Sept. 28, ItS?.] 



♦ KNOWLEDGE ♦ 



197 



bear, in wliich was one molar tooth. This at once esta- 

 blished M'Enery's accuracy, left no doubt that J/ac/(«2Vo(7»s 

 latidens was a member of the cave earth fauna — whatever 

 the zoological aflinitifs might say to the contrary — and 

 proved that man and Machuirodus were contemporaries in 

 Devonshire. 



When their exploration began, and for some time after- 

 wards, the committee had no reason to suspect that the 

 cavern contained anything older than cave earth. At the 

 end of the first five months, however, facts pointing ap- 

 parently to earlier deposits began to present themselves, 

 and when, after the expiration of three years, a vertical 

 section was cut, there was shown in clear, undisturbed 

 succession, not only the cave earth with the granular 

 stalagmite lying on it, but under, and apparently support- 

 ing the cave earth, another thicker and continuous sheet 

 of stalagmite called crystalline, and below this, again, 

 an older detrital accumulation known as the Breccia, 

 made up of materials utterly unlike those of cave earth. 

 The Breccia was just as rich as the cave earth in osseous 

 remains, but the lists of species represented by the two 

 deposits were very different. The remains of the hy»na 

 prevailed numerically very far above those of any other 

 mammal in the cave earth, his presence being attested by 

 his teeth-marks on a vast number of bones, by lower jaws — 

 including those of his own kith and kin — of which he had 

 eaten ofithe lower borders as well as the condyles, by long 

 bones broken obliquely just as hya-nas of the present day 

 break them, and by surprising quantities of his coprolites. 

 In the Breccia, however, there was not a single indication 

 of his presence, the crowd of bones and teeth belonging 

 almost entirely to bears. No trace of man was found in 

 the Breccia until March, 1870, when a flint fiake was met 

 with in the third-foot level, which was believed to be not 

 only a tool, but to bear evidence of having been used as 

 such. Two massive flint implements were discovered in 

 the same deposit in May, 1872. 



At various times other tools were found, until at the 

 close of the exploration the Breccia had yielded upwards 

 seventy implements of flint and chert. All the stone tools, 

 both of cave earth and Breccia, were Palaeolithic, and were 

 found inosculating with the remains of extinct mammals, 

 but a cursory inspection showed them to belong to two 

 distinct categories. Those found in the Breccia, the more 

 ancient series, were formed by chipping a flint nodule or 

 pebble into a tool, while those from the cave earth were 

 formed by first detaching a suitable flake from the nodule, 

 or pebble, and then trimming the flake — not the nodule — 

 into a tool. 



The fact, however, most significant of time and physical 

 change was the presence of the hyrena in the cave earth 

 or less ancient, but not in the Breccia or more ancient 

 of the two deposits. This fact rendered it almost im- 

 possible to avoid the conclusion that the liyana was not 

 an occupant of Britain during the earlier period. The 

 acceptance of such a belief, however, would necessitate 

 the adoption of the view that man was resident in 

 Britain long before the hya'na, and also that it was 

 possible for the hyiena to reach Britain some time 

 between the deposition of the Breccia and the deposition 

 of the cave eartli. In other words, that Britain was part 

 of the continent during this interval. 



In support of this argument, it is to be remembered that 

 Sir Charles Lyell recognised the following geographical 

 changes within the British area between the newer pliocene 

 and historical times — firstly, a pre-glacial continental 

 period, towards the close of which the Forest of Cromer 

 flourished and the climate was somewhat milder than at 

 present ; secondly, a period of submergence, when the land 



north of the Thames and Bristol Channel and that of 

 Ireland was reduced to an archipelago. This was part 

 of the glacial age, when icebergs flrated in our waters. 

 Thirdly, a secoiid continental period, when there were 

 glaciers in the hiol.er mountains of Scotland and Wales. 

 Fourthly, the breaking up of the land through submergence 

 and a gradual change of temperature, resulting in the pre- 

 sent geographical and climatal conditions. 



The fact that neither in the Kent's Cavern Breccia, nor 

 in the Forest of Cromer were any remains of hycena 

 found, and that the list of mammalian remains found in 

 the one does not clash with those found in the other, 

 renders legitimate the inferences that the hyaena did not 

 reach Britain until its last continental period, and that 

 the men who made the Pakeolithio nodule tools found in 

 the oldest-known deposit in Kent's Cavern arrived either 

 during the previous great submergence, or, what is more 

 probable, unless they were navigators, during the first con- 

 tinental period. There was little doubt, therefore, but 

 that the earliest Devonians were either of glacial or 

 pre-glacial age. Of course, the discovery of remains of 

 hya'na in the forest bed of Cromer, or any other con- 

 temporary deposit, would be fatal to the argument, but 

 it would leave intact all other evidence in support of the 

 doctrine of British glacial or pre-glacial man. 



THE SUN'S DISTANCE.* 



Br Professor E. S. Ball, LL.D., 



As1 ronomer-Royal for Ireland. 



THE problem which is to engage our attention has 

 been justly regarded as one of exceptional interest 

 and importance. It seems not unlikely that in early 

 ages the distance of the sun was one of the very first 

 astronomical problems which ever attracted speculation. 

 In modern times, as the problem has gradually approached 

 solution, the interest attached to it has gradually increased 

 until it has culminated in the last few months by the 

 occurrence of the transit of Venus. 



The importance of this problem arises from the fact that 

 the distance of the sun is the base line in terms of which 

 almost every other linear magnitude in astronomy is to be 

 expressed. An accurate measurement of this base will 

 infuse accuracy into all the other astronomical quantities 

 which spring from it. When we have learnt the distance 

 of the sun we can measure the bulk of the sun and his 

 diameter, we can measure the great planet Jupiter or the 

 rings of Saturn, and the scale of the whole solar system 

 becomes known to us. Again, when we attack the loftiest 

 problem in practical astronomy, and seek to stretch a 

 sounding line over the vast abyss which divides our system 

 from the stars, it is the distance of the sun wliich we must 

 use as our measuring rod. Ko pains should be spared to 

 give to so fundamental a unit all the precision of which it 

 is capable. 



Let us define accurately the magnitude to be measured. 

 The actual distance from the earth to the sun is not con- 

 stant. In these autumnal months the distance is rajiidly 

 decreasing. We are at this moment drawing nearer and 

 nearer to the sun at the rate of a thousand miles an hour. 

 Next Christmas we shall be about a million and-a half 

 miles closer to the sun than we are to-night At the com- 

 mencement of the new year we shall begin to recede. 

 Next mid.^ummtr will find us as far from the sun as 

 possible ; then we shall draw in again, arrive next autumn 



* A discourse delivered nt the second general meeting of the 

 British Association at Sonthport. 



