In what respects is the great experiment of 1852-3 a triumph ? in what respects is it a failure? Probably no ship has been constructed in modem times which has attracted more attention, and from the performance of which more decisive and important results have been expected, than from the caloric ship Ericsson.
The experiment has been as yet, strictly speaking, undecisive, but we consider it substantially a failure. The extraordinary anticipations of the mass, and the hopes or the fears of the mechanic, have been yet unrealized.
Many are deeply and pecuniarily interested in the question of its success or failure. Thousands of men are now living in easy and careless circumstances, supporting a family in a tolerably liberal and expensive style, whose whole capital is thorough and long experience in the manufacture and use of steam.
Thousands of others are relying for wealth on their established business, and their facilities for the manufacture of peculiar styles of engines, boilers, tubes, gages, valves, cocks, regulators, felting, hydrostats, salinoineters, condensers, refrigerators, and the various etceteras of steam-engineering. Other more enterprising men would hail any revolution as a god-send ; and the whole world are directly or indirectly interested in any device which shall perform the work of the steam-engine better or cheaper.
The caloric ship has now been several months in service ; has its performance established any facts ?
In the absence of favorable opportunities for information, we must continue, as heretofore, to approximate as near as may be to the actual condition and results of the experiment. The ship is now lying quietly at her dock in Williamsburg. The templates are shaped for the new heaters, or bottoms of the cylinders, and their construction is ready to be commenced on, should the proprietors of the ship deem it expedient to continue the experiment longer. Fickle public opinion seems somewhat wavering with regard to its merits.
A few daily and weekly papers (a tolerable index of the general sentiment of the community) have copied the letter of Capt. Ericsson, in our last number without comment, but the great majority maintain a profound and ominous silence. The stationary engine for the Evening Post establishment is nearly completed, having been already in operation, experimentally, in the shop.
This engine is composed of two single-acting engines, essentially similar in principle and fonn to those of the ship. The reservoir, however, encircles the furnace in such a manner as to economize the radiant heat which would otherwise escape. Of the progress of tho various caloric navigation companies which were, a few months since, reported as soliciting the legislatures of several States for acts of incorporation, we know nothing.
The above is probably correct, so far as it goes. Our query with regard to the blowing passages being open or closed on the trial trips has been answered since our last issue. The passages were closed.
The Ericsson has been two trips down the harbor and one to Washington, or vicinity. The forced draught was not used on these trips. " More than seven miles per hour" has been obtained by a consumption of four and a half tons of coal per twenty-four hours ; the average speed on the sea voyages, between New York and the Potomac, was, we think, from three to five miles per hour.
On leaving Alexandria on the 6th of March, in a dead calm, the engines of the caloric ship made as much as nine turns a minute, Acquia Creek, on the Potomac, being reached in four and a half hours, the forced draught passages having been previously closed with brick-work. The engines have performed regularly and smoothly in a heavy sea, and have shown themselves to have been sufficiently braced in the ship.
All this is claimed, and probably with justice, as among the results of the experiment, yet, aside from the practical difficulties in the details, which may, perhaps, yet be removed, the main object of the experiment remains unaccomplished. That object is to supply the place of the steam-engine in navigation.
Thus far it has proved itself open to its chief objections, with out its advantages. The steam apparatus is costly, heavy, cumbersome to manage and keep in repair, it occupies a large portion of valuable space in a vessel, and involves a great expense in consumption of fuel, &c.
The caloric engine is open to all these objections to a greater or less degree. Its first cost, or repairs, cannot yet be satisfactorily determined, this being the first, and a first machine of any kind always costing more than succeeding ones. Its weight has not been published, but, without doubt, is considerably more than that of the steam-engine, with boilers, water, &c, and the space occupied in the ship may be similarly estimated.
The space and weight we suppose to be several hundred per cent, greater than the usual marine steam apparatus of the same power.
In fuel there is experienced an economy, how great depends on how much coal is burned and how much power generated under all the usual varying circumstances. Capt. Ericsson objects to our proposed answer to his question on coal and speed, by elaborate calculations, and insists on a direct answer to the following question : Is there a steamship inexistence, of 40 feet beam and 18 feet draught of water, capable of running at a rate of 7 miles per hour on 9 tons of coal per day ?
We presume there is not ; nor is there a clipper ship which can be worked economically by a single sailor.
The fuel must be proportioned, in some degree to the engines. Perhaps the nearest approach to the dimensions of the Ericsson is the new steamer John L. Stevens, which is reported as now steaming 10 miles per hour on 12 tons per day.
|Length on deck||Breadth of beam||Depth of hold|
|J. L. Steven||285.5||40||27|
The average draught of the Stevens when loaded, we have not at hand, but any extraordinary excess in tho Ericsson argues great weight in her machinery. Assuming, according to the usual mode of computation, that the power required to propel a vessel is somewhat proportional to the cross section, angles of entrance and clearance, and cubes of the velocities, the power required to propel the two should be
indicating that 9 tons on the latter would give a greater speed than that claimed for the Ericsson, and making the relative economy of their engines compare as follows:
|J. L. Steven||12||100|
But granting a considerable economy of fuel, which there is certainly a fair prospect of obtaining in this engine, both the steam and caloric vessel must, in order to compete successfully with sailing-vessels, be swift and sure.
Their sharp hulls, if rigged with suitable spars and sails, would make good passages, the expensive mechanism is added to make them still fleeter. Has this single object been accomplished in the case of the ship in question?
The main object, the whole object for which the marine engine is employed, is - shall we say - defeated. At the rate with which the Ericsson made the passages from New York to Alexandria and return, the passage to Liverpool would be performed in from 25 to 50 days ; at the rate of 7 miles per hour, attained in smooth water under favorable circumstances, the passage might be made in 17 or 18 days. It having been proved impracticable to employ sails to any considerable extent in the presence of paddle-wheels, the caloric ship assumes on intermediate position, possessing the inconvenience of steam and the slowness of the clipper.
Sailing-packets have repeatedly made the passage between American ports and Liverpool in 14 days, and the solitary fact that the new power must compete with sailing rather than steaming vessels, is sufficient, until some new facts are developed, to establish the deliberate opinion that the experiment is, so far, a failure. The argument that if these engines can move the vessel at all, still larger ones can propel her with any velocity required, smacks too strongly of the school-boy to require attention.
Of tho success of the air-engine for stationary purposes there is more room to hope. Any desirable weight and space may be allowed for many purposes on the land, and this fact has been made available in the design of some steam-engines for such purposes.
The pumping-engines at the Cornish mines in England are celebrated throughout the world for their superior economy of fuel, although the arrangement of the engines and hoilers and proportion of power to their weight and space would prove a most miserable failure if applied to marine purposes.
It cannot be too often repeated that while it is theoretically possible, by the steam-engine, to obtain many fold more power from coal than at present, it is still more so, even to an infinite degree, by the caloric engine. There is a fundamental principle involved in the "regenerator" of Ericsson, Stirling, and others, which, could it be employed without drawbacks or losses, would allow one ounce of coal per day to pump out the Niagara river, and keep it dry.
That principle is the transfer of heat from the outgoing to the incoming medium ; or, to generalize the expression still further, it is the successive transfers of heat from a highly expansive medium to one which is less so, and back again.
Many practical men oppose this doctrine, and contend that the losses, by obstructing the passages, &c, are always necessarily equal to the gain. This is a mistake. There is no fixed relation between these quantities at all ; the loss may, by bad workmanship and bad contrivances, be greater than the gain, or it may be less, in a proportion which it is the object of the caloric experimenters to determine.
The subject has been considered at a meeting of the Institution of Civil Engineers (British), the general impression, as we gather from the report, being against the possibility of thus increasing power.
Now we wish to suggest a theoretical case, as follows : Suppose a certain quantity of air, of iron, and of heat, to be inclosed together in a vessel from which neither could escape. Now if the quantum of heat could be first concentrated in the metal, then diffused in the air, then again in the metal, and so continually changed, would not the pressure on the inside of the vessel change with each transfer of heat ; and would not a piston, fitting properly in an open end and properly balanced, be alternately driven out and in with a certain degree of force, and that without any escape of heat?
This question can only be answered in the affirmative. The heat when in the small volume of metal would expand it but a trifle; transferred to the larger volume of air it would develop a power proportional to the difference in expansion between the metal and the gas with equal increments of heat.
This is the simplest case that occurs to us by which to illustrate the fundamental principle of the regenerating engines. The particular arrangements, using the same or different air, the wires, tubes, and other details, are all merely modes of application. There is the principle, one which has yet to be proved to be of any considerable value, but which theoretically is able to multiply the present effect of heat to an indefinite extent.
The words "any considerable value" are used in this connection, because the principle of transferring heat from the outgoing to the incoming medium is actually employed in the steam-engine every day and in every direction. Each unit of heat that is transferred from the exhaust steam to the feed water is so far a step in the direction which Ericsson and others are now diligently exploring.
Air or other gases are used only because they are supposed to offer better facilities for extending this principle.
The question with which we commenced this article cannot be answered properly without a knowledge of all the results of the experiment. These have not been published, and the reluctance with which the facts are doled out is perhaps one of the most remarkable features of the whole affair. The paucity of facts with regard to the trip to Washington is notorious.
The earlier trial trips in the harbor, so far from being careful scientific experiments worthy of the importance of the subject, have appeared like child's play, - a sort of "sell" played off on the reporters, - an effort to manufacture
public opinion by wine and models in the cabin, or allowing gentlemen to amuse themselves by riding up and down on the pistons. It is believed that none who, from their position or profession, were supposed to be in any degree familiar with mechanical engineering, were invited to the trial trips.
We are positive that no names of those employed on the seventy or eighty steamships, or on the twice that number of steamboats running from this city, or in or about the several large and small machino shops, were appended to the document affirming its complete success, as published in the papers of January 12th ; and it is equally true that no editor or reporter was invited to either trial trip from the three prominent mechanical journals of this city, although the second trial trip was for the especial benefit of the press.
Such a policy is perfectly proper in the early stages of an invention, but is not the way to convince the world of its complete success when it is finally and fairly brought out.
In conclusion, let us again briefly define our position. We recognise the possibility of a great economy over that of the steam-engine, but deny that its practicability has yet been demonstrated. We look with considerable interest to the performance of the various air-engines now in construction, among which those of the Evening Post, mentioned above, are considered quite promising, and will keep those who choose to rend, posted up on the subject, to the best of our ability.
While endeavoring to do justice to the subject, we profess to hold no prejudice with regard to the claims of individuals, and hereby agree to give full credit to the first proof of superior economy which shall be presented by the working of any air or other engine, measured either by the friction-brake or by the performance of any measurable work.