1843.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



always share in the same external style and expression, though erected 

 for and adapted to very different purposes. We might as well expect 

 the face of each individual whom we meet to express his particular 

 pursuit and profession, and lay open to us his thoughts and intentions, 

 as to look upon the facade of a building as the index of the purposes 

 for which it was erected. The human face, indeed, is considered, 

 and with unquestionable propriety considered ;;s the index of the soul, 

 as the outward sign by which we may read the feelings of the man, 

 and being accustomed from the dawn of reason, perhaps intuitively, 

 perhaps from experience acquired in infancy, to consider the features 

 as indicative of the various passions, and our more mature years con- 

 firming this experience, we become so firmly convinced of the truth of 

 these principles as to rely on the inferences we draw from them; and 

 believing all men subject to the same feelings, the same joys and 

 sorrows as ourselves, we make no distinction in our application of 

 them ; but consider, that whatever may be a man's rank, his race, his 

 sation, or his name, without regard to climate or complexion, whether 

 he be an inhabitant of the polar circles, or the torrid zone, we may 

 read in his face the passions of his soul. But though he may thus 

 plainly and universally read the feelings of the man, the cause of 

 those feelings is yet hidden from us ; and although the expression of 

 the features we look upon may induce in us corresponding emotions, 

 we are unable to divine its origin. We may thus see the emotions 

 of joy or fear spread rapidly through a crowd ignorant of their cause; 

 each individual being immediately affected by his neighbour's ani- 

 mated look and gesture, or though himself remote from danger, be- 

 coming at once alarmed by the fear expressed in surrounding faces, 

 which indicate that something unknown is to be dreaded, by its por- 

 tentous indistinctness, rendered yet more fearful. In the arts of 

 painting and sculpture, the artist copying the human face and figure, 

 gives to bis productions the expression he may choose, and in pro- 

 portion to the intensity of that expression is the emotion raised, but 

 the cause of such expression is sought for in the accessories, or com- 

 binations of the piece ; and our experience of human feelings leads 

 us to judge whether the passion expressed is in accordance with its 

 exciting cause. If then in these most expressive arts the feelings 

 excited do not lead us to the reason which induced the artist to give 

 such particular expression to his work, if we are liable to be deceived 

 in interpreting the meaning of allegorical painting and sculpture, how 

 shall we in architecture, where neither nature nor experience teach 

 us to decide, how shall we say what particular character shall indicate 

 a particular building. We have here no standard of expression; the 

 ideas of different nations on this subject are as various as their lan- 

 guages: and in examining the remains of ancient edifices, we do not 

 decide upon the purposes for which they were built, from their ar- 

 chitectural character, but the acccessories and combinations of their 

 construction. 



The Gothic style, which is by us considered as peculiarly charac- 

 teristic of a church, would most assuredly not be viewed in the same 

 light by an ancient Greek. One of our large churches, or cathedrals, 

 would unquestionably produce emotion in the breast of any man who 

 had a soul to feel ; but this, I am persuaded, would arise from the 

 grandeur of the structure, from the insignificance into which the spec- 

 tator sinks while gazing through "the long drawn aisle," or looking 

 up to the " arched and ponderous roof," and from the majestic evidence 

 of superior constructive skill around him, and not from any feeling 

 that such a style proclaimed, by its silent but unerring expression, 

 that he was in the House of God. As on the human face we may 

 read the feelings of the mind, may trace gaiety, gloom, resolution, or 

 despair, so may we be impressed by the design of a building with 

 the emotions corresponding to sublimity, grandeur, magnificence, or 

 elegance ; but as we cannot determine the cause of the passions 

 expressed upon the human features, so we cannot impart to any 

 structure, vary its character as we may, the power to express whether 

 it be a temple, a palace, a senate-house or an exchange. And as 

 mankind differ as to the expression proper to be given to a statue or a 

 painting, so will they disagree as to the character proper for a build- 

 ing, nor can we hope that architecture shall speak in the same 



37 



language to us all, until all shall not only have been educated alike 

 but shall have acquired the same prejudices, habits, tables, and 

 feelings. 



A. D. 



THE VELOCITY OF WATER IN VERTICAL PIPES. 



We have received a voluminous communication from Mr. Shuttle- 

 worth, purporting to be a reply to the notice in our December number, of 

 his system of railway propulsion. The extreme length of his letter, 

 which occupies thirty closely written pages, would be a total bar to 

 its insertion, even were it an argumentative treatise instead of being 

 almost entirely discursive. We have received from another corres- 

 pondent, however, a communication on the same subject, deserving 

 much more attention, in which the writer states argumentatively his 

 objections to two of the positions introduced incidentally in the ar- 

 ticle on Mr. Shuttleworth's hydraulic railway. The question of the 

 velocities acquired by water flowing down vertical pipes is, indeed, 

 important and interesting; we shall therefore, after allowing our corres- 

 pondent to speak for himself, pursue the inquiry, not only for the pur- 

 pose of defending our previously expressed opinions, but with the 

 view of arriving at some, satisfactory conclusions on a subject that 

 has given rise to much discussion, and respecting which, as it appears 

 to us, very erroneous notions continue to be entertained. 



The following is the letter to which we refer. 



"London, December 21s/, 1^12. 



"Sir — Agreeing with the writer of the remarks on Mr. Shuttle- 

 worth's Hydraulic Propulsion system, which appeared in your Journal 

 of last month, that it is a pity to see so much talent, ingenuity, labour 

 and expense lavished upon an invention evidently impracticable, I 

 must at the same time call into question the reasoning by which the 

 writer has arrived at this conclusion, or at least that part of it which 

 relates to the flowing of water through a vertical pipe ; I do so more 

 particularly, as the subject is important, and, I believe, new: also 

 because, from the editorial character of the article, it might mislead 

 many of your readers. I shall endeavour to show that the writer has 

 committed two important errors in the fifth paragraph of that article ; 

 first, in explaining the uniform flow of the water in the column, by 

 the cohesive attraction of the particles of water. Secondly, in 

 saying that this uniform velocity is half that due to the height of the 

 column of water flowing through a small orifice, he appears to think 

 that, supposing the height of the water constant, the issuing velocity 

 diminishes as the aperture increases. Now, it is evident that such is 

 not the case, as by increasing the diameter of the orifice, the friction 

 of the sides decreases in a greater ratio than the area of the orifice 

 increases. This is so evident, that I believe it requires no further 

 explanation. 



"Assuming the Irishman's privilege of going backwards, I shall first 

 endeavour to demonstrate the second error, by proving the velocity 

 of the issuing water (and therefore, as will be proved in the second 

 part) of the whole column, to be expressed by the formula \ x, 

 where x expresses the height, modified by the resistance of the air 

 and friction. The friction, however, may be omitted, as being very 

 trifling in a vertical pipe, when compared with the retarding effect of 

 the atmosphere. 



"When the water first enters the pipe, there is a slight decrease of 

 velocity, in consequence of the " vena contraeta," which in all works 

 on hydraulics, is generally allowed for, by changing the Q in the 

 above formula to 5; it then assumes a vertical direction, its velocity 

 increasing as the square root of the height, until the resistance of the 

 air, increasing as the square of the velocity, becomes equal to the 

 momentum ot the water. An equilibrium then existing between the 

 accelerating and retarding forces, the velocity would be uniform. As 

 will be seen from the following equations, it would require an im- 

 mense length of vertical pipe before this uniform velocity could be 

 produced. Let c represent tiie velocity, x the height, * the specific 



