E. Donsox.—State of Applied Science in Canterbury. 139 
Coast routes, a set of flying levels across the country was taken by aneroid 
observations, a single instrument only being used and the weather being 
exceedingly unfavourable; yet the results compared very satisfactorily 
both with the altitudes afterwards obtained with great care by Dr. Haast, 
and with the actual heights as determined by the spirit level after the open- 
ing of the Otira Road. In laying out the line across Arthur's Pass, where 
the road descends 750 feet in a very short distance measured in a straight 
line, the gradients were determined entirely by the aneroid, the observer 
creeping through the dense scrub on his hands and knees, and fixing the 
position of the line, at every few chains, by the reading of the aneroid; the 
line thus laid out requiring but little subsequent alteration, when the 
clearing of the timber had given an opportunity for the correction of any 
irregularity in the gradients. 
Ratiways.—Passing from ordinary roads to railways, we have to record 
the completion of a first instalment of the Southern Railway, constructed 
under the superintendence of Mr. W. T. Doyne, M.I.C.E., which was opened 
for traffic as far as Rolleston, about fifteen miles from Christchurch, on the 
15th October, 1866. On the Lyttelton and Christchurch Railway, which has 
been open for traffic between Christchurch and the Heathcote Wharf since 
December, 1863, the works of the Moorhouse tunnel have made steady pro- 
gress, only about 240 yards remaining to be driven at the present time, out 
of a total length of 2,838 yards. ; 
Independently of the interest attached to these tunnel works in a 
geological point of view, as affording a complete section through the side of 
an extinct volcano, they are of importance as an example of engineering 
difficulties successfully overcome. 
The syphon employed for the drainage of the upper half of the tunnel 
is probably the longest of which there is any record in the history of tunnel 
works, being upwards of half a mile in length ; whilst the system of ventila- 
tion employed, viz., that of conducting the smoke and foul air through a flue, 
formed by a horizontal brattice, into an upeast shaft near the tunnel mouth, 
has proved perfectly effective. Itis worth remarking, that the engineers of 
the Mont Cenis tunnel have at last found it necessary to employ a similar 
means of ventilation, the supply of compressed air forced into the face of 
the work being insufficient to drive out the smoke which filled the tunnel 
like a series of walls of dense fog. 
It may be laid down as a leading axiom with regard to the ventilation 
of drives mined with gunpowder, that although fresh air may be driven in 
by machinery, so as to produce a healthy atmosphere for the miners, the 
smoke from the shots cannot be driven out, but must be drawn out by 
creating a vacuum in the direction in which the smoke is to be drawn; the. 
