96 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[Marcb, 



others, but made him dependent on himself; and this confidence was 

 rarely in vain, lor his errors were always less tliose of judgment than 

 consequent upon a hastiness of disposition, which, as it had met with 

 but little sympathy from the world, was but too apt to despise it. His 

 skill in providing for all occurrences was rarely baffled, and could not 

 easily bo surpassed, while his original and gigantic conceptions, how- 

 ever nuich beyond the progress of his age, were seldom beyond the 

 bo\inds of ultimate practicability. 



That his name is but slightly known, and his labours consequently 

 little appreciated, is by no means a result of their unimportance, but 

 the effect of concurrent circumstances, which, as they can elevate in- 

 significance, too often obscure merit. When he had conceived a plan 

 by the resources of his mind, and confirmed it by experiment, the very 

 Viistness of it surpassed his means of execution, and prevented it from 

 being carried into effect. He was himself no financier, and the asso- 

 ciations he formed with Vivian and others were either insufl!icient in 

 their extent, or turned more to the profit of his colleagues than himself. 

 It was true that he left no means unsought of obtaining the assistance 

 of others, but those who had capital feared to engage in enterprises to 

 which they were unaccustomed, while those used to business had no 

 disposition to deviate from the track in which they were long practised 

 and successful. It is the nature, indeed, of great monopolies, that 

 their very success engenders want of activity, for none feel so little in- 

 clination to engage in new processes as tliose who are accumulating 

 wealth by old ones. It is this that deadens the progress of the iron 

 trade, of distilling, and many others ; and the manufacturers, instead of 

 supporting new inventions, spurn them as associates, and trample them 

 down as rivals. It was the support of this influence which gave power 

 to Watt, while it cramped the energies of Trevithick ; for without 

 the aid of Boulton, the former might have wasted his life in experiments, 

 or, Hargrave-like, have been supplanted by another Arkwright. Tre- 

 vithick wanted but this to compete with Watt in worldly prosperity, 

 and he wants not this to ecpial him in the height of his genius, the 

 greatness of his works, or the wide-extending influence of his 

 inventions. 



That the memory of Trevithick has not received the honours which 

 have been conferred upon others, is a neglect which has been shown to 

 many of our greatest names, and proceeds less from our want of venera- 

 tion for men of genius than from our national character. We do not, 

 like Frenchmen, dread a rival near the throne, nor are we, like Ameri- 

 cans, fearful of others denying to us what we are scarcely known to 

 possess. We are rich enough in illustrious names to consider their 

 admission in o\n- domestic habits and our thoughts as a sufficient sacri- 

 fice to fame, and it is only on the instigation of some provincial that we 

 raise statues to those who live in our hearts. Our population in the 

 north, however, less fertile in their contributions to the shrine of 

 genius, and more remarkable for local preference than extended sym- 

 pathies, give a greater share of admiration to the few of whom they 

 dare to boast. The English, in acceding to their suggestions, while they 

 commemorate inferior names, create mementos of their own neglect. 

 WHiile, therefore, there are three memorials of Walter Scott to one of 

 Shakspeare, and to Milton none, we must not consider the many tri- 

 butes to Watt as emblems of superiority, but as proofs of a better fate. 

 It is to this tha't we must attribute that a statue is rising to Watt in 

 Manchester, while Brindley's merit still relies upon the glorious memory 

 of his canal. We may carry, however, this self-confidence too far, and 

 where we meant only to show hospitality, may have brought in strangers 

 to master our own children ; when we see the generosity of the 

 American Congress to the spurious claims of Fulton, and the gratitude 

 of Peru for the labours of Trevithick, we are called upon to offer some 

 honour to his name, and to show that we are as proud of the inventor 

 of the high-pressure machinery as we are conscious of the benefits we 

 derive from his railway locomotives. But, neglect him as we may, the 

 name of Trevithick will live while his engines annihilate space in the 

 Old World, and in the New control the current of the Mississippi, and 

 disgorge the mountain riches of the Cordilleras. 



MR. OLDHAM'S SYSTEM OF WARMING AND 

 VENTILATING, 



AS iDOPTED .41 THE B.\NK 01' ENGLAND AND BA^K 01' lnl,L.\NI>. 



Sir, — As the best mode of heating and ventilating apartments and 

 buildings is still an undecided matter among scientific men, I avail 

 myself of your journal to draw public attention to what appears to me 

 to be the best among the various plans and patents of the present day. 



At a late meeting of the Royal Institution, Professor Brande, in the 

 course of his Lectures on Heat, and in considering its transmission and 

 diffusion by means of currents, pointed out the advantage of aiding the 

 operation of tliose currents by mcclmnical means. 



In illustrating this mode of conveying heat where extensive apart- 

 ments are to be acted on, and where either a large volume of air or a 

 great quantity of heat may be required, the Professor described the 

 operation and etTect of an apparatus successfully adopted by Mr. Old- 

 ham, of the Bank of England, in which building it has been in use 

 during two years, having previously been adopted by him in the Bank 

 of Ireland, and where it has been in operation during sixteen years. 



When heat h conveyed by means of natural currents, these are 

 necessarily, and exclusively, due to the difference in the temperature 

 and specific gravity of the column of air, when heated, relatively with 

 that of the surrounding atmosphere ; the force of these currents, and 

 the body of heat they are enabled to transmit, are therefore necessarily 

 languid, compared to what may be effected by artificial means. 



That steam is the best medium for the transmission of heat is now 

 too well known to require much illustration. Its superiority over 

 water (independently of the greater facility with which steam is con- 

 veyed to a distance) i^ derived from the extraordinary quantity of heat 

 which water contains when in the state of vapour — a cubic foot of 

 water, in the form of vapour, having the power of giving out nearly 

 eleven times more heat, than the same body of water could when in its 

 liquid state. 



The mode hitherto adopted in many establishments, and in the large 

 cotton-factories, is that of conveying steam through a continuous series 

 of cast-iron pipes, so arranged and extended, through the several 

 apartments to be heated, that each shall he supplied with a given 

 length and surface of pipe, proportioned to the dimensions of the 

 apartments to be heated. 



This is manifestly a mode attended with great inconvenience and 

 expense in the conveyance of such pijies, in their liability to leak; 

 and in the want of uniformity in the temperature of the several parts 

 of the rooms in which those pipes arc introduced. But there is yet 

 another and more formidable evil attending this niude of heating, 

 namely, that while it merely conveys heat to the already existing air in 

 the chambers to be heated, it has no relation to the condilion of that 

 air, or the supply that may be required, or the changing and purifying 

 the same. In a word, the system, by means of steam-pipes, has the 

 power of heating, but not of ventilating. It has no relation to the 

 purity or impurity of the air to which it imparts the heat ; and it is a 

 fact, that giving an additional supply of heat to an apartment may 

 even be prejudicial, inasmuch as such apartment may require ventila- 

 tion, that is, change of air, rather than heat. 



Now tlie process of heating adopted by Mr. Oldham has this peculiar 

 and distinguishing characteristic, which gives it a claim above all others, 

 namely, that it both heats and ventilates at the same time, to any extent, 

 and with any required rapidity. 



As fir as health and comfort arc concerned, heating and ventilation 

 should never be separated. Mr. Oldham's process and apparatus most 

 effectually supplies this desideratum. 



Doctor Ure, in his inquiry into the modes of warming and ventilating, 

 observes, that " the great principle of ventilation is, never to present 

 the same portion of air twice over to the human lungs, but to supply 

 them at each fresh inspiration with pure aerial particles in a genial 

 thermometric and hygromctric condition." 



Where heating is alone attended to, as in the case of heat conveyed, 

 by steam in metal pipes, it becomes necessary to provide currents of- 

 cold air, to supply the required continued change in the apartments 

 for the pur'poscs of ventilation. It is manifest, then, that the best 

 principle must be, first, to heat the required volume of fresh air, and 

 then introduce it to the apartments to be heated and ventilated, instead 

 of efl^ecting this double object by two distinct processes. This is 

 effectually accomplished by the plan of Mr. Oldham under consideration. 

 The modus operandi is as follows : — A body of pure air, of any required 

 volume, and passing at any required velocity, is forced by the aid of an 

 air-condensing pump into a chamber or chest, where it is heated in an 

 ingeniously-contrived, but extremely simple apparatus, by means of 

 cross currents of steam. The peculiarity of this contrivance is, that an 

 ascending body of air, on entering this chest, divides itself spontaneously 

 into any required number of thin horizontal films, by which a very 

 extended surface is exposed to corresponding steam-heated metal sur- 

 faces. Instead, therefore, of passing the steam through a scries of pipes, 

 along which, hut in an opposite direction, the condensed water has to 

 return, it is conveyed at once from the boiler into the chest or condenser, 

 (which, in fact, it is,) where, on having parted with its heat to the air 

 as above described, it is condensed, and returned directly to the boiler. 

 The chest or condenser, in the apparatus at the Bank of England, is 

 but three feet square, yet the body of air to be heated, while passing 

 over but 3 lineal feet, spreads itself over no less than I j-1 superficial 

 feet, and coming in contact with a corresponding superficies, heated by 

 the steam, it necessarily receives a very large supply of heat in a short 

 space of time. 



