268 Progress in Science. [April, 



The mode of using dynamite is to make it into cartridges, and a percussion- 

 cap very similar to an ordinary gun-cap is fixed to the end of the fuse. The 

 cartridge having been opened at one end, the cap is pressed into the dynamite, 

 and secured there by ordinary twine. When used for mining purposes, the 

 cartridge having been placed in the bore hole, and damped with water or sand, 

 the fuse ignites the cap, and the explosion of the cap explodes the dynamite. 

 It has been proved by experiments that a cartridge containing 3 ounces of 

 dynamite has as much disruptive effect as 1 lb. of powder. 



Railways. — The Institution of Civil Engineers has been occupied during 

 the whole of six or seven evenings with the discussion of a paper by Mr. W. 

 T. Thornton, of the Public Works Department, India Office, on " The Rela- 

 tive Advantages of the 5 ft. 6 in. Gauge and of the Metre Gauge for the State 

 Railways of India, particularly for those of the Punjab." The author, in his 

 paper, after referring to estimates for narrow-gauge lines by Mr. Hawkshaw 

 and Mr. Fowler, drew an average between the results of the two estimates, 

 and thus attempted to prove that the saving to be effected by the introduction 

 of narrow-gauge lines into India would not be less than £1000 per mile, which, 

 for the 10,000 miles of State railways already in contemplation, would show a 

 total saving of not less than ten millions sterling in their construction. And 

 it was stated that belief in its superior economy was the one solitary reason 

 why the Indian Government had adopted a narrow gauge for its State railways. 

 After going into a lengthened discussion, having reference more particularly to 

 the Punjab railways, the case for the Government of India was summed up 

 thus : — That by making the Punjab lines on the metre gauge it would save 

 £"530,000, at the lowest computation. To have adopted a light standard, 

 instead of a metre gauge, would have occasioned a waste of a like amount, 

 against which there would not have been the smallest- strategical set-off, nor 

 any other compensation of any kind, except a slightly increased commercial 

 convenience, not exceeding in capitalised value £17,000 at the outside. 



Soudan Railway. — Perhaps one of the most important lines of railway 

 communication now in course of construction is the Soudan Railway, running 

 up the Valley of the Nile, in Egypt, and destined not only to open up the rich 

 country traversed by that river, but eventually it will also doubtless form a 

 very important rival to the Suez Canal route to India, as it will, when com- 

 pleted, shorten the length of the journey by three days. In consequence of 

 the hard rocky nature of the ground, in many parts, the proposal to canalise 

 the Nile so as to form a continuous water-communication past the great 

 cataracts, as was proposed by Mr. Hawkshaw in 1865, will not be adopted. 

 According to the plan proposed by Mr. Fowler, and now under construction, 

 the first cataract will be passed by a ship-incline of 2 miles in length, to be 

 worked by hydraulic power; and at the second, or great cataract, aline of 

 railway — 560 miles in length — will open up communication to the Soudan 

 country, and this will eventually be extended to Massowah, on the Red Sea. 

 a further distance of 430 miles. This new route will be altogether 1900 miles 

 in length. Commencing at Alexandria, on the Mediterranean, the existing 

 railways terminating at Roda will cover 310 miles of the distance. At Roda 

 the passengers will be transferred to light and swift steamboats, and for 600 

 miles southwards the Nile will form the highway for inland traffic. In this 

 distance the first cataract has to be passed, at which there is a difference in 

 level of about 12*5 feet at high, and 15 feet at low Nile. This, as we have 

 said, is to be passed by the construction of a ship-incline, nearly 2 miles in 

 length, on the right bank of the river, commencing at the bottom of the cata- 

 ract between the island of Sehayl and the river-bank, and terminating on the 

 higher level in the harbour of Shaelall, north of the celebrated island of 

 Philae. Rails will be laid on the incline, and suitable carriages constructed to 

 run upon them. The vessel to be raised or lowered will be floated upon these 

 carriages or cradles, the ship and carriage being then drawn over the incline 

 by hydraulic engines driven by water, at high pressure, pumped into huge 

 accumulators, at the summit of the incline, by a pair of large water-wheels 

 placed upon pontoons and moored in one of the rapids of the cataract. A 

 speed of from 4 to 7 miles an hour will thus be imparted to the vessel, according 



