394 Chronicles of Science. [July, 
On 25th April last, the first gunboat ever built in Ireland was 
launched from the yard of Messrs. Harland and Wolff of Belfast, 
which is one of six gunboats being built for the British Govern- 
ment. 
Docks and Harbowrs.—One of the greatest and most important 
recent additions to private dock accommodation on the Thames was 
made on 14th March, by the opening of the Millwall Dock basins 
and warehouses ; and on 21st April the foundation stone was laid of 
the first of four large new Graving Docks to be constructed at 
Chatham. 
A new harbour under construction at Torquay, at the cost of 
Sir L. Palk, M.P., is rapidly progressing ; it is intended to extend 
the harbour some 600 feet, and vessels drawing a much greater 
depth of water than heretofore will be enabled to enter it. A con- 
siderable sum is also about to be expended on the improvement of 
Great Yarmouth Harbour. 
Works for the improvement of the basin at Brest were com- 
- menced so far back as 1863, but after sixteen months of persevering 
efforts, the contractor failed to make a water-tight dam. Recourse 
was then had to the compressed air process, and a caisson was sunk, 
having a capacity of 2,427 cubic metres, in which forty men have 
been working day and night in four-hour shifts. 
During the recent visit of the Duke of Edinburgh to Australia, 
his Royal Highness laid the foundation stone of a fine Graying 
Dock at Williamstown, Victoria. 
River Improvements.—The works undertaken for the improyve- 
ment of the Sulina mouth of the Danube appear to have been suc- 
cessful, the depth of the channel having been increased to an average 
of 15 to 16 feet, while the Sulina Pass, formerly regarded as one of 
the dangers which shipping had to encounter, has now become one 
of the best refuges on the coast of the Black Sea. 
Water Suwpply—The Carnarvon Waterworks were opened by 
His Royal Highness the Prince of Wales on 25th April last. They 
are supplied with water from Llyn Quellyn, a lake situated about 
six miles from Carnarvon, and 600 feet above the level of the town. 
The new waterworks at Helensburgh were opened on 26th 
March last. The water is collected from two streams intersecting 
the Mainshill lands before they reach the mossy portion of them 
adjoining the upper, or compensation, reservoir; the lower, or 
storing reservoir is seven acres in extent, and has a storeage capacity 
equal to a supply of 25 gallons to each inhabitant for a period of 
five months. 
An extensive system of works for the supply of Calcutta with 
water are now in course of construction. The supply is drawn from 
the Hooghly at a poimt about sixteen miles north of Calcutta, 
and after being purified is carried by three branches to the 
