FISH CULTURE AT HOME.

Press, Volume IV, Issue 448, 6 April 1864, Page 4

FISH CULTURE AT HOME.

In pursuance of the same subject the Time* of Jan. sth, furnishes the following particulars of the advance made in the art of pisciculture in Great Britain and Ireland:— It is now over two years since we noticed the pro* gress made in salmon breeding in the ponds at Stormontfield, on the river Tay, near Perth. Aβ we then stated, a breeding at these ponds can only be taken once in two years, because in circumstances developed in connexion with the natural history of the salmon, which shows that only one-half of a brood migrate to the sea at the end of the first year; and then being only one reception-pond at Stormontfield there was the imminent danger of any newly-hatched fry being devoured by the two-year-olds, which would b» in waiting to make their exit to the sea. This blemish of the Stormontfield salmon nursery will, we believe, be speedily remedied, as another reception-pond is about to be added to the suite. This will enable the conservator to produce a hatching of 300,000 salmon every year. These will be protected in the ponds till they change from the parr into the smolfc ifcage, at which time they become imbued with the migratory instinct, and seek to visit the salt water. Many queitions connected with the natural history of the salmon have been now set at rest by the experiment! carried on at Stormontfield. It is certain that the parr becomes a smolt, that the amolt in due tim» changes into a grilse, and, if not killed prematurelffor we kill even our virgin fish—that this latterbcomes a salmon. These piscicultural experiment also settle the dispute as to the fecundation of the fish—viz., that it is an external act entirely, hene» the art that has arisen in France and elsewhere of artificial spawning and protracted breeding. The total number of iish introduced into the T»y through the operations at the breeding ponds ha» been in round figures something like a million and i quarter, and the rental of the river has grown inconsequence ; an increase of 10 per cent, being due to the ponds—the expense of these being only about £1 per week. Wβ have the authority of Sir Williua Jardine for stating that pond-bred fish suffer no deterioration from the circumstance of their birth and artificial nurture; on comparing the fish of the (Stormontfield) ponds with those in the river, that gentleman found a remarkable similarity and agreement of the different stages in all respects with those of the same age. The first hatching on the artificial plan took place at Stormontfield in November and December, 1863, the operations being conducted by Mr. Bamsbottoin, an eminent practical piscicultural manipulator. It was eminently successful, the whole of the 300 boxei being stocked at the rate of 1000 eggs per box. The fifth hatching, which was performed in November and December, 1859, was also highly successful, Miulting in the addition of 250,000 sraolts to the salmon stock of the river Tay. The whole of the proceedings connected witli this salmon nursery at Stormont* field have been watched with great interest by the naturalists, as well as by some interested in the development of the salmon fisheries in, their commercial aspect. Various experiments have been Jnade from year to year by Mr. Buist, the conservator of the Tay fisheries, with the view of ascertaining the rate at which the salmon grow. These ponds afforded him ample facilities for watching and identifying the fish, which were marked in various ways before being let into the river. The pond-bred salmon werefouaa to grow very rapidly. Of salmon fry liberated for their sea voyage in May many were taken in July of the weight of from 3lb. to 71b. The most cunoul fact in the natural history of this valuable fish i*# that of two salmon spawned at the came time on* may visit the sea and become a grilse of 61b. weight while the other is still a little parr of i oz., and in the succeeding 12 months the one may be a nicely grown salmon of 12 lb., while the other, having only just assumed the scales of the etnoJt, is timidly venturing down the river to pay its first visit to the sea. The perfect results of the latest hatching at thew ponds will not be ascertained for a few months yet. > The spawning was begun on Martramae-day, 186% and was concluded on the 2d December °T™* year—the operation ot spawning ie thus protracwa from the difficulty of obtaining fish with the no» and roe perfectly ripe. Mr. Buist (the conservatory, found it necessary to the success of that year! spawning to capture 119 full grown salmon, and *~* grilses, and out of these 18 ealmon and 2- gruiM were selected for manipulation and the number « ripe eggs obtained from the lot was 275,000. Jao» of the fish spawned were females, and it m*y J» , noted here that the milt of a single male fl «*"£ fructify the eggs of two or more females. AOet» eggs, with a slight per centage of waste, all <£*?•" life, and in the comparatively short space of former hatchings having taken from 15 to 25»| longer. The ponda at Stormontfield are WaUW«V situated on the banks of the Tay, about five mw» from Perth, and are well worth visiting, either mw spawning or the migratory season. ? etel \ the, keeper, thoroughly understands the art « V*> culture, and receives visitors with great wben "£ anee is necessary in visiting the ponds to hire a pf at Perth, as there is no railway on the poua ■"» the river. sfawmoniIncited, no doubt, by the euccose of the »*f"~J, field experiments, the lessee of » ealmon fj 8 the Kiver Ugie, in Binnsbire, ha» co^? , ing on a small scale. He has modelled ba those near Perth, and has provided c^ om for the hatching of 10,000 egg». This e*?*""^

5== "~~ "Tonly in its infancy need not be further bfingfj° nt present. Jludca w>. nnol her exponmeiif m salmon hrrrd- , tfeVn°V ; cftrr i r d on iv the Stewartry of Kircudia* D iniilScotlan;!; but it is not yet rip,- for bra? ,, ! , . , (fcjcript , ', , nneni tion» in salmon hi-ceiling are B nt l h *4 on 'ill lrcliiml. Tlu-y u vo -.he U-st us magnitude, an,l in the f.u-t of their ■ Iroduced salmon into rivers which were hiTin/r , ?'- r : / . l , w ible to thrA fish. Tlio fisheries we forniwlv ina £*j lOgo of the Mcssre. Ashwonh, who Jlade to A. in all ql , e!J tioTis relating to piscine of all kinds or fish. enWW* * nt J, "c by memw of arlilJcial breeding, iiiend "onpvvnliioof thririi.ihcri f s twenty fold, creesed tlic l •;,„„, ts , a most economical one it Oncof m ' ! cons j s ted in stocking a suite of roUS V wm with nearly SOO.OOO at » cost of j,r(«aing-DOiv ftt merit of these gentlemen £18 dtorhii?- ,j r ] iavin g converted Loughs Mask and consist* in , po nds—pond* embracing an area Crra into «im A cv( of 2s,OOOnereson toiricrof ])revontod through a n.iru point thnn Jo^h <be asoent. oi; i ' ]ioul , isi b l lS vorth expects in a short . Corrib, an< \ lion w ill br abundant in this new time that the s passage alluded to above ii field of water. i en ,,tl), anu was ronstructed at an noerly two nui« = but nn nniple intcri , rt will in expense out]ay fijr the , due time be Mr Aflhworth that it is much more profitable to breed galmon than sheep. at work. In a recent Mr.AeWh'isj (lWe nro now iirtiflca n v wmm umcat,on « .v, naufti thc propagates } Ma 3 ] . ;, end Plfl ni g fl i fisheries extend over a Large tract of ' **"»> G te LouSof Afa.k and Curra being fed by country, "iP tributary streams so fur as salmon B °r Concerned, and among his other feats, and sure, Mr. Ashworth, in adioDiakcWHuranct . dhi ? ,to ! , SSt iH"fiell transport, the live fish ffometreamtos mhnm {n & r intendent, con^ k in onlcP to place them iv the a"ributarj-to Lough Mask a lough v I £ means of the cut connecting it with Lough which, b £ rae ° communication with thc sea, an WJS. Wily e ß9 ential to salmon life ; and the ° J<! «of Mr Ashworth's experiments was acknow- ,' U j CC< T to be complete when the sraolts were seen £tah.the sea P in April last. On the principle, "Fish Culture in fl Sβ ,, which recently appeared in the Time, , it n£Z as well to state here that the French people f II Hnde of fish, whether they bo from the sea, & rilerthelake,or the cannl. In Scotland and Kdtiie salmon only is bred artificially, because ftfiML Tiluabb and money yielding animal, and no Si flili « regarded in that country as being of «l e except for sport. In France large quantities £*£Ld «a eaten , hut in Scotland and in le parts of England, the people have such a hor"r of that fish that they will not touch it. This of Sm is a mere prejudice, as the eel is good for food JnT very hich degree. In all Roman Catholic 1 fast days that fish food Soomee to the people an essential article of diet; in France this is so, and thc consequence is that a ffSodmany private amateurs in pisciculture nre to bo found throughout the empire; but the mission of the french Government in connexion with fish culture is apparently to meddle only with the rearing end eocliinatizing of the more valuable fishes; it would be a waste of energy for the authorities at Huninßue to commence the culture of the carp or perch. In this Protestant country there is no demand I* |he commoner river or lake fishes, except for the ' purpose* of eport; and with one or two exceptions, BU&M the Lochleven trout, the clmrr, &c, there is do commerce carried on in those fishes. One has but ■ to visit the fish maFkot at Paris to observe that all kinds of fresh-water fish and river orustactea are there ranked as saleable and largely purchased. Some schemes for the extension of pisciculture m England are now being matured. Dr. Buckland has himself desoribed in a lecture (reported in The Times) hit oxperimonta of fish hatching in the Thames; how they will succeed must be left to time to delelope. If a great series of breeding ponds were constructed to feed the Severn, it would tend to the multiplication of our finest salmon, aud assuredly raise the fish rental of that fine river to a very high point.

/ Thb Twin Screw System. —The success which hw attended thp adoption of tho double or twin «crew principle in England and America during the past three years has invested it with great interest. To Captain Carpenter, K.N., wo are undoubtedly first indebted for the introduction of tho twin "Screws; but the-first advance of moment in its practical demonstration was made by Mr. G. Rennie in 1852, followed up in 1857 by the same firm, .in constructing several gunboats on tho same principle for Indian river service. From some cause, jjpFprer, difficulties appear to have existed, for no success eeetus to have been attained, as the principle was not followed up, and a strong feeling certainly existed against its adoption for either nercantile or warlike purposes. Tho single screw, "with all its acknowledged faults, accordingly held _.. ite own against all comers. The double versus single Mrew has been a subject of strong controversy at the meetings of the Society of Arts, the Royal United Service Institution, and other places where wch matters are discussed, as well as of lengthy (Jpnpepondence and editorial articles in tho prafes* Bonal journals, especially since the Messrs. Dudgeon, a Millwall, have adapted the principle, and have ■ begun to launch from thei? building : yard nearly one double or twin screw steamer per month. The doings ?f these Teasels on their trial trips have been recorded to these columns, and now the Admiralty have Mopted the principle in the construction of some ironplated gunboats which are about to bo laid down for we Koyal Navy, taking the data obtained by their - officers from Messrs Dudgeon's trial trips for their guide. Through this long interval, however, of parwand complete success for the twin screws, Captain ' ihT** E ' S y™ onds > RN « a nephew of Sir William eytaondfl, once surveyor of the navy, has been their jjW earnest and persistent advocate, and the triumph fl> Aβ twin jcrejv j», in fact, the triumph of the plan wat officer has so lopg advocated. It is, however, doubtful how far at present the twin may supersede »c angle screw. In the Royal Navy it may possibly euly be adopted in vessels specially built to carry a oeny armament and large engine power at a modcttto draught of water, mid which may bo designed *w operations on a lino of coast, or oil" harbors—as a (»»»t defence vessel, in fact, and therefore requiring *B9s«of turning ehgrtly suph as only two screws -~ lUf lTe " ** however, to say where the ; ™c can be drawn, for draught of water and powers W mjmoßUTring are of equal importance with speed. vm the 22ad of April last, at a meetiug of the Society °*, •* Jrte * Bear-Aduiiral the Hon. Joseph Denman, . & the chair, said, with reference to our large doubt two or three ships of ™** er »«e would be fatal antagonists to such vessels •«e Minotaur or Northumberland, if the smaller ™*w possessed a superior power of turning, by ■"jWs of double ecrews." Turning, however, from 22»n to fiicu, it will be found that the Americans ?"" T *«7 largely adopted the twin screws for their The loss of the ironclad ram Indianola ""•wwbuted, by tho accounts in the American toS a <,inabuit y to mancpuvre." The writer »ta feU a P r °y t0 two BmuU gwnt ,oll * B having of turning t<, v. high degree. They could fclnT ■ Qn ono Bifl e» tl'on on t»e oUier, till the WT ?laUt Was beaten t0 dpatll -" ' I]ie9C two S" n * J3jere driven by twin screws. The Nnugutuok, »»d « 'T rican B un boat, i 3 fitted with twin screws, t, *ria» r T> a 2 °°-Po"iider Tarrott gun on a fixed b^? , «y Hie power of her screws the vessel is fc*» of fi otl ject, and the gun thius brought in a ■ w «». Tl le j o j m Xeleon, a vessel used for V,..

transporting the mail trains across the Dehwar S^nr: ,nVenbytwin •"«»». and lit™ for end at every trip, in order to dcliv« the train", the same end lt entered. She is 223 foot lon Ja nd sated to often perform the manoeuvre ina^tron current cbo«d «th ice in from Inun. 20see. to lm£ Jlkee. A twin vessd is now building , n Amere to mount two monster guns of fifty tons each at «r int'T.' ? ! bC °" fked «"Tiaff", will be fire< at point Wank range, and will be brought to bra upon hie object fired at, like the gun of the Naupa t«cK, by the screw revolving the ship. This is tin position of the twin screw system in Englan.l nnc America at the present time, and the civil war nov ra S ing in America will supply the means of teslim Us usefulness for ships of war. In a paper read bi Uiptam Symonds on twin screivs in April last, thai ofheer advocates double keels unri rudders for twir screw vessels, and gives as his reasons that by apply ing twin screws to single keel ships of tlie "present form the intervening dead wood is a serious obstacle to their perfect action ; it divides and materially reduces the column of water coming to the inner arms of the mtov.i, increases friction, and causes a series of shocks that produce vibration. The vessels which Captain Symonds and Mr. Roberts, C.E., conjointly propose for construction for twin screws are designed for double keels, with a rudder in the line of each keel, and nearly in a line with each screw shaft, with the two keels cellular, and a cellular bottom, worked up into the engine frames for strength. These propositions, however, nre purely professional, and we feel confident that with Mr." Reed in the oflice of chief constructor of the navy, they, together with the whole principle and adaptation of" the twin screw system, will receive Jthat consideration which their importance demands.— The Times.