The aquarium : an unveiling of the wonders of the deep sea

Front matter

THE AQUABIUM.

n.i.

THE AQUARIUM:

Preface

YU.

ago, to the effect that an eminent French zoologist, in order to prosecute his studies on the marine animals of the Mediterranean, had provided himself with a watertight dress, suitable spectacles, and a breathing tube ; so that he might walk on the bottom in a considerable depth of water, and mark the habits of the various creatures pursuing their avocations.

Whether a scheme so elaborate was really attempted I know not ; but I should anticipate feeble results from it. The Marine Aquarium, however, bids fair to supply the required opportunities, and to make us acquainted with the strange creatures of the sea, without diving to gaze on them. In this volume I offer to the world a small earnest, just the first fruits, of what may be looked for, in increased knowledge of natural history, from this invention.

In some respects the present Volume may be considered as a sequel and continuation of my “Rambles on the Devonshire Coast inasmuch as it is conversant with similar objects, and as I have made it assume somewhat of the form of a personal narrative ; sufficient, at least, to constitute a link of connexion between myself and my reader, not only in the things described, but also in the feelings they excite in my own mind.

But the subjects of the present work are principally deep-sea animals, as those of the former were chiefly littoral ; and even where the sphere of observation is the same, the observations themselves are quite distinct, and have to do with different creatures. A certain degree of family likeness must prevail in all out-of-door natural history ; but so vast, and almost illimitable, is the field of labour, that industry and faithfulness will always be rewarded by fresh and interesting results.

The following pages embrace a brief History of the Marine Aquarium, as an application of scientific principles

TUI.

PREFACE.

to a definite object ; — my own Experience in collecting animals and plants, with Instructions founded thereon ; — copious Details of the peculiar habits and instincts of such species as I have observed in confinement ; — Sketches of scenery, of local customs and manners, and of personal adventure, made during the prosecution of the employment ; and, finally, an arranged chapter of Directions for the construction, preparation, stocking, and maintenance of a Marine Aquarium.

The Plates which illustrate this volume are its principal peculiarity. I have endeavoured, — in a manner hitherto, I believe, unattempted, — to represent marine animals, with their beauty of form and brilliance of colour, in their proper haunts, surrounded by sub -marine rocks and elegant sea-weeds, as these appear when transferred to an Aquarium. They have been printed from stone by Messrs. Hanhart, who have not spared all the resources of that beautiful art of which they are the acknowledged masters, in reproducing my original drawings.

The wood-engravings are by Messrs. Whymper, and represent the Coast-scenery in the vicinity of Weymouth.

P. H. G.

London: April , 1854.

Contents

i

Chapter I

Return of Spring — Plight to the Coast— Weymouth Bay — Its Grandeur — Portland Breakwater — Its Utility — Harbour of Refuge — Aquarium at the Zoological Gardens — History of the Scheme — Gradual Enunciation of the Principle — Priestley — Ellis — Daubeny’s Researches — Ward — Johnston — Warington’s Experiments — Their complete Success. Page 1 — 13

Chapter II

Reconnoitring — Walk along the Beach — Belmont Bay — Shingle unproductive — Sea-grass — Lucky-stone — Power of Memory — Byng Cliff — Rocky Ledges — Promises— Scene from the Cliff — Steamer ‘ Contractor’ — Birds and Insects — Oil Beetle — Loon — Peculiarity of Tide — Collecting Sea-weeds — Mode of Operation — Fissures — Delesseria — Chondrus — Laurencia — Oar weeds — Dulse — Chylocladia — Coralline — Ulva— Cladophora — Method of Dislodgment — Its Risks and Difficulties — Collecting Animals — Yellow Winkle — Periwinkle — Its Usefulness— Confervoid Growth in Aquarium — Removed by the Mollusks — Their manner of Eating — Periwinkle’s Tongue — Its Action and Efficiency — Weymouth Anemone — Its Varieties— Black Sand- worm — Yellow Doris — Cowry — Hairy Crab — Lobster Prawn. 14 — 39

CHAPTER HI.

Craving for the Remote — Visit to Portland — Wilderness of Stone — Barren Shore — Tansy — Cowslips and Hyacinths — Burnet

X.

CONTENTS.

Rose — Spurge — Land Shells — Garden Snail — Banded Snail — Heath Snail — Silky Snail — Stone Snail — Elegant Cyclostome — Reasons of hidden Things discoverable — Glory to God in Praise — The Broad-claw — Its Manners — Use of the Eoot-jaws — Their exquisite Structure — A living Casting Net — Use of the hind Eeet — A Dredging Day — Quay Scene — Nature and Use of the Dredge — Oyster Dredge— Naturalist’s Dredge — Keer-drag — Roman Advice — Jonah Fowler — His Qualifications — Preston Valley — A Cast of the Drag — Its Produce — Osmington — Burning Cliff — Whitenose — A tragical Adventure — Examination of a Dredge-haul — Brittle-stars — Sunstar — Bird’s foot— Cribella — Beauty of Starfishes — Soldier-crab — Cloak Anemone — Spider-crabs — Sepiole — Its Beauty- Changes of Colour — Curious Mode of Burrowing — Accessory Uses of Organs — Discharge of Ink— Murderous Propensities.

40—73

Chapter IV

Excursion to Wyke — Advent of Summer — Rural Sights and Sounds — Cockchafers — Larks — Starling — Wake-robin — Germander Speedwell — Recollections — View of Weymouth Bay Fern “ Shells” — Belfield — Wood Plants — Clausilia — Magpies — Blackbirds — Cuckoo’s Note — Apologies — Wyke Church — The Fleet — Chesil Beach — Spotted Goby — Flatfish — Sand Launce — Strange Variety of Daisy Anemone — Its Parturition — Chesil — The Beach — Lobster fishing — Rocky Shore — Sea-weeds— The Long-tongued Medusa — Pearl-shells — Thorns turned to Gems — Belmont Ledges — The Goblet Lucernaria — Its Habits and Affinities. 74 — 95

Chapter V

Promenade on the Nothe — The Jetty — The Mixon — A fertile Garden of Algae — Tangles — Rhodosperms — Chlorosperms — Laver — The splendid Cystoseira — The Floods of Adversity — My own Tank — Disappointments — The Contents — Crowds of unexpected Guests — Results — The Black Goby — Its cannibal Propensities — Changes of Colour — Sucking Fin-disk — Mullet Fry — Their Manner of Feeding — Efforts to breathe Air — Wrasses — Their Beauty — Explanation of Frontispiece — The

CONTENTS.

XI.

Corkwing — The Green Wrasse — Habits of a Corkwing — Its tragical Fate — Pipefishes — The Two-spotted Sucker — Suggested Use of its Mechanism — Analogy of the Echeneis — Spawn of the Sucker — Double Vision — Examples of the Phenomenon— The Honeycomb Coral — Its Parasites — Its Structure— Its Populousness — Montgomery’s Coral- wTorms — Spiritual Analogies — The Heavenly Jerusalem. 96 — 126

Chapter VI

A Walk through Portland — Fortune’s Well — Old Smuggler — Bow and Arrow Castle — Church Hope — Vast Chasm — Resemblance to Lundy — Southwell — Keeve’s Hole — Awkward Accident— Natural Arches and Pillars — Sea-weeds — The Tansy — Its Nest — The Peacock’s Tail — Seaweed Gardens — The Strawberry Crab — Its climbing Propensities — Connexion between long Arms and climbing Habits — The Cloak Anemone— Its Singular Form explained — Unaccountable Companionships— Illustrative Examples of the Species — Efficiency of the Thread- capsules— The Rosy Filaments — The Parasitic Anemone — Its Size, Form and Colours — Its Associations — Its missile Weapons— Rank Odour. 127 — 150

Chapter VII

Another dredging Day — Fading Memories — A Calm — Durdle- Door — An Archway of Rock — A Walk under the Cliffs — Young Gulls — The Cow and Calf — Search for Sea- weeds — A Breeze — Zoea of Crab — Its Habits — Singular Capture of a Fish — Contents of the Dredges — The Sea-mouse — Its remarkable Splendours — Interesting Structure — Pennant’s Ebalia — Its Habits — Its Fate — Soldier-crabs — Resemblance to Spiders — Pugnacity — Curious Associations — Parasitic Anemone — Parasitic Worm — “ Snatch and Swallow” — A Crab “moving House” — Details of his Proceedings — Prawns — Their Elegance— Eye-gleams — Manner of eating — Cleanliness — A judicial Appointment — Its Mercy — Its Extension to the Creatures — Examples of Animal Cleanliness — The Prawn’s Scrubbing Brushes — Ser pulse — The Beauty of the Animals — Their Watchfulness — A curious Stopper — Locomotive Bristles — Comb-plates — Their Operation. 151 — 183

Xll.

CONTENTS.

CHAPTER yin.

A Drag on Smallmouth Sands — The Abergavenny — Chalk Figure of King George — Varieties of Ground — The Little Weever — Flat-fishes — The Thomback — The Painted Ray — The Bordered Ray — The Angel — The Gemmed Sea-slug — Forestbearing Crabs — Shrimps — Garret Windows — iEsop-prawns — Cranch’s iEsop — White’s iEsop — The Scarlet-lined JEsop — The Plumose Anemone — Its Beauty and Size — Variation in Colour — The Disk — Its Sociality — Its Locomotion — Runcina • — The Fiddler Crab — His natatory Powers — A “ striking” Species — His grim Habits — Ferocity — Indiscriminate Greediness— Tit for Tat — An odd Fish — Use of the Lamm — A Fisherman’s Rubbish” — Plate Armour — A fine Beard — Its probable Use — The Nothe Ledges — Various Sea -weeds — Phyllophora — Codium — Griffithsia — Rivularia. 184—203

Chapter IX

A Meditation — The Spiritual Use of Natural History — Extremes of Opinion — Scriptural Warrant for the Study — Its Limits — Three inspired Modes of Treatment — I. Direct Testimony to God — Founded on our Ignorance — On our Knowledge — Various Attributes of God discoverable — Responsibilities— Cain’s Offering — II. Moral Lessons by Examples — III. Spiritual Parallelisms — Similes — Types —Symbols — Allegories — God’s Message of Grace. 204 — 215

Chapter X

Autumnal Gales — Lucernaria — Mode of finding it — Analogy with Medusa — Description — Habit of Bell Lucernaria— Last Look at Weymouth — London Studies — The Spinous Cockles — Their gymnastic Feats — Fine Appearance of the Foot — Openheartedness— The Siphons and their Use — Strange Creatures in the Sea — The Rough Syrinx — Value of a Bit of Stone — The Terebella — Ancient Masonry — Crawling and Swimming Feats — The Gold- comb — Its Tube — Its Combs — Their Use — Its Mode of Burrowing — Respiration — Structure of the Tail — The Gills — The Spears — Use of these Organs — Self-abolition — A Faculty of Echinoderms — Brittle-stars — Cross-fish—

CONTENTS.

Xlll.

Suicide of one — Holothurise — Chirodota — Its Structure — Its Manners — Ovarian Threads — Effusion of Colour — The Leaf- Worms — Their Elegance — Evolution of the Stomach — A new Species — Structure of the Spears — Use of these Organs not entirely known — Respiration — Reflections. 216 — 254

Chapter XI

Practical Instructions — The Name — Yivarium — Aqua-vivarium— Aquarium— The Tank — Form and Size — Aspect — Cost— The Preparation — Artificial Rocks, &c.— The Bottom — Water — The Stock— Plants — Animals — Procuring Specimens — Transmission— General Directions — Purification — Occasional Death — Instruments — Artificial Aeration — Evaporation — Cleansing the Sides —Conclusion. 255 — 278

LIST OF ILLUSTEATIONS.

PLATES.

I. The Ancient Wrasse . . . „ . .Frontispiece.

II. The Smooth Anemone, &c Page 38

III. Star-fishes 64

IV. The Parasitic Anemone, &c. 150

V. The Plumose Anemone, &c * 192

VI. The iEsop-prawn, &c 220

LIGNIGRAPHS.

I. Collecting under Byng Cliff 18

II. Foot-jaw of Broad-claw 48

III. Dredging off Whitenose 60

IV. Portland, from Belmont 76

V. Durdle-door 154

VI. The Fountain Aquarium 254

THE AQUABIUM.

Chapter I

April is come at last. The arctic frosts, dreadful and protracted as they were, of February and March, that chilled the very life out of my poor cherished Actinias, and left me mourning over empty vases, have at last passed away, and here are the sweet, soft, southwest breezes of April. And now farewell to grimy, smoky London, and down, down, to Dorsetshire, as swiftly as the panting engine can drag us.

What a change have twenty four hours made! We raise the blind from our bed-room window, and instead of a forest of chimneys in the distance, and a mews in the foreground, with grooms currying horses that won’t stand still, we gaze out upon the magnificent Bay of Weymouth, for our lodgings are on the ridge that they call the Lookout, with the sea below us breaking at the foot of the cliff.

The expanse before us has been described as second only to the beautiful Bay of Naples, by those who have seen both. I have not, and therefore cannot vouch

B

PORTLAND BREAKWATER.

for the justice of the comparison, hut certainly this is a glorious prospect. It is a lovely morning; the sun has not long been up, hut his effulgence fills the sky with splendour immediately in front, a splendour which trails along the intervening sea, as if it were the fiery monarch’s train.* Away on the left stretch the bold promontories and abrupt cliffs of Purbeck, twenty miles of purple coast, gradually lessening in apparent height and in distinctness of outline, until the bluff precipice that terminates the line, St. Aldhelm’s Head, is lost in the brightness of the eastern horizon. Then [the broad expanse of boundless sea brings the eye to Portland on the right, a lofty rounded mass, thrown out into strong light by the opposite sunbeams, and to that noble work the Breakwater, as noble in design and object, as marvellous in execution, which perpetually creeps out into the domain of the sea, presenting an effectual though scarcely visible wall to the waves, until by and by it shall stretch halfway across our present field of view, and inclose a safe harbour of refuge, on which many a mariner will bestow his grateful blessing. At such a time as this sweet April morning, indeed, a work like this may seem of little value, when the waves of the ocean only just suffice to break its face into gems of changing brilliance, and to make whispering music; while vessels of all sizes, like those whose clustering masts we see yonder under the promontory, ride with perfect security in the open road. But in the fierce gales of

Where like an Angel’s train

THE MARINE AQUARIUM.

November or March, when the shrieking blasts drive furiously up the Channel, and the huge mountain - billows, green and white, open threatening graves on every side, how welcome would be a safe harbour, easy of access, and placed at a part of the coast, which else would be unsheltered for many leagues on either side ! Blessed be God for the gift of his beloved Son, the only Harbour of Refuge for poor tempesttossed sinners ! We may think lightly of it now, but in the coming day of gloom and wrath, when “ the rain descends, and the floods come, and the winds blow,” they only will escape who are sheltered there !

This visit to Weymouth was immediately connected with the Marine Aquarium. Those of my readers who have honoured my 'Rambles on the Devonshire Coast’ with their perusal, may remember the experiments I have there recorded, on the making of such an invention practicable in London, and other inland towns, and my anticipations of success. Early in December, 1852, I put myself into communication with the Secretary of the Zoological Society, and the result was the transfer of a small collection of Zoophytes and Annelides, which I had brought up from Ilfracombe, and which I had kept for two months in vases in London, — to one of the tanks in the new Fish House just erected in the Society’s Gardens in the Regent’s Park. This little collection thus became the nucleus and the commencement of the Marine Aquarium afterwards exhibited there.

It was in consequence of an engagement to supply

THE ACTION OF LIGHT UPON PLANTS.

with marine inhabitants the other tanks which the Zoological Society proposed to devote to this object that I proceeded again to the coast. The prosecution of that employment during the months of May, June, and July, in the course of which upwards of five thousand specimens of animals and plants passed through my hands, made me acquainted with many curious facts in their economy and habits, and with many interesting traits in their history, which are not recorded (so far as I am aware) in works of science.

The facilities for observation thus afforded me have been augmented by means of Aquaria of various forms and sizes, which I have had made for my own private use, and of which I shall have occasion to speak in the following pages. In them I could mark with leisure and precision the manners of the creatures that were living at home , yet constantly under my eye.

Considering the novelty and curiosity of the exhibition thus offered to the public, and the popularity which it achieved, it may not he uninteresting to treat of a few of the more prominent objects in detail, and of the modes in which they were collected. We generally feel an interest in knowing somewhat of the antecedents of any person or thing that strongly attracts our attention ; and in the present case more than idle curiosity may be gratified, since the record of my experiences may he useful to others in forming similar collections, either for public exhibition or for private study.

The idea of maintaining the balance between animal and vegetable life on chemical principles is not quite

THE ACTION OF LIGHT UPON PLANTS. 5

so novel as I had at first supposed. Priestley first advanced the opinion that plants in certain circumstances emitted oxygen gas; and Ingenhousz soon after discovered that the leaves of plants, when immersed in water, and exposed to the light of day, produced an air, which he announced as oxygen gas. This result, however, was doubted by Ellis, in his elaborate treatise on Atmospheric Air, and, as he considered* disproved.* The consumption of oxygen by animals in respiration, and the emission of carbonic acid from the lungs and skin, were well shown by this writer, who maintained, however, that this latter gas was also emitted by the leaves of plants.f

At the third Meeting of the British Association, held at Cambridge in 1833, Professor Daubeny communicated a notice of certain researches which he was then pursuing, concerning the action of light upon plants, and that of plants upon the atmosphere. “He considered that he had established, by experiments on plants immersed, sometimes in ivater impregnated with carbonic acid gas, and at others in atmospheric air containing a notable proportion of the same, that the action of light in promoting the discharge of certain of their functions, and especially that of the decomposition of carbonic acid, is dependent neither upon the heating, nor yet upon the chemical energy of the several rays, but upon their illuminating power.

“He regarded light as operating upon the green parts of plants as a specific stimulus, calling into action, and keeping alive those functions, from which

Inquiry <fcc. p. 57 — 60.

THE ACTION OF LIGHT UPON PLANTS.

the assimilation of carbon and the evolution of oxygen result. ....

“He had satisfied himself that in fine weather a plant consisting chiefly of leaves and stem will, if confined in the same portion of air night and day, and duly supplied with carbonic acid during the sunshine, go on adding to the proportion of oxygen present, so long as it continues healthy, at least up to a certain point

“ Considering the quantity of oxygen generated by a very small portion of a tree or shrub introduced, he saw no reasons to doubt that the influence of the vegetable might serve as a complete compensation for that of the animal kingdom .”

In 1837, Mr. Ward made a Report to the British Association, “ On the growth of Plants in closed Cases,” at the end of which he “ directed the attention of the members to vthe development of animal life upon the same principles.” He was “ quite certain that a great number of animals would live and thrive under this treatment.”

In his treatise on the same subject, published in 1842, he dilates a little on this matter, chiefly with regard to increasing the purity of air for breathing in large towns, as a remedy for disease. “The difficulty to be overcome,” he observes, “ would be the removal or neutralization of the carbonic acid given out by animals; but this in the present state of science could easily be effected, either by ventilators or by the growth of plants in counexion with the air of the room, so that the animal and vegetable respirations might counterbalance each other. The volume of the

DR. JOHNSTON’S EXPERIMENT.

air, with the quantity of vegetable matter required, as compared with the size and rank in creation of the animal, would he a problem well worthy of solution.”*

In the same year (1842) Dr. Johnston published his “ History of British Sponges and Lithophytes,” in which, arguing out the vegetability of the latter, he mentioned in a note what is the most germane of all to our purpose, — the actual formation of a little Marine Aquarium. To Dr. Johnston therefore, as I think, must he assigned the honour of the first accomplishment of this object. His words are as follows : —

“ Was there a need of adding any additional proof of the vegetability of the Corallines, an experiment now before me would seem to supply it. It is now eight weeks ago since I placed in a small glass jar, containing about six ounces of pure sea-water a tuft of the living Corallina officinalis, to which were attached two or three minute Conferva , and the very young frond of a green Ulva ; while numerous JRissoa, several little Mussels and Annelides, and a Star-fish were crawling amid the branches. The jar was placed on a table, and was seldom disturbed, though occasionally looked at; and at the end of four weeks, the water was found to he still pure, the Mollusca and other animals all alive and active, the confervae had grown perceptibly, and the coralline itself had thrown out some new shoots, and several additional articulations. Eight weeks have now elapsed since the experiment was begun, — the water has remained unchanged,

* On the Growth of Plants, p. 70.

MR. WARINGTON’S

— yet the coralline is growing, and apparently has lost none of its vitality; but the animals have sensibly decreased in numbers, though many of them continue to be active, and shew no dislike to their situation. What can he more conclusive ? I need not say that if any animal, or even a sponge, had been so confined, the water would long before this time have been deprived of its oxygen, would have become corrupt and ammoniacal, and poisonous to the life of every living thing.”*

On the 4th of March, 1850, at a Meeting of the Chemical Society, Mr. Robert Warington communicated the results of an experiment which he had been prosecuting for nearly a year, “ On the adjustment of the relations between the animal and vegetable kingdoms, by which the vital functions of both are permanently maintained.” Two small gold fish were placed in a glass receiver of about twelve gallons’ capacity, covered with thin muslin to exclude dust and soot. The vessel was half filled with spring-water, with a bottom of sand and mud, and some loose fragments of limestone and sandstone, so arranged as to afford shelter and shade. A small specimen of Valisneria spiralis was at the same time planted in the mud, and kept in place by a stone. The whole was then left undisturbed.

Every thing went on well for a time, till it was found that the natural decay of the older leaves of the plant began to produce turbidity in the water, and a confervoid growth accumulated on the sides of the

MARINE AQUARIUM.

vessel, and on the surface of the water. To meet this emergency, Mr. Warington introduced a few common Pond- snails f Limnea J} which greedily fed on the decaying vegetable matter and slimy mucous growth, so as quickly to restore the whole to a healthy state.

The result was now quite satisfactory. The plant throve and increased greatly by offshoots and suckers ; the fishes continued to preserve their health and beauty, while the snails deposited enormous masses of eggs, thus supplying food for the fishes, as well as performing the office of scavengers.

Thus the success of the experiment was established, and an Aquarium was formed in fresh water; which has continued to prosper to the present time ; the animals and plants maintaining each other in healthy life, and the water preserving its purity unchanged.

In January, 1852, Mr. Warington began to prosecute experiments of the same kind with sea-water, which presented some difficulties arising from the compound nature of that fluid, and from the peculiarities of marine vegetation. These difficulties, however, yielded to the perseverance and skill of the operator, and while I write these lines I am a personal witness to his complete success, having just seen (January 1854) specimens of Sea-anemones and other marine animals in good health in that gentleman’s Aquarium, which I know were sent from the sea-side more than a year and a quarter ago.

A Memoir by Mr. Warington, which appeared in the “ Annals of Natural History” for November, 1853, gives some very interesting details of the progress of

MR. WARINGTON’S the marine experiments ; and from it I shall make a few extracts.

“ The sea-water with which the experiments were conducted, was obtained through the medium of one of the oyster-boats at the Billingsgate fish-market, and was taken from the middle of the English Channel.

“ My first object was to ascertain the kind of seaweed best fitted, under ordinary circumstances, for keeping the water clear and sweet, and in a sufficiently oxygenated state to sustain animal life. And here opinions were at variance, for one naturalist friend whom I consulted, advised me to employ the Bhodosperms ; another stated that it was impossible to make the red weeds answer the purpose, as he had tried them, and strongly recommended the olive or browncoloured Algse; while, again, others thought that I should he more successful with those which had in theory first suggested themselves to my own mind, namely the Chlorosperms. After making numerous unsuccessful experiments with both the brown and the red varieties of Algae, I was fully convinced that the green weeds were the best adapted for the purpose.

“ This point having been practically ascertained, and some good pieces of the Enter omorpha and Ulva latissima in a healthy state, attached to nodules of flint or chalk, having been procured from the shore near Broadstairs, several living animal subjects were introduced, together with the periwinkle. Everthing progressed satisfactorily, and these all continued in a healthy and lively condition.

“My first trials were conducted in one of the

MARINE AQUARIUM.

small tanks which had been used for fresh water ; but as it was necessary, during the unsuccessful experiments with the brown and red sea-weeds, to agitate and aerate the water, which had been rendered foul from the quantity of mucus or gelatinous matter generated during the decay of their fronds, until the whole had become oxydized, and the water rendered clear and fitted for another experiment, it was, therefore, for greater convenience, removed into a shallow earthen pan, and covered with a large glass shade to protect the surface of the water, as much as possible, from the dust and soot of the London atmosphere, and at the same time impede the evaporation. In this vessel then I had succeeded perfectly in keeping a large number of beautiful living specimens in a healthy condition up to the close of 1852. I therefore gave instructions for the making of a small tank as a more permanent reservoir, and one more adapted for carrying on my observations and investigations on the ceeonomy and habits of the inhabitants.

“ From the experience I had obtained in my experiments with the fresh-water tank, I was induced to modify slightly the construction of this vessel ; thus, at the back, or part towards the light, the framing was filled with slate in the same way as the ends and bottom ; for I had found that the glass, originally employed, very soon became covered with a confer - void growth which had an unpleasing appearance to the eye, and in consequence of which I had been obliged to paint the glass on the exterior to prevent this growth from increasing to too great an extent, It was also an unnatural mode of illumination, as all

MR. WARINGTONS SUCCESS.

the light should pass through the surface of the water. The front towards the room and the observer was constructed of plate glass, the whole being set in a stout framework of zinc, and cemented with what is known under the name of Scott’s cement, and which I have found to answer for the purpose most admirably. Within this tank were arranged several large pieces of rock-work, thrown into an arched form, and other fragments were cemented in places against the slate at the hack and ends, and at parts along the waterline, so that the creatures could hide themselves at pleasure; a short beach of pebbles was also constructed in order that shallow water could he resorted to if desired. The whole tank was covered with a light glass shade to keep out the dust, and retard evaporation.