Mr. Editor. - Dear Sir, - When a man is set upon by a crowd, it's but " a small request" that the on-lookers allow him room to defend himself) and as you and your readers have stood by and seen me considerably cuffed, in fair return just give me room to swing my arms a bit, without any sly poking, till the odds are nearer even. First, let me deny having written formerly only to injure Wethered & Cherevoy, as your correspondents wish to aver. I might claim to be "a friend of truth and fair play," as well as some of them; and the article of B. of Brooklyn was a sufficient incentive to call out such, without any spiteful feelings in the matter. In that answer you will find nothing but the most simple and direct reply, and I leave it to you and your readers, if in that they can find any sufficient provocation for such a general assault. Had I wished to injure the " well-earned reputation" of W. & C., a very different view of the case might have been presented.

Now to Mr. Chorlton, my first assailant in your last number. At the earnest request of Mr. Wethered, in the summer of 1859,1 consented to have two of my houses heated by his new boiler. He took the dimensions, calculated the requirements, and put up the apparatus accordingly. Not professing to be "au fait" on boilers, this being my first, I was not so foolish as to desire W. to put in less pipe than he thought necessary. The job was to be thoroughly done, and a written agreement was made "to heat the houses satisfactorily," which I think was not done. Now, Mr. Editor, you and your readers can judge whether I or Mr. Chorlton (who tries to prove that the amount of pipe was entirely inadequate to the buildings) most effectually injures W. & C. It is necessary now for a fair hearing that your readers get the facts of the case further. First, W. & C. put in a No. 4 boiler for me, which, after testing, they had taken out and replaced by a No. 5. This, when the pipes got hot, threw the water from the tank in such a sudden, heavy, and unbroken flood, as I never heard of any other boiler doing; and one night, after an absence of two hours, (having left the water above the flow pipe in the tank,) I looked in the tank and saw only, before the match went out, that the water was too low; and not suspecting that the boiler could be empty in so short a time, turned cold water in the tank; and soon after, going out to the boiler, found the water extinguishing the fire.

W. & C. next day put a No. 4 boiler in place of that destroyed, (not having a No. 5 ready.) This was not expected to heat sufficiently, but it did so well that, rather than risk another tearing down in winter, I kept it till the next summer, and I have not been slow to say that it did much better than ever was expected of it in keeping the frost out. As to its boiling the water, it once caused the same alarming overflow at the tank, as the No. 5 had done, which I supposed was boiling; but on talking with a well-versed mechanic, he was of opinion that the water never had boiled throughout, that steam was generated in the boiler, which drove the water out of the pipes, in consequence of the too great distance of the expansion tank from the boiler.

My second assailant, Mr. Wightman, under the guise of friendship accuses me of writing for " the purpose of injuring" W. & C.; not a very friendly accusation, entirely uncalled for, and which I deny. He says I told him that W. & C.'s apparatus had given me "perfect satisfaction." Let me ask Mr. Wightman if I didn't tell him the history of my boilers, destruction, etc; and how is it possible I could tell this with "perfect satisfaction" appended, to a friend, three weeks after the notorious destruction of my boiler? Wightman tells of ten boilers of W. & C.'s which give the greatest satisfaction. I only spoke of my own, which I am thankful for having had replaced by one of Hitching & Co.'s; and I believe I am not alone in this; and that, too, in more experienced hands, and where the boilers had competed on the same grounds.

B. of Brooklyn, instead of answering my charges in a manly way, and signing his name, as called on to do, neither admits nor denies that his former letter referred to my place; but seemingly wants to bemuddle the matter by proving both. Like some pettifogging lawyer, he dodges around to escape a straight shot, and with his own crooked gun (in true Irish fashion) tries to shoot me around the corners. I stand by my former letter, and deny that I found the pipes cold and the boiler red hot before turning cold water in the pipes. I never saw the boiler red hot, though B, with his far-reaching eyes and elongated ears, might; and though B. professes more knowledge than mine on boilers, I am of opinion that, with cold pipes and the boiler red hot, the pouring in of cold water would at once have exploded the boiler, (which was not done,) and the last of B.'s gratuitous assertions. I have not argued against W. & C.'s boiler particularly; in my case it was probably the arrangement of the apparatus that was wrong more than the boiler itself; an important item not to be lightly overlooked in such matters.

As your correspondents have praised W. & C.'s apparatus so highly, in justice to others let me state that, with a house and a half more, and three hundred feet additional pipe, my heating is now done most satisfactorily by one of Hitching & Co.'s new boilers, without half the trouble that W. & C.'s gave, and (at the risk of being called "close") with very little more coal than their No. 4 took to heat, very indifferently, three hundred feet less pipe. I have no desire to trespass on your space further, Mr. Editor, and shall not return again to this subject.

Yours respectfully, Jambs H. Park.

[The explanations in Mr. Park's letter make this boiler matter quite clear to our apprehension, and we think no more is necessary to be said on the subject, so far as those interested in the use of boilers are concerned. It is manifest to us, that in this particular case the boiler itself is neither to be blamed nor praised. Mr. Park very candidly admits his want of experience in the use of boilers at the time; and though he undoubtedly committed an error of management, it ought not, while there was any water in his return pipe, to have been productive of any result more disagreeable than filling his house with steam; provided every thing else was right, which clearly was not the case. We can readily perceive wherein this heating apparatus failed to give satisfaction, and could demonstrate it to the satisfaction of both parties. The whole subject may be summed up and dismissed, so far as our. readers are concerned, as follows: Mr. Park erred in management, but still had just cause of complaint, not against the boiler, but against the arrangement of the apparatus, if the parties were not restricted as to the size of boiler or length of pipe One erred in management and the other in judgment.

It is one of those cases in which there is a little error on both sides: a little concession, a little explanation calmly made, would settle this matter on a just basis, and preserve the "union*' in our parish: we mean such concessions as are consistent with the obligations of right and truth. - Ed].