HARDWICKE'S SCIENCE-GOSSIF. 



135 



W. F. Denning (London : Taylor and Francis). 

 Astronomical students and amateurs of the science 

 are numerous, and they are not unprovided with 

 manuals and other guides. But we doubt if we 

 possess any which so fully meets their wants as the 

 book before us. Its author is an enthusiastic 

 amateur astronomer, who has contributed for many 

 years past much valuable original work to the science 

 to which he is devoted. A completer working manual 

 of astronomy than this, his last-issued work, it is 

 difficult to conceive. It is full, clear, accurate, and 

 yet popular. Many of the chapters have appeared 

 as special papers contributed to scientific magazines, 

 where some of our readers must have met with 

 them. The chapters are as follows :— " The Tele- 

 scope, its Invention, and the Development of its 

 Powers," " Relative Merits of Small and Large 

 Telescopes," "Notes on Telescopes and their 

 Accessories," "Notes on Telescopic Work," "The 

 Sun," "The Moon," "Mercury," "Venus," "Mars," 

 "The Planetoids," "Jupiter," "Saturn," "Uranus 

 and Neptune," "Comets and Comet-Seeking," 

 " Meteors and Meteoric Observations," " The Stars," 

 " Nebulre and Clusters of Stars," &c. The illustra- 

 tions are sixty-four in number, and all are of a 

 high-class character. Paper, type, and binding alto- 

 gether make up a handsome and pleasant-looking 

 volume. 



Geologists' Atsociation — A Record of Excursions 

 made betweefi i860 and 1890, edited by T. V. Holmes 

 and C. D. Sherborn (London : Ed. Stanford). We 

 have frequently thought, when we have received the 

 pithily explained and well-illustrated pamphlets sent 

 out to members describing the places to be visited 

 at each excursion, what a pity it was they were not 

 collected in a more permanent form. Each account 

 is written by a local specialist, and each diagram and 

 illustration is the most interesting in the district. 

 All: England and Wales have thus been visited by 

 members of the Geologists' Association during the 

 last thirty years. Therefore we are unexpectedly 

 pleased to welcome the present volume, which is just 

 the very thing we have so long thought ought to be 

 done. By its very nature, it must be the very best 

 field-manual of British geology yet issued. Between 

 two and three thousand places are referred to in the 

 index, and there are 214 maps and sections. Every 

 student of field-geology should forthwith procure this 

 useful work, which has been excellently edited by 

 Messrs. T. V. Holmes and C. D. Sherborn. 



A SCIENTIFIC PLAINT. 



ALAS, those happy days which we have seen 

 When thou, whose fickleness I now deplore 

 Wert like to concentrated saccharine ; 



Those happy days can come to us no more. 

 When ardent love is strong as H, SO4. 



Thou, like blue litmus in the acid test, 



Whene'er we met, wouldst turn to rosy red, 



And when my love undying I confessed. 

 Thy words were sweet as acetate of lead ; 

 Now truly are they changed to vitriol instead. 



For, turning to analysis improper, 



A quantitative test was made for gold, 

 And when but little else there seemed than copper 

 And scanty silver in the cash I hold, 

 Thy love grew straightway like a freezing-mixture 

 cold. 



Entirely siliceous was thy heart ; 



Thy love was gone. The sequel need I tell ? 

 Betrothed unto another now thou art, 

 Like to the atom H we know so well, 

 Which leaves its own Oj to join the base CI ! 



A. C. Deane. 



THE GEOLOGICAL HISTORY OF THE 

 THAMES VALLEY. 



By Dr. A. Irving, F.G.S., &c., Wellington Coll. 



{Continued Jrom p. 112.] 



The Glacial Period and Since. 



THE probability that England was united with the 

 continent of Europe during Miocene, Pliocene, 

 and Quaternary times, has long been recognised by 

 some of our leading geologists. The sea not having 

 cut its way as yet through the Quaternary isthmus tO' 

 form the present Strait of Dover, the great glaciers 

 of Scandinavia on the one hand, and of Northern 

 Britain on the other, seem to have formed by their 

 confluence a mighty dam, which ponded back the 

 waters of a vast drainage-area of Central Europe and 

 Southern Britain. This, at least, from a considera- 

 tion of all the evidence on the one side and on the 

 other, would appear to have been a most important 

 factor in the glaciation of Central and Southern 

 England. The facts inductively arrived at have 

 been well represented by the late Professor Carvill 

 Lewis of Philadelphia, on a map, which was printed 

 for Section C of the British Association, when it met 

 at Manchester in 1887. The moraines have been 

 taken as indications of the boundary of the great 

 northern ice-sheet ; and the extra-morainic lake, 

 which then covered most of the Midland and 

 Eastern Counties, overflowed by the Upper Avon, 

 line of drainage into the Severn Valley, and by the 

 Oxford Basin and the Pangbourne Gap into the 

 Thames Valley. Much work was done, no doubt,, 

 by the ice which floated down this narrow channel to- 

 widen and deepen it. Professor Prestwich* assigns 

 a deepening of the gorge to the extent of some 220 

 feet to glacial action. This is probably an excessive 



"Journal Geol. Soc," \ol. xlvi., p. 149. 



