STEAM NAVIGATION TO INDIA.

Sir,-Your correspondent "H," seems inclined to pick a quarrel with me for venturing to differ in opinion from him, and recording my dissent to his views in your valuable miscellany. His last letter produces no change in my opinions, nor does it explain away any one of the facts to which reference was made in my former letters.

I am still decidedly of opinion, that the supineness of our East India Government is affording the Dutch and other nations an opportunity of acquiring a superiority over us, by means of an extensive line of steam navigation in the Indian Archipelago, and that the "steam flotilla" in the service of the company, if not altogether contemptible, is yet quite inadequate to the wants of that part of the British Empire. Hitherto the earnest remonstrances of the mercantile residents, and the strenuous exertions of the East India Steam Committee in England, have failed to produce their proper effect. Individual enterprize has been paralized by an influence which may not be described, and the general good sacrificed to a narrow and mistaken policy.

I am not aware that in any part of my correspondence upon the subject of East India steam navigation, that any statement has appeared to countenance "H.'s" misrepresentations of my sentiments, relative to the exertions now making by the Dutch, to establish steam navigation in India for commercial purposes, nor the flourish about the English being "about to reinforce the steam flotilla which they have long ago (sic orig.) introduced in the East Indies from home, by a number of steamers built and equipped in the country itself." Will "H." condescend to inform your readers of the names of those steamers "long ago" introduced into the East Indies from this country? The Enterprize was sent out from this country about twelve years since. What others are there sent out from this country "long ago?" The Atalanta, Berenice, and Semiramis, were sent out last year. The Hugh Lindsay was built in India. If the "steam flotilla" goes on increasing at this rate of five in twelve years, it will be many before it is equal to the increasing wants of India; and will afford, in reality, an opportunity to our Dutch neighbours to

monopolize the steam navigation of the Indian Archipelago.

But "H." charges me with veering round as to the speed of steam-vessels. If he had read my remarks with ordinary attention, such a charge would not have been made by him. In page 98 my statement was, that I had "not at present met with any steam-vessel (meaning, of course, sea-going steam-vessels, of which I was then speaking,) in the course of my somewhat extensive observation, that had been able to maintain such an average speed (10 miles) for several consecutive days."

"Some few boats will maintain 10 miles an hour for 30 or 40, or even 80 hours."

Now I still maintain this to be the fact. The Berenice is said to have attained the speed of 14 miles per hour when tried in Scotland, but what was her actual performance when on her passage to India? not ten miles an hour, nor any thing like it. If "H." will refer to the logs of the two vessels as given in the Nautical Magazine, he will find that he is mistaken as to the speed of sea-going steamers, even of the first class; and it must be obvious that he has misrepresented my meaning.

Whilst I am writing this, I have been informed that the Great Western arrived at Bristol on the 7th, having left New York on the 25th ult. This, indeed, would show a speed of rather more than 10 miles an hour; but it is to be remembered that this speed is acquired by a vessel of a very much larger class than any of those formerly afloat, and is in perfect consistency with my remarks in former letters, that with larger ships a greater velocity would be attained.

The Dutch are doing what the East India Government have been openly or covertly opposing-endeavouring to introduce steam navigation for commercial purposes into the East Indies.

The reference to the experimental steamer to be built at Bombay, confirms my previous remarks. Strong repre

sentations have been sent home of the necessity for immediately placing a greatly increased number of steamers on this service, and the greatest anxiety is evinced for the accomplishment of the object. The company have at length given orders that the experiment should be tried of building a steam-ship at Bom

bay." Now mark, Mr. Editor, it is not said that she is building, but that "the company have at length given orders" that she should be built at Bombay. Are these reluctant orders gone out? Are they couched in such terms that the executive government will understand that they are to be complied with? Or are they like some other orders of the honourable court only meant to be disregarded? In 1834 a Committee of the House of Commons passed some strong resolutions on the subject, and recommended that a steam communication should be attempted. Private individuals attempted to establish one, but were prevented carrying their intentions into effect, by the same power that determined Indian idolatry should be supported at the expense of government, notwithstanding their orders to the con

trary.

"H." speaks of " Indian and Arabian ports," having "been often visited by other steamers than those belonging to the company;" will he be kind enough to enumerate them, with the date of their risit?

The reference of "H." to my letter, page 150, is so obviously incorrect, that it exposes him to the suspicion of disingenuousness; for had he read the paragraph with ordinary attention, he must have perceived that the pronoun "he" was an error of the press, and should have been we," as is clearly seen by the concluding part of the sentence, which is " and that we (myself and others) should have been impressed with the belief that steam navigation was still in its infancy in that part of the British Empire, &c." Against whom does the charge of disingenuousness lie? Your impartial readers will acquit me of it.

The sneer about my advice being "good in itself" comes with an ill grace from "H.," as in my first communication I had referred to the fact, that the British residents in India were long since awakened to the importance of the object which they had been prevented from attaining, although actively seconded by Captain Grindlay and a committee in England. And here, Sir, I trust you will pardon my expressing the sense which I entertain of the valuable services which Captain Grindlay has rendered to the cause of East Indian steam navigation. He has ventured to advocate it, when in high quarters it was deemed an Utopian

scheme, and its advocates but little removed from insanity. Messrs. Seaward, in 1824, struck out a plan and demonstrated its practicability, but they met with but little attention-they were too much in advance of the age; and had Dr. Lardner then appeared in the field as the presiding genius of steam navigation, Messrs. Seaward would have been crushed beneath the unmerciful load of wet blankets which he would have applied to cure them of their insanity.

The excellent letter of "Piston" confirms my statements relative to the speed of some of the river boats, but does not apply to sea-going vessels. "Piston" states, that some steamers, which he names, did reach the speed of 131, 131, and 13 miles per hour, when tried under favourable circumstances (without passengers, or more than a moderate supply of coals on board, mind); from this "H." ventures to assert, that they have reached the astonishing speed of 20 miles per hour.

Whatever "H." may think of my concession, as he terms it, that an average of 10 miles an hour might be maintained during a steam voyage round the Cape, I confess there does not appear any inconsistency; for on reference to my letter, page 98, it will be seen that I was then speaking of existing steam vessels, and remarked that improvements were still required. My opinion expressed, June 9th, is quite consistent with this, as "H." must know, if at all conversant with nautical affairs; for in two vessels of the same form and proportions, the larger is always found to be the faster of the two.

If "H." will refer to his own letter, page 122, he will see the propriety of sparing any further regret about my disingenuousness. He there uses such a form of expression that would even now impress me with the belief that he did intend to convey his disapprobation of Mr. Hall's Patent Condensers; however, as he denies any intention of doing so, I must believe him, though he now admits that "the ill-timed advertisements of that gentleman (Mr. Hall) might have justified" him "in doing so, if no allowances were to be made for the rashness of an inventor in the full confidence of success."

It appears from a recent parliamentary return, that there are about 600 steamvessels belonging to the British empire,

Of

exclusive of government vessels. these 600, there are only 39 in all the colonies and possessions, which contain an aggregate population six or seven times larger than the mother country. Is the monstrous flotilla of five steam vessels in the East Indies at all commensurate with the wants of the population, or proportioned to the importance of that part of our dominions?

Since my first letter referring to the want of steamers in the East Indies, and the tardy stinted compliance with the reasonable claims of the British residents there, upon the merchant-princes in Leadenhall-street, I am informed, that two other steam. vessels have been contracted for, to be built in England, which will probably arrive out at the end of 1839, or during the early part of 1840, and add to our numerous and efficient steam flotilla already existing in the East Indies.

As an illustration of the greater velocity acquired by large vessels over smaller ones of the same form and proportions, I will just mention, that by advice from the British Queen off Falmouth, she was going through the water at the rate of eight knots, with a light breeze. This circumstance justifies the general expectation that she will prove a very fast vessel when steaming, if her machinery be properly adapted for her, and is equal to its reputed power.

Apologizing for having trespassed so much with a subject which cannot but interest your readers, I take leave of the controversy, and subscribe myself, Your obedient servant,

July 10, 1838.

GEORGE BAYLEY.

STEAM-BOILER EXPLOSIONS--THEORY

AND PRACTICE.

Sir,-Your correspondent "Scrutator" has assigned a probable, and certainly most efficient, cause for the bursting of the Victoria's boiler, or more properly the collapse of the internal flue,-the manner in which similar boilers, containing high steam, nine times out of ten, explode.

The steam-room in cylindrical boilers with a large flue is, proportionally to the water space, much less than in rectangular boilers, -a defect which must be met, either by an increased steam-chest or pipe, or by keeping the steam higher in

the boiler, and throttling it down into the cylinder. My object, however, is to point out, that the connection of scientific and practical knowledge is alone of value.

The practical man will blunder on till he is right at last, if he has common sense and sufficient funds. Theorists are equally subject to blunders, to the great delight of the practicists-parties, by the bye, who are often alone in possession of correct data, and who, by experience derived from observation, are enabled to guess at, rather than to exhibit reasoning for probable results, under different conditions-theorists, in fact, without a language to express their ideas. This, and the limits of power and correction, under different conditions, so as to lead to the highest possible results by the shortest path, are the legitimate objects of theory. Another class are sometimes called theorists in contempt,-persons not more remarkable for their reckless assertions without proof, than the absence of both practical and scientific knowledge." Scrutator" very properly objects to "if's" and "but's,"-conditions, in fact, not clearly expressed-loopholes for erroneous opinions, and gives an example of their misuse in his own letter:-" This boiler would do well at sea, if external condensation was adopted." What has the boiler to do with the means employed by the engineer to produce an assigned vacuum, as long as that assigned vacuum is produced?* The boiler has only to perform its allotted task. If the meaning is that a better condensation is afforded, as its advocates assert, by external condensation-for instance, to the extent of one inch of mercury, then it amounts to an admission of inferiority, to be estimated on the principles of heat required to evaporate water at about 16 and 163 lbs. pressure respectively, into steam, as used in the cylinder.

Theoretical, like practical, opinions are sometimes at variance, and in such cases one at least of the theoretical opinions will be oftener traced to false, or

We are surprised that our correspondent, who appears to understand his subject upon other points, should put such a question. The advantage of external condensation alluded to by "Scrutator" had no reference to the production of a vacuum, but to the condensing of the steam and the returning it in the form of pure water to the boiler, whereby tubes or small chambers may be used without their being liable to be choked up by the incrustations of saline or other deposits incident to the use of sea water, -ED. M. M.

the omission of important, data, than to incorrect reasoning.

Success and failure were both theoretically predicted of the direct unknown voyage of the Great Western to New York, from arguments founded on known voyages performed; the failing theory has attracted most attention, like a bad hole in blasting rocks-much noise and no work. The successful theory is remarkably well expressed in a report to the committee at Bristol, dated January 1st, 1836, and signed Christopher Claxton, managing director, which silently effected its purpose. The pleasure I felt on reading this report, as given in the Nautical Magazine in January, 1837, was only equalled by a comparison of the estimated, with the actual results, of the first voyage.

Previous to the opening of the Manchester and Liverpool railway, theory arguing from known performances, foretold that a speed greater than ten or twelve miles per hour would be impracticable, and quite forgot a possible condition— increased evaporation in the same space, without any great increase of boilerweight. The method of forming numerous flues of small tubes-the reverse of the common steam-coach boiler-seems to have been suggested by the treasurer -evidently a theorist respecting heatto the engineer, whose adoption of the plan is as creditable as the suggestion, and who fairly earned the competition and renown.

Theory, at least, did good service here, but sooner or later it would have been effected by some person, who might have had pretensions to have been dignified with the more coveted title of being a practical man.

If any difficulty was ever found to occur in not getting the lower tube to draw as much air as the upper, theory would suggest that a proportionate contraction of the upper flues at either end would effect this object. Practice might find out some objection relative to a soot deposit. I have alluded to this merely to show the connection between theory and practice without any knowledge whether it has ever been done, or required to

have been done.

The theory of fusible plugs, to melt at assigned temperatures, is very pretty, and was introduced with Trevethick's high-pressure boilers, and is still often used in the mining modification of these boilers. Recent experiments have shown

that on continued heat they melt at lower temperatures; but for this allowance can be made. It was lately mentioned to me that these plugs have been abandoned in steamers, where they will not do, especially in the weather flues, which are apt to get hot when the vessel heels. This is a specimen of a practical argument from a defect, not of the plug, but of the boiler: they must meet the real objections how they can-fixing difficulties, and liability of failure on a lee shore.

For smooth water craft, partitions in a single boiler, with a separate feed-pipe to each division, will obviate the first objection; but the large boiler top is exceedingly objectionable to passengers, as on explosion the whole flies off together. It is their interest to have separate boilers-then the flues become the weakest parts, and the enginemen must keep a bright look-out for themselves, as the only persons likely to suffer on an explosion. Partitions are not sufficient in sea-going vessels to prevent, under some circumstances, the effect of the constant flush of the water to leeward. Three or four separate boilers alone will enable the weather-boiler to be forced, and the sea one eased, by which means a great increase of stability is afforded-a point of as much importance in crank steamers as trimming to windward in crank pleasure-boats.

Theory, judging from the disposition to obtain power in a small space, and the eventual tendency of expansion, at present only used with low steam, may safely predict the rapid approach of a most dangerous era in steam navigation, -the transition period from low to higher steam. Competition will induce the attempt, and (whether successful or not) considerable danger will exist, until the safety conditions are fully ascertained. As for the United States, they seem simply distinguished, in the inland waters especially, by an engineering recklessness, in utter defiance of theory and practice.

Legal enactments are likely to prove futile. Two points alone perhaps would prove efficient,-increase of knowledge among the enginemen, which time only can effect, and a deodand on the vessel for each death of 1007., to be doubled on neglect being proved, so as to render an explosion an expensive operation for the

owners.

I remain, Sir, yours respectfully,

N. S.