610 Analyses of Books. [October, 
geyser of Iceland seems to vary much on different occasions. 
The highest aCtual measurement given is 212 feet, but as seen 
by Olafsen and Povelson it was estimated at 360 feet ; and Mr. 
R. Allen says that well-informed natives do not consider it at all 
improbable that such a height might be reached. Strokhr, which 
is only about 120 yards from the Great Geyser, does not reach so 
great elevations, the highest measurement being only 132 feet. 
The Roarer, once equal to the Great Geyser, diminished since 
the earthquake of 1789, and has ceased to spout. 
It is remarked that the springs in the Yellowstone Park gene- 
rally present shades of blue, shading sometimes into green. 
The same colours are found in Iceland, Java, New Zealand, in 
faCt in every region of hot springs. Many lakes and rivers also, 
in Switzerland, California, and Norway, have a more 01 less 
decided blue shade. Pure water is, in faCt, distinctly blue if 
seen in a sufficient depth, though in ordinary streams and pools 
this colour is annulled by the brown shade due to decomposing 
organic matter. 
The volume is profusely illustrated, and the views convey 
striking instances of the gorgeous, yet at the same time weird, 
character of the scenery. 
Canal and Culvert Tables, with Explanatory Text and Examples. 
Revised Edition, with Additional Tables. By Lewis D’A. 
Jackson, C.E. London : W. H. Allen and Co. 
The current of events is directing public attention much more 
strongly to canals than has been the case for the last half- 
century. We are beginning, now the gloss of novelty is worn 
off, to perceive that railways — however necessary for the rapid 
conveyance of passengers, of the mail-bags, and of perishable 
goods — cannot, as far as ordinary heavy merchandise is con- 
cerned, compete in price with canals. Men of business are, 
therefore, awaking to the truth that our recent negleCt of the 
facilities for inland navigation has been a mistake. It is seen 
that by the application of steam to boats, on properly constructed 
canals, an average rate of speed can be reached fully equal to 
that of a goods’ train, with the advantages of easier rates, and 
of delivery and collection at almost any point in the country 
traversed. 
Hence we think that Mr. Jackson does himself and his subjeCt 
less than justice when he says, in his Preface, that “ the portions 
applicable to culverts perhaps alone being likely to come into 
frequent use in England.” 
