November 28, 1912] 



NATURE 



361 



then becomes, it seems to me, not to decide between 

 two theories of X-rays, but to find, as I have said 

 elsewhere, one theory which possesses the capacities 

 of both. ' W. H. Bragg. 



Worked Flints obtained from " the 25-foot Raised 

 Beach " near Holywood, co. Down. 



The 25-foot raised beaeli is well marked all round 

 the northern and eastern coast of Ireland, and is 

 also recognisable on the opposite coast of England 

 and in the Isle of Man. This post-Tertiary beach is 

 contemporaneous with the Upper Estuarine Clays of 

 the Belfast sections,' and is certainly not later than 

 early Neolithic. At different times worlced flints have 

 been obtained from this beach, notably from Larne, 

 CO. Antrim, and have been discussed, but no clue to 

 their date or dates has been found. I have lately had 

 the opportunity of carefully examining the section 



^ 



3. ^t,sf<^ 3f^^ r^^*^^ «^SA^^ -^'-f' 



(Fig. I and 2) near Holywood, co. Down. From a 

 350-ft. exposure 683 worked flints were obtained. 



Description. Per cent. Notes. 



Chipped on non-bulbous 

 29"6 face only. 4LeMoustier 



type. 

 21 "6 All with tang. Worked on 

 non-bulbous face only, 

 zopercent. withshoulder 

 (Les Eyzies). 

 20'o 85 per cent, showing cen- 

 tral ridge. 



Punches, adzes, chisels, celts, cores, borers, microliths, about 

 4 per cent, each class. 



No polished specimen was obtained, and all were 

 ot Palaolithic form, generally chipped on one face 

 only. From the surface of the Boulder Clay specimens 

 were obtained which had been subject to rolling before 

 settlement of the land took place. Eight specimens 



1 Praeger, Proc. Roy. Irish Acad., vol. iv., 1897. 



NO. 2248, VOL. 90] 



showed re-chipping. Three prickers made from the 

 ulna of deer were found. I submit that, considering 

 the evidence of late Paljeolithic work in Scotland in a 

 similar horizon, the geological evidence, and the form 

 and working of the flints found in this beach, they 

 should be described as Mesolithic. 



Henrv Ho.me. 

 Bellevue, Holywood, co. Down. 



Note on the Upper Partlals of a Tuning-fork. 



It is well known that a smoked dropping plate can 

 be used to find the pitch of a fork if the value of g 

 is linown, and the method is described in most of the 

 text-books on sound. But so far as tlie v.'riter is 

 aware no attention has been directed to the fact that 

 the existence. of some of the upper partials can also be 

 demonstrated with it and their frequency obtained. 

 The metliod is simpler and more convincing to a 

 student than the method of using resonators. 



As an example the traces of the fundamental and 

 the first two upper partials are shown in the diagram, 

 which is a copy of the photograph of the traces on the 

 dropping plate. The fundamental frequency of the 

 fork used was 29^5, and the frequency of the first two 

 upper partials should be (see Barton, ''Text-book of 

 Sound," §211) 185 and 518, while the numbers ob- 

 tained from a single observation were 184 and 512 

 respectively. No attempt was made to obtain other 

 partials, but doubtless the next two could have been 

 obtained. F. H. Parker. 



Woolwich Polytechnic, November 9. 



The March of Science. 



In a school text-book, published in 1846 at Phil- 

 adelphia, from which I was instructed in 1848 — it 

 was a geography, but contained five lessons in 

 astronomy — is the following information about the 

 sun : — 



" In former times, it was supposed that the sun 

 was a great ball of fire. Many learned men, however, 

 are of opinion that it is a world like our own, con- 

 taining continents, oceans, mountains, and plains. 



"It is supposed that the rays of light which illu 

 mine the Solar System, proceed from an atmosphere, 

 or air, of a peculiar nature, that surrounds the sun. 

 The rays of the sun are called solar rays. 



"When mingled with the atmosphere on the surface 

 of the globe, it is thought that these rays produce 

 the warmth and animation which render the earth 

 habitable. 



" This appears probable, from the fact that the sum- 

 mits of high mountains are always covered with ice 

 and snow, while at their base, and in the valleys, the 

 heat is oppressive. If heat proceeded from the sun, 

 as from a body of fire, the higher we ascend from 

 the surface of the earth, the greater the heat would 

 become." 



As I was only seven years old at the time I studied 

 the book, the information did me no harm. 



E. S. 



Brooliline, Mass., U.S., November 9. 



