SHIPPING INTELLIGENCE. PORT OF AUCKLAND.

Daily Southern Cross, Volume XXVII, Issue 4304, 31 May 1871, Page 2

SHIPPING INTELLIGENCE.

PORT OF AUCKLAND.

High WatkrThis Day.— 3.56 a.m. ; 4.25, p.m. Sunrise and' Sunset This Day.—Morning, 7.8 ; evening, 4.47. Wind anj> WEArnKR. — May 30: Wind, N.E. Weather, cloudy. Phase of the Moon.— Eull moon, June 3,; at 6.6 p.m. \

Arrivals. Duke of Edinburgh, p.s., 52 tons,. Farquhar, from Whangarei. — E.W. Walker, agent.

Departures. Mary Ellen, for Whitiangi,

Thes.s. Herd, from Sydney and Melbourne, is announced to take her departure this afternoon at 3 o'clock. • [ The schooner Ivanhoe, from Mangonui, bring? a cargo of 14 tons' gum, 20,000 feet^ timber, and 40 bales flax. ! The barques Free-trader and Frowning, Beauty are still lying at anchor at the Heads, awaiting a fair breeze to prooeed on their voyages. The barque Janet Dalgleish entered' outwards at the Customs yesterday for Newcastle, in ballast. j The barque Kate, - for Sydney, sailsj to-morrow. * The barque John Knox, from Lyttelton,< arrived at Sydney on the 20fch inst. , The brig Union is now alongside the wharf,, discharging her cargo of grain in good' order. Great improvements have been made from, time to time, and are still making, in the 1 mode of constructing and working steam and other dredges for deepening harbours and similar operations. Of course every new improvement in this direction is not without interest to ourselves, considering that for) years to oomo <lw»dging will be an indispensable operation in our own principal portrwnd its approaches. We extract from a Scotch paper the following :— " A large new dredge, built and engined by Messrs. William Simons and Co., has just been (launched from the London Works, Renfrew. This vessel is the, property of the Clyde Trust, and will be the; most powerful dredger on the river Clyde.' Its dimensions are — Length, 161ft. ; breadth, 30ft.; depth, 104ft.; and it in fitted with two, condensing engineB of 70-horse power. The bucket girder is nearly 100ft. long, and its massive proportions are such as to resist the various strains when working in 30ft. to 35ft. water, and it is fit to raise 5,000 tons per day. A novelty in the working detail of construction are various heavy steel castings, such being considered better suited for severe dredging operations ; and the difficulty of procuring good steel of the necessary irregular form and strength caused considerable difficultyand delay. Another novelty adopted under the direction of Mr. Deaa, the Clyde engineer, is the double slide shoots for discharging, which are driven by steam, and expected to economise both time and labour. ~ This is the eighth vessel Messrs. Simons have built for the diedgingoperations on the Clyde, and on it has been applied every improrement derived from their extensive experience. They have also in progress several other dredgers, one of which (for Dundee) will be launched in a few days. They are also constructing for a foreign Government one of their patent combined steam dredgor. hoppers, which will proceed to sea with its own spoil." An ingenious civil engineer of Marseilles has discovered a mode of using the force of rising and falling tides as a motive power, and he thinks that this new motor can be made serviceable at a great distance from the sea. The name of the discoverer [is Ferdinand Tommasi. The power of the moon's attraction has been used practically for a' long time. The inhabitants of Long Island, while still colonists of Great Britain, ground their wheat and sawed their lumber by moon power. The ocean tides were suffered to fill mill-ponds at flood, and the water so gathered was confined and used to drive undershot wheels after the tide had nearly ebbed. By this process, however, only an insignificant part of the tide power was employed. On every mile of ocean coast the power of the tide is sufficient to raise t3nmillion tons a distance of ten feet twice every day. The tidal power exerted in Delawar eBay alone would more than suffice to drive all the machinery now in use in the world. The chief difficulty in applying tide water as a mechanical motor ia the want of strength in metals. If a cheap substance could be had of ten times the strength of steel this tide power could be gathered up and utilised. With such a metal, a spiral spring, weighing a few hundred pounds, and wound up by the, power of the tide, might be made to propel a railway oar a hundred miles by means of a system of wheels lik» those which are driven by the mainspring of a watch. While tidal' power is in amount scarcely conceivable for its vastness, it is very slow in its vertical motion : the machinery by which it can be made directly available must therefore be of great Btrength and dimensions. The utilising of the tidal motor has long been a subject of study Among mechanicians and inventors, but the insufficiency of the strength. of ' metals has been constantly in the way of a, successful result. The same want is experienced in almost every branch of mechanical invention and improvement. The discovtry of some chemical means by which the strength of steel could, without additional cost, bo doubled, would realise the dreams even of those who seek the means of useful aerial navigation, and it would result in the application of steam-water and electromagnetic power to very many new uses.