different tale. Mr. Evans had a record of more than 600 bursts before he had one explosion, although the pressure was greater when the bursts took place than when the explosions happened *. I have myself witnessed enough to be perfectly satisfied that there is as much difference between a burst and an explosion of a steam-boiler as there is between the bursting of a cannon by hydraulic pressure or by gunpowder. It is well known that a cannon burst by hydraulic pressure is perfectly harmless, and it is also known by dreadful experience the effect of bursting with powder. In my endeavours to learn the nature and value of high steam I have been so fortunate as never to have had one explosion, although

* It has often been observed that just before one of these tremendous explosions has taken place, the engine worked more sluggishly than common, indicating that the explosion was caused by sudden generation of high steam, or by an explosive mixture having been formed in the boiler. I have no doubt that there are three kinds of explosion.

The first and most common cause is from the pressure of common steam. What is meant by common or pure steam, is such as has not been suddenly elevated, or such as has not been compounded with an explosive mixture, by the improper management of the boiler.

This first kind of explosion is quite harmless, as the boiler simply rends or gives way in the weakest place, which is caused from wear or some defective spot. The second, which I some years since accidentally discovered and published, arises from the water getting too low in the boiler. The fire then impinging on that part of the boiler which is above the water, causes the heat to be taken up by the steam, which rises by its superior levity to the top of the boiler, causing it sometimes to become red-hot, and so elevating the steam to a much higher temperature than its pressure would indicate. Now, when the boiler is in this state, and the safety-valve suddenly raised, the water will be relieved from the steam pressure, and rush up amongst the surcharged steam, which thus receives its proper dose of water; at the same time, that part of the boiler which has been raised in temperature giving off its heat to the water so elevated, steam is generated in an instant, of such force as no boiler can resist. This kind of explosion has of late years been very frequent and disastrous, particularly in America.

The third and less frequent kind, although most terrific, is undoubtedly caused by an explosive mixture having been formed in the boiler. It has long been known that hydrogen has been often liberated by the boiler being overheated by improper stoking, as well as not being properly supplied with water; but simple hydrogen cannot explode,-and where it could get its atmospheric air, which is absolutely necessary to form the explosive mixture, it has been difficult to understand. We have only, however, to look at an air-drawing feed-pump, and the source will be readily seen. It is frequently the case that the feed-pump draws air as well as water, arising from its unsoundness, &c. The more air the pump draws, the less water is forced into the boiler; of course the boiler is more and more exposed to the fire, and the heated parts of the boiler become oxidized, and rapidly liberate hydrogen; and as sufficient air has been pumped into the boiler to form the mixture, it will be ignited by an overheated part of the boiler, and the tremendous effect can only be equalled by an explosion of gunpowder.

I have very often had the steam up to 100 atmospheres pressure, but I have had more than 100 rends or bursts.. In the Adelaide Gallery, where the steam has been up daily to an average of 450 pounds to the inch for more than four years, and where many times the exhibition of the steam-gun has been stopped in consequence of the bursting of the generator, yet no one heard any report, although many were within a few feet of the generator. In fact, I never knew a brick to be disturbed by the bursting of the generator. About ten years since I was exhibiting the steam-gun to a great crowd, when in the middle of a volley, the steam dropped, and the balls refused to leave the barrel. I immediately ran to the furnace, and found a rend about eight inches long and one inch wide in the centre of the boiler, which was three and a half feet long, seven inches diameter, and three quarters of an inch thick, of wrought copper. Having apologized to the company for being obliged to stop the experiment as the boiler had burst, they exclaimed that it was impossible, for they heard no explosion; my answer was, " Come and see,' which many did, when to their astonishment as well as pleasure, they found that the rend was very great. One gentleman in particular was extremely gratified at being present when the occurrence took place, he being an owner of steamengines.

One of the experiments of the Committee was, "to ascertain whether intensely heated and unsaturated steam can, by the projection of water into it, produce highly elastic vapour. Abut eight years since I published a treatise on the cause of explosion of steam-boilers which found many believers. The Committee of the Franklin Institute have been making experiments to ascertain whether surcharged steam could have its power increased by adding sufficient water to give to it its proper density. My experiments, however, to prove the fact were conducted in a very different manner from those of the Committee. I built my fire under the bottom of a very strong generator, which would bear at least a pressure of 300 atmospheres.

The object of this great strength of the generator was not only to enable me to make my experiment without danger, but to surcharge the steam at a very high temperature, so that there should be no mistake as to the result. The fire was made at the bottom of the generator, about a quarter up the sides, and about as much above the water as below it, observing at the same time to have the fire much more intense above the water than below the steam; but no fire was

made on or near the top of the boiler, believing that heat would not descend any more in steam than in water. (This fact is now completely established by a new modification of a boiler, which owes much of its success to the property which surcharged steam possesses in transmitting heat, the particulars of which cannot be made public until I have obtained my foreign patents.) If I had made my fire on the top of the boiler, as was done by my countrymen in their experiments, I should have made the same mistake which they did, and instead of surcharging the mass of steam, I should only have surcharged a small film next the heated metal, and left the rest perfectly saturated with water, and quite unfit for receiving a jet of water, which could only serve to lower the temperature and power, which was the case in their experiments. At the top of my generator the temperature was at least 3000 degrees, ascertained by an alloy that fused about that point; the temperature of the steam in contact with the water was about 300 degrees, the mean temperature about 1500 degrees that, together with the heated sides and top of the generator, furnished heat enough to make the indicator rise at each stroke of the pump from 50 to 100 atmospheres ; and as the steam was constantly blowing off at the safetyvalve, which was loaded at 5 atmospheres, the steam would fall to that pressure in about 15 seconds. The oscillation of the indicator was from 4 to 5 times per minute; its rise was instantaneous, but its fall gradual.

The ninth experiment of the Committee was, " to repeat Perkins's experiments, and ascertain whether the repulsion stated by him to exist between the particles of intensely heated iron and water be general; and to measure, if possible, the extent of this repulsion with a view to determine the influence which it may have on safety-valves. The experiments made with the perforated thick iron bowls, as far as they went, were very satisfactory. The water standing in the bowl heated up to 800 degrees without passing through the metal, until the metal had lowered its temperature, would be easily seen by any one, and would be an interesting one to be repeated in a lecture room.

"The Committee now proceed to give an account of an unsuccessful attempt to repeat Perkins's experiment referred to in the query. As it does not seem to bear upon the application of the safety-valve, they did not deem it necessary to encounter the expense of the apparatus necessary to a further trial."

[To be continued.]

ÖN PARLIAMENTARY PROCEEDINGS UPON PRIVATE BILLS.

EVERY succeeding session of Parliament adds new and increased importance to this subject, and, as yet, the attention of the public in general has never been directed to it. Indeed, with the exception of the solicitors, parliamentary agents, and other individuals, whose business it is "to get Bills through the House," few persons are acquainted with the mode in which the proceedings upon private bills are conducted, and none care to inform the public upon a system which works with great advantage to the limited number connected with it. Knowledge is power; and so long as the power thus conferred is restrained within bounds, the pursuit of such knowledge is confined to the few persons whom accidental circumstances in the routine of life direct in its track. But the public are now sore pressed, by reason of their own ignorance. It is high time that the veil of obscurity in which the private branch of our legislation has been enveloped should be torn aside, and that the public should gaze upon a system, of the effects of which they are alone sensible, but the operation of which is less known, though far more visible to them, than the operation of the powers which cause the various forms of material substances with which we are surrounded.

From the passing of Magna Charta till the reign of Richard III., no distinction appears to have been made between public and private acts, and the statutes contain but a very few enactments of a private nature during that period. In the first year of the reign of Richard III. (1483), a classification of the statutes took place into public acts and private acts; and from this era we may date the importance which the latter gradually assumed. The private acts which were passed at that time, and from thence during a considerable period, were strictly of a personal and individual character and application; such as acts for attainders, and for the reversal of attainders; acts for the confirmation of letters patent, for the enjoyment of lands; acts for restitution, and for granting subsidies to the king; acts for individuals, chiefly the nobility of the kingdom, for the assurance and settlement of their estates, or validation of their marriages, naturalization bills, &c. course of time, the private bills, in addition to those before mentioned, assumed a new and more extended character, affecting not only individuals, but large classes of persons, and extensive districts, such as inclosure and allotment, road,

harbour, navigation bills, &c., so that in the year 38th George III. (1797), a new classification of the statutes was made into Public General Acts,' 'Local and Personal Acts,' and 'Private Acts.' This arrangement lasted till the 43rd George III. (1803), when the title of the statutes for that and the following year was changed to Public General Acts,' Local and Personal Acts to be judicially noticed,' and Local and Personal Acts not printed.' With the addition to the title of the second class of acts, that Printed Copies of the same might be given in Evidence,' this classification lasted till the 54th George III. (1814), from whence, up to the present time, the statutes have been divided into 'Public General Acts,' 'Local and Personal Acts,' declared public, and to be judicially noticed,''Private Acts printed by the King's Printer, and whereof the printed copies may be given in Evidence,' and 'Private Acts not printed.'

Thus in the earlier portion of our civil history, the private branch of our statute law has received no distinct legislative notice from that branch which is of a general tendency. The subsequent separation and classification of private enactments at once shows the character and importance which belong to them, and the order in which that classification has been made evinces their degrees of public interest and relative connexion with the public weal. But although this branch of parliamentary legislation has assumed the important features which it now presents, and as the nation advances in wealth and eivilization, those features are still more strongly impressed upon it, in the increasing number of the highest class of private enactments, the Local and Personal Acts which are declared Public, and to be judicially noticed,' possessing in their operation and effect more importance than many of the Public General Acts,' the system upon which this branch of parliamentary legislation is conducted has scarcely been thought worthy of public attention, and has certainly never been regarded with that degree of interest which ought to be bestowed upon it.

The standing orders and resolutions of the House of Commons exercise but a very slight and imperfect control over the parliamentary proceedings upon private bills. These orders have been made, from time to time, as private bills have had a more extended operation and general tendency, and as the liberty of person and the rights of property have become better respected, with the intention it would seem that neither the one nor the other should be infringed, unless for the public good; but they have little or no operation be