1 AUGUST 1840, Page 14


1, St. Martin's Place, Trat'atgar Square, 31st .1111F WO. Site-4 feel very greatly beholden to you for the valuable editorial wool and the space you have ;slyest to it in yoour valuable col UMIIS of last Sunda, Si) I trust that you will favour me with the insertion, in your very next pipe. of iny explanation of a little misnomer that has escaped from the peu of vie tidented and impartial reporter of a trip to Footscray in my steam -catnip, Near the conclusion of that well-written report, your friend ssys, "Maeerodt is a tabular boiler, as are most of the other road-locomotives ; all beieg, in nit respect, modifications of Gurney's, and so far Neatly safe." Now, Sir, ;emit Inc to infirm you and the piddle, that " so thy " as so.Psy goes, the inlimmeies is correct ; but mine is not of' the kind which engineers understand and call by the name of a "tubular boiler." The Lard fiarbiti I tulodor tisitii; properly so called, and as constructed first in America and then by Mr. JAW, Mr. GURNEY, Messrs. MAUDSLEY 1111t1 FEILD, are composed of tubes of • one to one inch and a half diameter, disposed snore or lees like the skeletons( a horse, or in a spiral cone, so as to vu lain the lire within, which lire enve• lops the entire surlbee or the tubes, whieh are full of water. 'rite steam p. , aerated in these, small tubes is generally collected in some kind of " receiver" at the top, but the misfortune Lis always !men, that the huhldes of the steam with such an intense lire as is required to enable such smell boilers to propel a heavy carriage on all the conditions of a turnpike-road, see sure now ash then to push out the water beliwe them ; a part of a tube is then left dry, becomes red-hot, a stroke of water gets into it, when " bang " it goes. nil was the "remora " of the highly-taleeted and philosophical( Mr. 0 eaSSI, of Sir C. DANC E, Mr. F en. o, mad others. At a more moderate IWCSitlre than that required for common-road locomotion, Mr. Cute NE l.'s boilers and simple vibrating engines work admirably ; and it is astonishing that they were not more generally used, even 14 mere absolute safety sake, in factories, &e. But at the pressure of 200 and 300 pounds to the square inch, at whieb I find it necessary to work tat Wry soft hilly roads in winter, the water will be expend from the tubes. My boilers have no analogy whatever with Mr. Gensav's. They are pro- perly called cylindrical boilers ; consisting of 150 cylinders set up vertically, connected together at the top and bottom by hollow screws of (dime is inch bore, which keep up a peiq'ect circulation of water below anti steam at top. These cylindeis are four tic! IC diameter, and being only two-tldrds tilled with water, t here is a 'from' sa,:face of water in each for the steam to escape from— above Iwo cillare inches of sarface ip all; just as from so many colfee-p.oti only half-fall. Besides the upper portions of all the 150 cylinders cantainutg dry steam, I place other cs !hiders transversely- over them, which altogether forms a vast reservoir of steam. 1 have another boiler, far superior even to that which your reporter justly says is fifty-horse power, whilst only four feet cube in size. 1 hi:pe soon to /ion, thc means of' introduciag it to the public; but at present, and for a long time past, 1 have sutl'ered with my tinnily all the extremities of neglect, contumely, and destitution, even to the wait of the necessaries of life and shelter. But this will all appear in the two ferthcomme solo flies of my Memoirs, the first and second of which you did me the honor to eulogize in the Spectator of May Intli of last year.

With high cot (mil zInd thanks, believe me, Sir, your obedient servant,