1875.] The Channel Tunnel. 487 
which the plane of the globe has been caused to undergo 
great changes. However these inequalities in the earth’s 
surface may have been brought about, the necessities of 
man often demand that the inconveniences caused by them 
to free transit should be overcome, and to this end the e#er- 
vices of the engineer are called into request—it may be to 
bridge over a river or chasm, to tunnel through a lofty 
mountain, under a river or across a channel of the sea. 
Further also the engineer may be called upon to unite two 
seas by means of a water communication, to divert the 
channel of a river, or to guard the coast against the erro- 
sive force of tidal action. Taking a general view of the 
engineering profession, it may be broadly stated that its chief 
and loftiest operations are undertaken with the view of 
accommodating the earth’s surface to the need of mankind, 
either by counteracting the physical effects of forces that 
were in operation in ages past, or by neutralising present 
active forces by opposing to them means of resistance 
designed and based upon a knowledge of natural laws and 
physical science. 
Many works of past ages may fairly claim to be classed 
in the general list given above, of which the most celebrated 
in modern times, at least, will readily present themselves 
to the mind of the reader. There is now, however, a grand 
work in contemplation, for uniting England and France by 
means of arailway tunnel under the English Channel, which 
in point of boldness of design and extensiveness—both from 
a material and commercial point of view—cannot claim a 
rival. 
It is generally admitted by geologists that at one time 
England was conne¢ted with France by land, and formed a 
Peninsula. ‘To all appearances also the separation from the 
Continent has not been effected by any violent convulsion, 
but by the slow and long-continued aé¢tion of the waves. 
It was pointed out in an article that appeared in the 
“Quarterly Journal of Science” for April, 1872, on the 
** Geology of the Straits of Dover,” that, very likely, at one 
time when the land stood at a higher level, and before the 
sea had eaten out the Straits, a river ran from South to 
North through the chalk escarpment, which then stretched 
across from Folkestone to Wissant. ‘The higher streams of 
this old river are the Rother on the English side, the Wime- 
reux and the Slack on the French side. 
The probability of this country having once been a penin- 
sula, and of the land connecting it with the Continent being 
washed away by the action of the sea, was carefully 
VOL. V. (N.S.) 2G 
