FOR GENERAL READERS. 



Vol. II. 



FRIDAY, AUGUST 24th, i? 



No. 8. 



CONTENTS. 



Scientific Table Talk 



The Naturalist at the Sea-Side : 



VI. — Petrified Seaweeds 

 Sun Dials, and How to Make Them.- 



III. (illus.) ... _ ... 



The Shipman Automatic Engine 



(illus.) 



Extinct British Butterflies. —III. 



General Notes 



Portable Magic Lantern (illus.) 



Notes for Young Collectors 



Natural History : 



The Senses of Insects (illus.) — I. 



PAGE 





PAGE 



I69 



The Botany of Bristol— I 



Reviews : 



181 



170 



Transactions of the Cumberland 

 and Westmoreland Association 





171 



for the Advancement of Litera- 







ture and Science 



182 



172 



Management of Accumulators ... 



iS.S 



«73 



My Microscope 



18.3 



•75 



Roman Bath. — I 



18? 



177 



British Medical Association ... 



i«S 



178 



Abstracts of Papers, Lectures, etc. : 







Junior Engineering Society 



187 



179 



The Cambrian Archaeological 







Association 



187 



Wiltshire Archaeological Society 



Correspondence : 



Formation of Ice— Petals of the 

 White Jasmine — Tennyson as an 

 Observer — Peculiar Water— Dye 

 Colours from Plants and Shrubs- 

 Cobras — Sparrow Hawk and 

 Kestrel — Fertilisation of Flowers 



Recent Inventions 



Sales and Exchanges ... 



Selected Books... 



Notices 



Meteorological Returns 



PAGE 

 188 



191 

 192 

 192 

 192 

 192 



SCIENTIFIC TABLE TALK. 



By W. Mattieu Williams, F.R.A.S., F.C.S. 

 The recently published report of Dr. Hans Reusch, of 

 the Norwegian Meteorological Institute, on the earth- 

 quakes that occur annually in Norway, appears to have 

 surprised some of us who reside farther to the south, but 

 a little reflection on the subject must show that Norway 

 is one of those countries in which a priori considerations 

 should lead us to expect a frequent occurrence of earth- 

 quakes. 



It is well known that the regions surrounding our exist- 

 ing and active volcanic centres are specially liable to earth- 

 quakes. A glance at a map will show that the coast of 

 Norway is just that part of the continent of Europe which 

 is the nearest to the most active European volcanic 

 region, viz., that of Iceland. The places specially named 

 in Dr. Reusch's report are those nearest to Iceland. 



The islands of Vaero and Rost, where " doors and 

 windows clattered and the slates of roofs were pitched 

 off," are the outermost and southernmost of the Lofoddens 

 those which stretch out the nearest towards Iceland. Bodo, 

 also mentioned, is on the coast just opposite to them. 

 Yttero, another place specially named, is an island stand- 

 ing off the coast just opposite the southernmost extremity 

 of Iceland, as Bodo, Rost, and Vaero are opposite its 

 northernmost extension, which just touches the Arctic 

 circle. (See page 152 of this volume.) At and between 

 these the maximum of shaking occurs. 



It is further to be noted that a very remarkable 

 physiographical feature of Scandinavia attains its maxi- 

 mum thereabouts. I refer to the terraces of till and 

 alluvium which run up all the valleys opening on the 

 west coast, whether those valleys be sea-paved and thus 

 constitute the fjords, or whether they form the troughs of 

 rivers or torrents in which all the fjords terminate. 



Before knowing anything about the earthquakes of this 

 region (1877) I wrote as follows of the valley which opens 

 out in a fjord nearly opposite to Yttero : " The valley of 

 the Nid, like all the greater valleys of this region, is a 

 gigantic staircase of two, three, or more, up to a dozen 

 steps, the steps varying from 8 ft. or 10 ft. to about 

 100 ft. high, and with all breadths, from half a yard to a 



mile or two. The top of each of these steps, i.e., of the 

 terraces in this part of this valley, are beautifully flat — 

 ready-made croquet-lawns if merely rolled and mowed." 



The upper terrace in all these valleys is about 600 feet 

 above present sea-level, but is less in the southern valleys. 

 About half-way between Yttero (" Hitteren " on many 

 maps) and the arctic circle is a very curious island, Tor- 

 ghatten, which is perforated from east to west with a 

 tunnel 530 feet long, 66 feet high from floor to roof at its 

 eastern entrance, and 250 feet high at its western or 

 oceanward entrance. The roof of the tunnel varies from 

 650 feet above sea-level on its west side to 530 on the 

 east. It thus corresponds very closely to that of the 600 

 feet ot the upper terraces of the valleys. 



Many curious traditions concerning the origin of this 

 tunnel are extant, in spite of which I ventured to suggest 

 the following, in the first edition of " Through Norway 

 with a Knapsack," published in 1859: "When the 

 whole of the northern coast of Scandinavia was .some 

 600 feet below its present level Torghatten was of course 

 similarly lower, and the floor of this tunnel was washed 

 by the low tide waves. The waves of previous centuries 

 had, aided by other agencies, such as frost and the gravi- 

 tation of overhanging masses, formed this tunnel as an 

 ordinary sea cavern, and the great upheaval had raised it 

 to its present place." 



Since the above was written the tunnel has been care- 

 fully examined by a Geological Commission of the Uni- 

 versity of Christiania, and their report confirms my 

 general explanation, but shows that " frost and the 

 gravitation of overhanging masses " have done more than 

 I at first anticipated. The amount of debris on the floor 

 is very great, and fully accounts for the additional 50 ft. 

 ot height at the end exposed to the full sweep of the 

 ocean. The original solid rock floor is correspondingly 

 lower than the present rubble floor, indicating, if the 

 general explanation be correct, a gradual or step-by- step 

 upheaval, corresponding to that displayed by the inland 

 terraces. 



I have seen " the Parallel Roads " of Glen Roy and 

 Glen Spean, but interesting as they are, they are not 

 comparable to the terracing of these Norwegian valleys. 

 The causes materially differ. The shores of Glen Roy 



