on the land side, not being very perpendicular, are covered in many places with vegetation, and offer a more pleasing outline to the eye than the precipitous cliffs usually seen on this part of the coast. The most beautiful and wooded part of the under-cliff is that towards Dovor, and to this we will pay the most attention, for we shall find more to attract us here; and if we ramble towards Folkstone we shall be straying too far from home.

To the right of the path which leads down the cliff, on some bushy slopes near the bottom of the descent, we shall find large beds of strongscented Lettuce (Lactuca virosa), an useful medicinal plant, but little prepossessing in appearance or odour, the latter being very rank and unpleasant. A thick white juice exudes from any wounded part of the plant, which is very troublesome to those who handle it; it soils cloth very much, and the stain is difficult to remove, as I know from experience. Continuing to the left towards the beach, we shall come to a little stream, running out from beneath a bed of clematis and brambles, close to the sea-shore, where it loses itself among the shingle. Brookweed or Water Pimpernel (Samolus Valerandi), grows near this spot, in damp places; and on the sloping banks on the Folkstone side, we shall observe wild Madder (Rubia peregrina), growing in abundance, and pyramidal Orchis (Orchis pyramidalis). A little further on in the same direction, high up, on a chalk slope, there is quite a bed of smooth Seaheath (Frankenia lævis), which is well worth visiting, to observe this plant growing in luxuriance.

In my first ramble I gave localities for the wild Madder and smooth Sea-heath; but as both plants are rare, I have mentioned them here again, as they seem to grow more luxuriantly, and be more abundant than on the other side of Dovor.

On and about the sea-shore common Hound's-tongue (Cynoglossum officinale), is to be met with in many places, and the common wild Parsnep is most abundant in this under-cliff, growing in large beds, to the no small satisfaction of myriads of insects, which enjoy the flowers when open.

The reader will find by referring to G. E. Smith's Catalogue of the Plants of South Kent, that several of the Orchis tribe, and other rare plants, are to be found in East-Wear Bay, and at Lydden-spout; but they were all passed when I had the pleasure of visiting this interesting locality.

We will return from the under-cliff by the same way we entered; and when again on the high ground, we will turn our faces towards Dovor, and make our way to Shakspeare's Cliff. In the corn-fields about here, the wild Oat (Avena fatua), abounds, and grows to a very large size. It is a tall and handsome grass, holding its head with pride over the corn it grows amongst. One culm which I gathered was more than five feet high, and the thickest part of it was upwards of a quarter of an inch in diameter. We all associate the idea of Samphire with Shakspeare's Cliff, from the celebrated lines in King Lear. The plant still grows there in profusion, and the samphire-gatherer carries on his adventurous trade of culling the plant from the surface of the cliff, letting himself down by a rope, which passes over a post, holding one

end in his hands, and having the other tied round his waist. As we descend from the summit of this cliff, on the Dovor side, we shall observe Dyers' Green-weed (Genista tinctoria) growing; and near the bottom of the descent, in the hedges and on the slopes near the beach, we shall find common Alexanders (Smyrnium olusatrum.)

Our rambles in the immediate vicinity of Dovor will conclude here; but I shall, at a future opportunity, request the reader to accompany me in another ramble to Sandwich, where I think we shall find a very ample remuneration for our trouble. Wishing, however, to give as much information as I can on the localities of the plants growing near Dovor, a friend, who collected there this spring, has kindly penned the following observations for me. Most of the specimens I have examined, to ascertain their accuracy, and I think the localities may be depended on.

Marsh Speedwell (Veronica scutellata), moist places, East-Wear Bay; wild English Clary, or Sage (Salvia verbenaca), under Shakspeare's Cliff; opposite-leaved Pond-weed (Potamogeton densus,) water in the lane, near Charlton, parallel with the London-road; Corn Gromwell (Lithospermum arvense), close to the London-road, beyond Ewell; common Henbane (Hyoscyamus niger,) among the shingles on the edge of the walk, along the Marine Parade, on the rope-walk, near Shakspeare's Cliff, and again by the Martello towers at Folkstone; Hairy Violet (Viola hirta,) lanes near Guston; common Herb-Paris (Paris quadrifolia,) in a shady lane, about half a mile from the entrance to Lord Guildford's park, on the Dovor side; also abundantly where the wood has been cut down in the same neighbourhood; tuberous Moschatell (Adoxa moschatellina), shady lane, just opposite Kearsney Abbey, near River; Sea Campion (Silene maritima), frequent on the coast; common Columbine (Aquilegia vulgaris,) on the confines of a retired wood, about half a mile from the west side of the London-road, beyond Ewell, near Lydden; common Bugle, white variety, lane near Church Hogham; yellow Weasel-snout (Galeobdolon luteum), in shady lanes, near Lord Guildford's Park, also in those beyond River; Hairy Rock-cress (Arabis hirsuta), on the sloping banks as you ascend to the castle; tuberous Orobus (Orobus tuberosus), on the banks of a field, about a mile beyond Kearsney Abbey; Spring Vetch (Vicia lathyroides,) dry banks on the London-road, and close to the sea-shore at Folkstone; Green-winged Meadow Orchis (Orchis Morio), in the meadow above the cliff, about half a mile before you reach Folkstone; early purple Orchis (Orchis mascula), in the woods and hedges in every direction, particularly fine in the woods at Waldershare; great brownwinged Orchis (Orchis fusca), on a steep chalky hill, leading from Lydden to Waldershare; Spider Ophrys (Ophrys aranifera), abundant in East-Wear Bay, on the under-cliff and close to the shingles.

W. W. S.

VOL. II.

I

8

114

PREVENTION OF EXPLOSION IN STEAM-BOILERS.

ANALYSIS AND CURSORY EXAMINATION OF A REPORT, MADE IN CONSEQUENCE OF AN INQUIRY INTO THE CAUSES AND MEANS OF PREVENTION OF THE EXPLOSIONS OF STEAM-BOILERS; RECENTLY TRANSMITTED TO THE GOVERNMENT OF THE UNITED STATES, BY THE FRANKLIN INSTITUTE OF PENNSYLVANIA.

PUBLIC attention, in the United States, having been roused in the most painful manner, to the disastrous consequences of the frequent explosions of engine-boilers on board steam-boats in that country, the managers of the Franklin Institute of Pennsylvania determined upon an inquiry into the causes of these dreadful events. Such a philanthropic determination was in perfect harmony with the spirit and conduct of the great man, whose name they have adopted as a distinctive appellation; and if they have not hitherto perfectly succeeded in developing every point of this intricate inquiry, they have the distinguished honour of being the first public or private body which has attempted an examination of the subject, by experiments and apparatus on a large scale, designed on purpose to bring the more important current opinions and theories to the test of actual proof. We think that even their omissions, failures, and mistakes, may be of benefit; they may excite further examination, provoke discussion, and tempt new trains of investigation. The disagreement also of their results, with those of some eminent European experimentalists who have preceded them, will impose the duty of a re-examination upon the latter, in those instances, at least, to which the members of the Franklin Institute seem, on their part, to have bestowed the most scrupulous attention.

In a country which, from its hydrographical advantages, is so deeply interested in the extension and prosperity of steam-navigation, it was remarkable, that an inquiry of this importance, rendered imperiously necessary by the repeated destruction of life and property all over the Union, should have been delayed so long. The general government certainly ought to have instituted, much earlier, a minute examination into all the causes of these murderous accidents, and immediately prevented their recurrence, as far as police-regulations could have been effective. They ought then to have gone further, and obtained a carte blanche upon the treasury, to enable them to invite the assistance of the most eminent scientific and practical men, European as well as American, and to direct them to examine the evil in every form, and never to relax their labours until they had discovered such specific means of prevention as would render the most colossal steam-generator as innocuous as a tea-urn. They should not have permitted a self-sustained society to drain its little exchequer, and to call upon a few able men among its members, to devote their leisure hours or sacrifice their professional ones, to undertake a work, which to be effective must necessarily be long, laborious, and costly; demanding considerable scientific attainment, great practical skill, and unremitting attention.

It is not too much to say, that to have completely accomplished this object, would, in the present rapidly and widely-spreading extension of

steam-navigation, have been a benefit to the whole human race. It would certainly have conferred a reputation of disinterested pursuit of principle to the United States, which they have been reproached with neglecting, and which every admirer of their free institutions would wish them to enjoy. President Jackson and some of his fellow-citizens "down East," may be surprised when they hear it asserted, that the extinction of the national debt might have been honourably delayed a few days for such a noble

purpose.

We may be reminded that in an earlier part of this Magazine*, we cited the conduct of the United States' government in this very matter, as one deserving of honourable mention: we had then seen the introductory part only of the Report under consideration. We now see in the preface to this Report, (which the committee have, oddly enough, thought proper to append to it,) that it was not until after the resolution had been moved and passed by the managers of the Franklin Institute, and while their committee were engaged in the inquiries, that a letter was received from the secretary of the treasury, inviting experiments on the subject of explosions of steam-boilers, at the expense of the treasury department, the house of representatives having placed funds for this purpose at the disposal of the department. But "better late than never," and we believe the general government of the United States has yet the undisputed honour of being first (as a government) in this important examination. Who will be the second? We know who ought to be, and to whom it is a disgrace that they were not foremost to discuss and to attain this important desideratum,—we mean the British government. They cannot plead the fear of a want of funds, unexampled opportunities for actual observation and experiment are within their command,-and there is close at hand, to advise and to assist, the Institution of Civil Engineers of London, an association of men who, from their daily pursuits, their peculiar position, their varied intelligence, and their practical experience, would probably be superior for this purpose to any other body in existence.

We proceed to describe what was attempted by the Franklin Institute. On the 10th of June, 1830, the managers appointed a committee of seventeen members, "to examine into the causes of the explosions of the boilers used on board steam-boats, and to devise the most effectual means of preventing the accidents, or of diminishing the extent of their injurious effects.", The names of these seventeen gentlemen are given, but, (except in the case of four M.D.s,) their several professions, employments, or pursuits, and their qualifications for this particular purpose, are not mentioned. The only person whose scientific reputation has been sufficiently extensive to reach Europe, was lately in this country, and openly stated that he never attended a single experiment.

The committee, soon after their appointment, took a proper step to obtain the most valuable kind of information. They addressed a circular to such persons as they supposed were acquainted with the particulars of such explosions, as were up to that period undescribed; and though they published the knowledge they so obtained in the * Vol. I., p. 341.

+ Robert Hare, M.D., Professor of Chemistry in the University of Philadelphia,

Journal of the Franklin Institute, in the years 1831-32, it would have been gratifying to have found a general view of the facts in the introductory part of the Report.

The committee also drew up a series of questions, a plan of experiment based upon these questions, and an estimate of the cost of the experiments. None of these, however, are given in the Report, nor appended to it, omissions which are much to be regretted.

The secretary of the treasury, to whom the questions, plan, and estimate were submitted, approved them, and left the committee free to add any other subjects, or prosecute any other modes of inquiry which might suggest themselves, limiting, however, the sum to be expended. We are certainly curious to know what was the amount of the funds placed by the house of representatives at the disposal of the treasury, for such an object of national interest, and also to know the limit of expenditure prescribed by the secretary of the treasury. These sums, though several times spoken of, are never actually stated in dollars; and we confess we have our fears as to their being of an amount either adequate to the object, or worthy of a great nation. If these amounts should ever be given, perhaps the Franklin Institute will add that of their actual expenditure: it could not fail of being useful.

was

On the 1st of November, 1830, a sub-committee of seven appointed to conduct the experiments; these were Messrs. Bache, Reeves, Keating, Baldwin, Merrick, and Lukens. Subsequently the experiments which related to the strength of iron and copper used for steam-boilers, were separated from the others, and confided, on the 4th January, 1831, to a second sub-committee of three persons, viz., Messrs. Bache, Reeves, and Johnson: two of these, it will be observed, were also members of the first sub-committee.

At the end of five years from the date of their appointment, the first sub-committee made a report of their experimental investigations. This, after having been adopted by the general committee, was on the 23rd December, last, ordered by the manager of the Institute to be submitted to the secretary of the treasury, and it has since been published in five numbers of the journal of the society.

The second sub-committee have not, according to the latest accounts received, presented any report; nor have the general committee (as far as we know), made any communication to the public on the subject for which they were appointed, beyond what we have stated.

The omission which we have noticed, of the plan of experiments &c., has produced an apparent want of connexion throughout the report as published; and this, in addition to the occasional absence of perspicuity in the descriptions, and of important detail in the experiments, is extremely annoying and embarrassing to those who are anxious to understand and appreciate, not only that which has been done, but also (what is highly important) the means by which it was accomplished.

Great care and attention appear to have been bestowed upon the construction of the apparatus designed and used for the experiments. Many of the provisions against error, suggested by able experimenters in analogous cases, were known and adopted. There was, however, scarcely any novelty in the apparatus, nor in its application; probably