• KNOWLEDGE 



27 



the sun, even if their astrologers understood this they could find no 

 recorded law of recurrence of solar eclipses within that period by 

 which to predict them. Because, though they recur in fixed order 

 within the cycle, they are not visible at the same places on their 

 repetition, as where first observed, whereas all lunar ones are, of 

 course, to be seen at all parts of the earth having the moon above 

 the horizon. That the Assyrians ever arrived at the truth is very 

 questionable, although Professor Sayce seems to think that the 

 problem of calculating solar eclipses by tracing the shadow as pro- 

 jected on a sphere had presented itself to them ; for; when we first 

 hear of a correct prediction of a solar eclipse, it is by a man who 

 gained his wisdom not in the astrological observatories of Assjria, 

 but in the sacerdotal colleges of Egypt. 



The quotations already given (which might easily be multiplied) 

 are ample to prove that whilst the Babylonians were far from 

 perfect in their calculation of solar eclipses, j-et they so thoroughly 

 understood those of the moon, and were generally so far advanced 

 in astronomy, that they knew much better than to predict an eclipse 

 of the sun on the 20th of a lunar month. In fact it is evident that 

 their months must have been so arranged that these phenomena 

 could take place upon any one of the days. For instance, in what 

 are termed " Portent Tablets," translated by Prof. Sayce, are 

 numei'ous lists of omens arising from lunar eclipses on such 

 days as the 13th, 14tli, 15th, 16th, 20th, 2l9t, Ac. It does not 

 follow from other days not being mentioned that eclipses 

 were not anticipated on them, because their omission may be 

 owing to parts of the portent tablets being wanting ; or, their 

 occun-ence upon these other days, not being associated with any 

 omen, are unnoticed. Mr. Sayce tells us that records of eclipses 

 for every day of the year were kept. In the " Cuneiform Inscrip- 

 tions of Western Asia," vol. III., p. 56, published by the British 

 Museum, we have lists of events to be apprehended if an eclipse 

 happened on any day of the month Tammuz up to the 15th. Else- 

 where wo read — " In Tammuz, from the 1st to the 30th, if an 

 eclipse happen the altars are destroyed," &c. ; and, again, " In the 

 month Sivan, from the 1st to the 30th, an eclipse failed, the crops 

 of the land are not good ; " and, as a final instance, this curious 

 sentence may be given relating to an unexpected eclipse — "If, in 

 the month Tammuz, an eclipse happens, which has not been calcu- 

 lated, the heart is established." That the disappointment in the 

 one instance, and the unexpected good fortune in the last, refer to 

 miscalculated solar events is evident from what has been said 

 above. 



It only remains to bo ascertained what was the length of the 

 Babylonian months, and to this there is now no doubt that tho 

 correct answer is, as stated by Prof. Sayce, that they were months 

 of thirty days,* as were those of the time of the flood (Gen.vii., 11 ; 

 viii., 3, 4) ; thus their year would bo one of 360 days, corresponding 

 with the Egyptian vague year. That this is the'true state of the 

 case is evident, because we know that every six years an extra 

 month was intercalated, the Ve Adar, in order to make the year 

 coincide with the solar year. The year of 360 days being five 

 short, in six years tho correction was made, because then the 

 error amounted to a month. This, however, was not sufficient to 

 entirely rectify the difference, being about thirty-five hours in error, 

 and in 124 ye:irs the deficiency would amount to a whole month of 

 thirty days, and so we accordingly find another intercalary month 

 mentioned in the inscription, the " second Elnl." Xow, whilst a 

 :iC0 day year is about five days less than the solar, it is nearly six 

 days more than a lunar year ; thus in about five years tho days of 

 the month wonld advance through a whole lunar month, just as in 

 six years they would retrograde a whole mouth as compared w^ith 

 the solar year. The effect of this would be that in a period of five 

 years eclipses could and would take place on any day of the month. 

 A curions confirmation of this is to be found in tho report tablets 

 consisting of records of careful observations for tho new moon on 

 tho Ist and 30th days of the month ; these, doubtless, being ac- 

 counts of observations made at tho end of tho five year periods to 

 see if the error of six days annually had rectified itself, and tho 

 new moon once more coincided with tho Ist of the month. The 

 Eg)-ptians, it is well-kno^vn, rectified tho (360 day) vague year, 

 with tho solar, by intercalating five days annually ; but thero is 

 reason to think this practice did not exist in the earliest times, 

 because each of these five days is sacred to (one of tho great gods, 

 which seems as if it were a plan of the priests introduced with tho 

 innovation in order to render it permanent. 



It is not supposed that these explanations clear up all tho diffi- 



• M. Lenormant ("Ancient History," 451) argues that tho 

 months, like those of tho Jews after tho time of Moses, were alter- 

 nately of twenty-nine and thirty days ; practically lunar ones, 

 but two of those to which ho assigns only 29 days, lynr and 

 Marcheavan are mentioned in inscriptions, translated by the late 

 Geo. Smith as months of thirty days. 



culties of tho Babylonian calendars, because there is reason to 

 believe that sometimes one of the intercalary months was a second 

 Marchesvan,'and Mr. Pinches finds eridence of there occasionally, in 

 some sense, being intercalary days ; but they are offered in the hope 

 that they may be a preliminary step towards arriving at tho truth. 

 Joseph Offobd. 



w 



SIEMENS OX SOLAR ENERGY. 



have received from " X, University Club, Dublin," a letter 

 respecting Dr. Siemens' scheme of the solar energy. The 

 letter is marked " private," but how an anonymous writer can 

 claim that his letter should be regarded as a private communication, 

 we fail to see. We therefore disregard the injunction. 



Beginning with the remark that our argument from the light of 

 the stars seems to dispose of Dr. Siemens' theory, " X " presents 

 Dr. Siemens' dynamical argument as akin to the following state- 

 ment : — 



" If a globe (representing the sun and its rotating atmosphere) 

 be made to rotate in the still air of a room, there will bo produced 

 an outflow of air all round the equator from which will result 

 inflow at both poles." 



And he adds, " Surely this proposition needs only to be stated to 

 be accepted." 



We accept all except the words in parentheses. The globe 

 hanging in the still air of a room, and exerting scarcely any appre- 

 ciable attraction on the air, does not and cannot represent the sun 

 rotating in tho atmosphere of space. The rotating sun cannot 

 generate any such tangential velocity as could lead to equatorial 

 outflow, — the rotating globe in a room can. 



The fundamental error of Dr. Siemens' position is tho assump- 

 tion — in which X follows hira — that gaseous matter outside the 

 sun's rotating atmosphere, will yield to the influence of any centri- 

 fugal tendenc3' which may be communicated to it, but is not under 

 the influence of solar attraction. 



The same fallacy underlies, I suspect, tho following assertioD(I 

 suspect onlij, because X does not tell us what he really means) : — 



" You have only to reconsider the statement about ' the pressures 

 wliich could exist opposite the polar regions [of the sun], and the 

 consequent resistance to ivfiou;' to see that the underlined words 

 must not stand." 



Of course, if, as X and (manifestly) Dr. Siemens suppose, the inter- 

 planetary atmosphere were free from solar attraction, and the sun 

 were like a ball spinning in the still and apparently uniform air of 

 a room, the underlined words could not stand. As matters are 

 otherwise, they can, and do. If X will examine the conditions as 

 they would actually exist (the interplanetary atmosphere being 

 assumed), ho will see that, whether the pressures op|x>sito the polar 

 regions are at any moment in excess or in defect of those which 

 would result in equilibrium, there can never bo other than oscillatory 

 movements in the interplanetary atmosphere. There will always 

 be resistance to inflow— that is, to tho ^constant inflow, which the 

 theory requires : there mil equally be resistance to [constant] 

 outflow. RicHABD A. Pboctor. 



WiNNMSG Wagers. — It will hardly be believed, but our paper 

 thus named has actually been understood by some of our readers 

 as a guide to successful wagering ! It is as painful to havo to in- 

 terpret sarcasm as to have to explain a joke ; but for the benefit of 

 those (very few we trust) who havo misunderstood us, wo explain 

 that the whole aim and purport of our paper was to indicate tho 

 rascality of tho only kind of wagering which is ever systematically 

 successful, — tho system pursued by the bookmaking fraternity. Wo 

 might as reasonably bo supposed to inculcate the true principles of 

 pocket-picking, if wo warned readers against the tricks of street 

 thieves, as to advocate the tnio principles of ^vagering, when wo 

 show how bookmakers swindle verdant bettors. 



Killing ENToMoLor,ic.\L SrKCiJiKN.s.— In tho column on "Butter- 

 flies and Moths," p. 606 of Knowledgk, several methods of killing 

 the animals arc described. Some twenty years ago, I tried many 

 experiments with this intent, and finally discovered that the bisul- 

 phide of carbon is effectual. It is a vorj" volatile liquid, its vapour 

 very dense. The insects, either before or after pinning out, may 

 be placed in a wide-necked bottle or a tin box in which is a piece 

 of wool that has been slightly wettoil with tho bisulphide. U 

 should remain thero a few minutes, as a shorter time only produce's 

 temporary insensibility. I described this method in the ninth 

 volume of A'aturc, and it has since been extensively used in Franco 

 for tho destruction of phylloxera. — W. Mattiki: Wii.liam.i. 



Poim'a KxTiiCT li * rartmin cor* for Kheumalnm ud Ooat. 

 Pond'i BztrMt ii » c«rt»iii cure for llmnorrhoidi. 

 PoDd'l Rilnct in ■ c<<rt»iii corn for Mmrmlttio p<uiu. 

 Pond's Extract will heal Bum<i luid Woundti. 



frainn Mid Brui»c«. 

 Chamitti. 0«t th* (Miiiia*. 



