ee 
THURSDAY, JAN UARY 1870 
THE PROFECTED CHANNEL RAILWAYS 
Il. 
O connect England and France bya railway through 
a submarine tunnel is not a novel idea. From time 
to time English and French engineers have revived the plan 
of tunnelling under the Straits of Dover with some modifi- 
cation or other. Among these the latest and most care- 
20, 
fully considered proposition is that by Messrs. Hawk- 
shaw, Brunlees, and Low, in connection with Messrs. 
Talabot, Chevalier, and Gamond. The scheme of these 
engineers will be best understood from their report to a 
committee of promoters, and we will give those passages 
of the report which are essential for the clear comprehen- 
sion of the plan :— 
“The undersigned engineers, some of whom have been en- 
gaged for a series of years in investigating the subject of a tunnel 
between France and England, having attentively considered 
those investigations and the facts which they haye developed, 
beg to report thereon jointly for the information of the com- 
mittee. 
“‘These investigations supported the theory that the Straits 
of Dover were not opened by a sudden disruption of the earth 
-at that point, but had been produced naturally and slowly by 
the gradual washing away of the upper chalk ; that the geolo- 
gical formations beneath the Straits remained in the original 
order of their deposit, and were identical with the formations 
of the two shores, and were, in fact, the continuation of those 
formations. 
“Mr. Low proposed to dispense entirely with shafts in the 
sea, and to commence the work by sinking pits on each shore, 
driving thence, in the first place, two small parallel driftways or 
galleries from each country, connected at intervals by transverse 
driftways. By this means the air could be made to circulate as 
in ordinary coal-mines, and the ventilation be kept perfect at the 
_ face of the workings. 
“Mr, Low laid his plans before the Emperor of the French 
in April 1867, and in accordance with the desire of his Majesty, 
acommittee of French and English gentlemen was formed in 
furtherance of the project. 
“For some years past Mr. Hawkshaw’s attention had been 
directed to this subject, and ultimately he was led to test the 
question, and to ascertain by elaborate investigations whether 
a submarine tunnel to unite the railways of Great Britain 
with those of France and the Continent of Europe were prac- 
ucable. 
** Accordingly, at the beginning of the year 1866 a boring was 
commenced at St. Margaret’s Bay, near the South Foreland ; 
and in March 1866 another boring was commenced on the 
French coast, at a point about three miles westward of Calais ; 
and simultaneously with these borings an examination was carried 
on of that portion of the bottom of the Channel lying between 
the chalk.cliffs on each shore. 
“*The principal practical and useful results that the borings 
have determined are, that on the proposed line of the tunnel 
the depth of the chalk on the English coast is 470 feet below 
high water, consisting of 175 feet of upper or white chalk and 
295 feet of lower or grey chalk ; and that on the French coast 
the depth of the chalk is 750 fee: below high water, consisting of 
270 feet of upper or white chalk and 480 feet of lower or grey 
chalk ; and that the position of the chalk on the bed of the 
Channel, ascertained from the examination, nearly corresponds 
with that which the geological inquiry elicited. 
**Tn respect to the execution of the work itself, we consider it 
proper to drive preliminary driftways or headings under the 
Channel, the ventilation of which would be accomplished by 
some of the usual modes adopted in the best coal mines. 
** As respects the work itself, the tunnel might be of the 
ordinary form, and sufficiently large for two lines of railway, 
and to admit of being worked by locomotive engines, and arti- 
ficial ventilation could be applied; or, it might be deemed 
adyisable, on subsequent consideration, to adopt two single lines 
of tunnel. The desirability of adopting other modes of traction 
may be left for future consideration,”’ 
_NATURE 
& 
Oo 
Ge 
This, then, isthe great Tunnel schemes, which a com- 
mittee of promoters and engineers submitted to his 
Majesty the Emperor of the French in June 1868 ; and we 
are informed “His Majesty was pleased to ‘refer the 
matter to the favourable consideration of his Excellency 
the Minister of Public Works, who appointed a special 
commission to inquire into the subject inall its bearings.” 
This special commission reported in March 1869; anda 
summary of this report on the main question is contained 
in the following three resolutions, viz.— 
“*T. The commission, after having considered the documents 
relative to the geology of the Straits, which agree in establishing 
the continuity, homogeneity, and regularity of level of the grey 
chalk between the two shores of the Channel, 
** Are of opinion that driving a submarine tunnel in the lower 
part of this chalk is an undertaking which presents reasonable 
chances of success. 
“* Nevertheless, they would not hide from themselves the fact, 
that its execution is subject to contingencies which may render 
success Impossible. 
‘IT. These contingencies may be included under two heads : 
either in meeting with ground particularly treacherous—a 
circumstance which the known character of the grey chalk 
renders improbable ; or in an influx of water ina quantity too 
great to be mastered, and which might find its way, in either by 
infiltration along the plane of the beds, or through cracks crossing 
the body of the chalk. 
“* Apart from these contingencies, the work of excavation in a 
soft rock like grey chalk appears to be relatively easy and rapid ; 
and the execution of a tunnel, under the conditions of the project, 
is but a matter of ‘ime and money. 
“ITI. In the actual state of things, and the preparatory 
investigations being too incomplete to serve as a basis of calcu- 
lation, “the commission will not fix on any figure of expense or 
the probable time which the execution of the permanent works 
would require.” 
Having laid before our readers the Channel Tunnel 
Scheme in the words of the originators, we shall now 
proceed to analyse it, and for the purpose we also publish 
a map forming part of the engineers’ report, and 
which we reduce to a scale of six miles to one inch. 
. The first important statement with which we meet in 
the engineers’ report is that under section 2, viz., on the 
theory of the formation of the Straits of Dover. We 
admit that in all probability the Dover Channel was not 
produced “by a sudden disruption of the earth at that 
point,” but we cannot endorse the hypothesis that it 
has been formed by gradually washing away the upper 
chalk. 
In order that the chalk may be washed away more at 
that point than at others, it is necessary that the current 
should be stronger. To begin with the operation of 
washing away, we must have a current, a strong current, 
which could only flow in a valley or channel, previously 
formed either by depression of the surface or by the ele- 
vation of the land adjoining that surface. Whichever 
way we take it, the original channel of Dover must, it 
would seem probable, have been formed by a geological 
disturbance of the earth’s crust. 
The current within that geologically-formed channel 
may have further deepened it, although this is not pro- 
bable, because at the bottom of a channel from 100 to 
200 feet deep, the speed of a current can be but a small 
fraction of its superficial velocity, and this fraction is 
assumed to have abraded chalk rock. 
Looking at the chart attached to the report of the 
engineers, we find a series of lines running from the 
English to the French coast, which are assumed to indi- 
