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BLAXLAND'S PROPELLER-FARTHER EXPERIMENTS.
451 Blaxland's method of working, must veral other particulars. We have thought be taken together; they are part and it, therefore, due to the importance of parcel of one patented invention ; they the invention, to avail ourselves of the are legally “one and indivisible," and present opportunity to describe it anew, must, in all fairness, be so considered. and with more completeness, in all its
The description which we gave of the details; and to save the trouble of referinvention in our last volume, did not ence to the back volume, we have inpoint out with sufficient clearness the im cluded in the accompanying engravings portant part which the gear-work plays three which were formerly given.* in the affair, and was also defective in se
1.- Of the Propeller.
part of the keel forwards of the rudder post, The principle on which Mr. Blaxland which inclined planes work in the water constructs his propeller, is thus clearly below the water-line, in an opening formed explained in his specification :
in the dead wood of the vessel, but without “One or more inclined planes or propel- plane or planes, so as not in any way to be
any bearing or journal beyond the inclined lers are to be affixed at right angles to a re attached to the rudder post. In order to detervolving horizontal shaft placed over the after mine the angles at which the inclined plane or
planes is or are to be fixed to the revolving • For the means of giving this more complete horizontal shaft, I draw a straight line, the description we are indebted to Mr. G. Steinman, the owner of the Swiftsure, and part-proprietor of Mr.
length of the circumference, as shown in the Blaxland's patent, to whom the highest praise is diagram, fig. 10, from 1 to m 56.54 inches ; due for the spirit and liberality with which, regard then I set ont the angle at which I intend to less of expense and trouble, he has persevered in obtaining a fair trial for the invention which he has
set the first or outermost inclined plane, and taken under his patronage.
raise a perpendicular from the length of the
circumference, and at that point where it
Explanatory Figures. intersects the angular line which is deter
Fig. I is a section or side view of the after mined upon, will be the distance passed
part of a vessel, showing the invention as through at one revolution. Then I draw a line parallel to the base line, and in like
used on board the experimental boat Jane; manner set off the other different distances,
a is the main driving shaft from the as from 1 ton, 50•26 inches the circum.
engine ; b the driving drum ; c the interference. I then find that an angle of 33° is
mediate friction wheel; d the driven necessary to give the same distance advanced, drum; e the strap; f is a pipe car. and in like manner I proceed to set out for ried to any convenient part of the vesthe different circumferences or diameters re sel, through which a mixture of oil and quired. I prefer, however, not carrying it tallow is applied to the gland or bearing further to the centre than where an angle of where the revolving shaft passes through 45° would be required to give the distance. the vessel ; the mixture being put into a I rivet the inclined planes, which I prefer cylinder, in which a piston is fitted and divided into three or more parts, each part loaded with a weight so as to force it into being separately riveted on to an arm,
the gland or bearing. The propeller is here shown in fig. 7.
shown with an undivided inclined plane.
Fig. 2 is a section through fig. 1, 2.-The Gear Work.
showing the mode of tightening the The speed of the revolving shaft upon strap by means of the friction wheel and which the inclined planes are fixed is screw as applied on board the Jane ; got up and maintained in the following the letters in this fig. correspond with manner :
those in fig. 1. I place an intermediate friction wheel Fig. 3 is a section through the stern end between the larger driving drum, and the
offig. 1, but showing three series of divided smaller driven drum, as shown at figs. planes, each divided into three parts. 1 and 2, which friction wheel revolves Fig. 4 shows a mode of keeping the with the driving drum, and is again borne drums parallel to each other, when the and communicates its motion to the driven shafts are out of a parallel line, with one drum. I bring the friction wheel into or out intermediate friction wheel, and of the line of centres by means of a screw as
Fig. 5 the same with two intermediate shown in fig. 2, whereby the strap or band e, friction wheels. which passes over the said driving and driven
Fig. 6 shows the strap and band when drums may be tightened or slackened as oc
made to pass upon the surface of one casion may require. In order to keep the
intermediate wheel. drums parallel to each other when the shafts are out of a parallel line, I leave a spherical
Fig. 7, is an end view of a propeller boss upon the shaft, and make the drum in
with four series of inclined planes, each two parts, so as that the boss of the two
divided into three parts. parts of the drum may fit the boss on the Fig. 8 is an end view of the propeller shaft, and put them together by means of
used in fig. 1. screws, so as to form an universal joint ; Fig. 9 shows the mode used for a and a clutch, or driving coupling, is keyed bearing, where the propeller shaft on to the shaft to carry the drum round, as passes through the vessel when it is shown at fig. 4. The strap or band may be required that the same may rise and fall. made to pass upon the surface of the intermediate wheel, as shown at fig. 2 ; when it may be required for the propeller shaft
Application to River and Canal Purposes. to rise and fall with the tightening and slacking of the strap, a bearing is used as On Tuesday, the 24th ult., a trial of shown at fig. 9. I grind the part h, into the Jane was made in the River Lea, in the socket i, to make it water
the presence of the following gentlemen :tight, but at the same time to move freely
Ezekiel Harman, Esq., of Theobalds ; in and out of its socket and the part h may be kept up to the spherical part of the
Thomas Brewin, Esq., of Birmingham; W. shaft by means of a spring or springs, but I C. Mylne, Esq., Engineer to the New River do not consider it indispensably necessary Company ; Lieut. Webb, of the Ordnance that the propeller shaft should rise and fall, having in my experiments allowed the upper
Department, at Waltham Abbey ; Mr. shaft a only to rise and fall with the tighten
Austin, Engineer to the Ordnance Mills, ing or slackening of the strap."
Waltham Abbey; Mr. Griggs, Surveyor to
ON EELS AND EEL LINES-BY COL. MACERONE.
453 the river Lea, and Mr. Gunner, store-keeper lakes, and ponds. Its natural history to the Ordnance.
is very curious, and but little understood. The boat was steamed from Enfield Lock The salmon, shad, grey mullet (cefalo), to Ware, a distance of 141 miles and back,
smelt, and some other fish, reside mainly and proceeded with hardly a ripple in her
in the sea, and only frequent the rivers wake, whilst a small boat towed by a power
for the purpose of spawning; but the
eel brings forth its young in the sea, ful horse which followed her cansed so much which soon ascend the rivers, wherein surge and commotion that her gunwale was they remain until the age of propagating frequently within an inch of the water. maturity. This age is about four years, When the horse-drawn boat was made fast
when, in large rivers like the Thames, to the Jane, the surge and commotion ceased.
they have acquired the weight of from
two to three pounds. At this period, The Jane remains at Enfield waiting a
upon the first autumnal floods, they special general meeting of gentlemen in. hasten to the sea, never more to return terested in canal navigation, from all parts into fresh water. Thus it is that they of England, which is to be shortly held
are then taken in such numbers, and there, to take the applicability of the Blax.
all nearly of the full grown size, in cer
tain wicker or reed" apparatus placed land Propeller to Canal purposes, as well as
across the streams. other matters, into their consideration.
In large lakes and waters that have no communication with the sea,
often found of a far greater size than in EELS LINES-BY COL. any river, because they are compelled to
remain therein, and continue to grow. There is some confusion in the Latin In the lakes of Albano and Nemi, near terms for eels; Anguis, Anguilla, Mu Rome, there are eels of ten to fifteen rena, being often applied to the same pounds weight. In the year 1827, an animal.
eel was caught in its attempt to escape To avoid technicalities, I will observe, from a lake in the centre of the island of that in this country we have two kinds Mauritius, which weighed twenty-seven of eels; the small dark blue eel found pounds, and was presented to the go. in canals and muddy rivers, and the large vernor, Sir Lowry Cole. On the coast silver eel abounding in the Thames, &c. of the Adriatic, is the city of Comac
The Murena is called in England lam chio, in the Papal States. It is surprey; it is of a bright yellow brown with rounded by extensive lakes and swamps, black streaks, much after the fashion of with several estuaries to the sea. The some serpents, and is thicker, in propor staple article of trade at Comacchio contion to its length, than the common eel. sists of eels. It is in October and No. In lieu of gills, it has seven holes on vember that the great migration of eels each side, which answer the purpose of takes place. The class of mature ones, separating the air from the water, like i, e., from three to five pounds, hasten the gills of other fish. The only dif. to quit the lakes for the sea. In order ference is in the division of the open to intercept them, meandering labyrinthings for the water into the gills.
like constructions of slender reeds are The greatest supply of these Murene, established at the estuaries, into which or large lampreys, is about Puzzuoli, the eels freely enter, but cannot find eight miles from Naples, where, it is their way out. No small ones ever atsaid, that Lucullus had his marine fish tempt this departure. The quantity thus ponds, into which he cast the flesh of taken is prodigious. The entire populahis offending slaves ! I have never
tion of Comacchio and its dependencies caught any lampreys of more than four subsist mainly on the produce. The pounds each. Like the smaller lampreys labour is divided into sections. One set they have no bones, but only cartilage, of men build the labyrinths, and take and are exceedingly nutritious food. the eels. Another section, including They have never been known to reside many women, chop them into pieces and permanently in fresh water.
roast them. Others make barrels for But the common eel is only generally their package. Another set pack them known during its residence in our rivers, up with bay-leaves, salt, and vinegar.
Lastly, another class collect the oil which would have thriven wonderfully in this falls from the roasting eels, of which a lake, but I could not easily obtain any. large quantity of good soap is made. A Now a few words on the generation of number of clerks and exporting agents the eel, which I believe is a point still keep the accounts, the amount of which unsettled amongst naturalists. One hot is equitably divided amongst the commu summer's day, in June, 1820, as I was nity. I have been told that the value proceeding up the river Thames from of the eels of Comacchio exceeds 40,0001. Ditton to Hampton, my attention was per annum, which appears to me not much excited by an extraordinary appearoverrated, when we know that there is ance of the water on each margin of the scarcely a town or village in Italy that river. For a yard or two in breadth it does not consume scores and scores of had all the appearance of soap suds. On barrels of them every year, especially in investigation I found the phenomenon to Lent. Many millions of persons make be caused by countless millions of young a point to sup upon these eels on Christ eels, about as thick as a straw, wriggling mas-eve. They call them “ Capotini." their way up the stream, where they had Spain and Portugal also consume a large to contend with the least resistance of the quantity.
current. Such is the anxiety of the eel when On arriving at Hampton Court, a vast mature to quit the brooks and rivers for dense column of these young eels dithe sea, that I have often taken them verged from their course, and passed up when crossing a field of wet grass, which the river Mole. In the lock it was diffi they can accomplish to a great distance. cult to say whether there was more water
Near Naples is the celebrated lake of than eel! Hundreds of boys and women Agnano, in which no fish existed when were busy with cullenders, saucepans, I first knew it, in 1806. Its banks are sieves, &c., taking out thousands at a generally covered with reeds and rushes. dip, with which they told me they made Close to this is the lake Astroni, at the most excellent pies and cakes, with batter. bottom of an extinct volcanic crater. Arrived as far as Hampton-common, I The crater itself is about four miles in found a vast crowd assembled to witness circumference, filled with the finest oak a prize-fight between Scroggins and and chestnut timber. A strong wall Turr and there I met with my old crowns the summit of the bowl or "cra acquaintance Captains Bastard and Horter," to keep in the numerous wild boars, ner, of the R. N., to whom I pointed deer, and hares which inhabit it. The out the eel phenomenon. My fisherman beautiful little lake in the centre teems and others called it Eel-fair, and told with carp, roach, and eels. Of these, I me that it only occurred once in three or transferred many hundreds to the lake of four years. Any pond might have been Agnano. Observing that the banks of well stocked by one dip of a bucket. I the latter lake swarmed with myriads of had occasion to stop at Hampton to dinfrogs, I procured many pails full of ner, when I took leave of the Eel-fair, young eels about as big as a straw, and which still pursued its course. cast them into the lake. Frogs are the I have above remarked that when eels favourite food of eels, and here each eel arrive at a certain breeding size, they might, in summer, eat a thousand a day. quit the river and hasten to the sea. The eels thrived prodigiously, as did also This takes place in the autumn, after the carp and roach. These young eels rain. The 'hames' fishermen place cer. I procured from Patria, the ancient Li tain large baskets, called " bucks,” across turnam, and, including carriage, they the side waters, into which the eels are cost me about a shilling a thousand. I conducted by the stream, and captured. have no doubt but that with such abun It is my perfect conviction, founded dant frog food, and such an extent of on much and long observation, that the water with no escape to the sea, there eels which get to the sea never return are now thousands of eels of very large to fresh water, but therein breed, and, dimensions. Six years after my colo supplied with most abundant food of nising operation, I caught several that small fish, become what are called conweighed three and four pounds each. gers. Congers agree with the river-eel The carp had grown to ten pounds; the in the number of their vertebræ, their roach to above a pound. Pike and perch teeth, fins, and every particular except
ON EELS AND EEL LINES-BY COL. MACERONE.
their colour being lighter; but we all know that the colour of fish is always influenced by that of the water, and of the bottom on which they live. Pike and perch, for instance, taken on a bottom of green weed, will be of a beautiful green; when taken off sand or mud, they are brown and dull. The dace of the Tiber, instead of the beautiful silver hue of those of the Thames, are of the dull sand-like texture of the Tiber's waters and bottom.
I do not know whether the majority of naturalists incline to the oviparous or the viviparous generation of the eel. That the lamprey is oviparous, I have had proof. But I can show that the eel, at least the large“ silver" eel, is viviparous. In proof of this, I beg attention to the following facts.
In September, 1825, I was fishing at Shepperton, a village situated between Walton and Chertsey. A fresh of water coming down the river, I caught many very large silver eels, and in order to have them at my disposal when required, I placed about half a dozen of them in a properly constructed basket in the well of my punt. I did not attend to them for some weeks, but upon opening the basket to take out one or two for dinner, I was agreeably surprised to find several scores of young eels, thinner than a straw. This was in the evening, and the next day the greater part of them had ab. sconded through the interstices of the wicker-work, and the holes in the punt's well. However, I secured about fifty, and put them into a pond belonging to Lord Lucan, at Laleham, where, by the by, they will not have remained, as the pond has a communication with the Thames, and so to the sea. By this time my little eels have become huge congers, and sent up several eel-fairs such as I have above described.
With respect to the best method of catching eels by hook and line, I intend to speak fully in a work I shall publish when I may have the means, intitled “ An original art of Angling, with new and improved methods of constructing fishing-rods, and all sorts of tackle." But, en passant, I may here observe, that the best baits for eel night-lines, are portions of skinned frogs. The small fish cannot pick these off the hooks as they will lobworms; and the whiteness of the bait draws the attention of the eel towards
it. An eel night-line consists of a main line as thick as a quill, twenty or more yards long, according to the extent of the waters fished in. A diagonal position is generally the best. First, because it embraces a more extended line ; secondly, because when in search for food, the eels are prone to prowl near to the banks. The main line should be woven, not twisted. The hook lines should be about two feet long of plaited silk, and attached to the main-line by a slip-knot, about four feet apart. When a twisted main-line is used, the twisting and untwisting of it caused by the water, winds the short hook lines up to the hook itself. When you take the eels off the line, just pull the slip-knot, and let the eels fall into a recipient with the hooks within them. At your leisure, you may then feel the position of the hook, and passing the point outwards, draw it and the hook-line, like a needle and thread, from the side or throat of the eel.
The eel is the most voracious of freshwater fish. They will greedily devour dead animals or their intestines, which a pike or a perch will not touch. Hence, in some parts, eels are caught by putting chickens' guts into a faggot, and suddenly pulling it up in the morning, when many eels are found entangled in the sticks.
About eighteen miles from Naples, is the celebrated palace of Caserta, the largest and most beautiful in the world. At about a mile from the back of the edifice is a range of rocky hills, appendages of the Appenines. A most stupendous aqueduct brings thither a stream of crystalline water from a distance of twentysix miles, passing in its course across the valley of Maddaloni over a bridge of three tiers of arches 140 feet high. This water falls by a beautiful cascade into a rectangular lake, extending to the palace, being, as I have said, about a mile in length. Besides trout, carp, perch, and tench, there are in the lower and stiller parts of the lake, an immense number of large eels. To minister to their eelships' habits, a number of earthen tubes, like chimney-pots, are piled here and there along the bottom, in which they usually reside during the day time. But in the summer, at midday, a man arrives with a wheelbarrow full of frogs to feed them. No sooner do the eels hear the sound of the wheelbarrow, than they sally forth from their pots, swimming