precedes the solstice. Nor was the heliacal rising of Sirius taken alone. As we have seen, according to Biot the heliacal rising of Sirius at the solstice took place on July 20 (Julian) in the year 3285 B.C.; and according to Oppolzer, it took place on July 18 (Julian) in the year 3000 + B.C. But this is too general a statement, and it must be modified here. There was a difference of 7 days in the date of the heliacal rising, according to the latitude, from southern Elephantine and Philæ, where the heliacal rising at the solstice was noted first, to northern Bubastis. There was a difference of four days between Memphis and Thebes, so that the connection between the heliacal rising and the solstice depended simply upon the latitude of the place. The further south, the earlier the coincidence occurred. Here we have an astronomical reason for the variation in the date of New Year's day. But it was chiefly a question of the arrival of the Nile flood, and the date of the commencement of the Nile flood was by no means common to all parts of Egypt! I cannot find any statement of the dates of the arrival of any one Nile flood at places between Elephantine and Cairo, Dr. Wallis Budge' states: "The indications of the rise of the river may be seen at the cataracts as early as the end of May." Now if we take the 1st cataract to be here meant, and deal with May 31; since the average day of arrival of the inundation at Cairo is 3 days after the solstice-that is June 20 (Greg.)-we have 24 days for the flood-travel for the 600 miles between Elephantine and Cairo, four-fifths of a month elapsing between the times at which the Green Nile colours the pool at Syene below the Cataracts, and the river at Memphis; so that the further south, the Earlier the flood was noted. This gives us about a mile an hour. This certainly seems too slow. But if we assume 16 days, this would give us about 5 days between Silsilis and Cairo, and 12 days between Thebes and Cairo, taking Cairo to represent the ancient Memphis. Now this represented a difference in the new ear's days of different places, compared to which our "The Nile," p. 46 modern differences of local time sink into insignificance, for they only touch hours of the day; and the reason that I have referred to them here is to point out that if the assumption made is anything like accurate, if, for instance, in Pepi's time a Nile rise were observed at Silsilis, there might easily be a difference of 15 days between the rise of the Nile at Silsilis and the Memphic 1st of Thoth. If both at Silsilis and Memphis the Nile rise marked 1st Thoth, the day of the rise at Memphis would correspond to 15th Thoth at Silsilis, so that a king reaching Silsilis with Memphis local time, would be struck with this difference, and anxious to record it, may not this then have been the important datum recorded in the sacred books? If so, it would not touch the question of the fixed or vague year at all. Let it, then, be for the present conceded that there was a vague year, and that at least some of the inscriptions which suggest the use of only a fixed year in these early times may be explained in another way. I do not say the above explanation is the correct one, for the assumption of 16 days may be wrong, even if difference in the dates of the heliacal rising at the two places be taken into account. The dates we have found-trying to take the very simplest way of writing a calendar in pre-temple times, and using the calendar inscriptions in the most natural way-are for the coincidence of the heliacal rising of Sirius at, or near, the solstice |