The Evening Star THURSDAY, JUNE 9, 1870.

Evening Star, Volume VIII, Issue 2212, 9 June 1870, Page 2

The Evening Star THURSDAY, JUNE 9, 1870.

Last week a description of an invention by Mr Peyman of a new style of bridge appeared in the Daily Times, which lias formed the subject of several letters in that journal, to which that gentleman replied. As the subject is one in which the Province, and through it the Colony, is deeply interested, we should fail in our duty were we to Neglect pressing it forcibly on public attention. We do this the more readily, because of our firm conviction that, in the construction of bridges in the Province, faults have been committed which have led to enormous unnecessary expense through their destruction,

and that much bettei) and more enduring structures might be put up at less expense. In adopting this view, we may perhaps be charged with hastily condemning wliat professional engineers have approved, and it may be said that they must bo better able to decide what is necessary than those engaged in other pursuits. To this we reply that by their works you shall know them ; and further, that while the details of construction may be fairly left in their hands, "the principles on which stability depends needs no special professional knowledge, but can be judged of by any who take pains to ascertain them. The educated public, therefore, are fairly entitled to a voice in the matter ; nor will the prejudices and foregone conclusions of _ professional men be overridden in favor of simpler and more suitable structures until the public voice speaks fully and decidedly in their favor. The controversy in the columns of our contemporary was not directly condemnatory of Mr Peyman’s invention. In fact the writer unconsciously indirectly recommended it, on the ground that somebody else had invented it before him. Another found fault with and poohpoohed the matter, because there were suspension bridges in the Province, and the reporter of the Times had called Mr Peyman’s invention a suspension bridge. Having examined the model, we are thus far able to correct the impression raised by the term “ suspension,” and to affirm that it cannot strictly be termed a suspension bridge, as it has properties that no suspension bridge, properly so called, ever had. One party claims to have thrown pipes of water across a river on the same principle ; but we presume lie is not clear on the subject on whicli he speaks, for lie talks of diagonal bracing, and the arch which by his process he had formed sinking to a level when the weight came upon it. As this would be impossible with Mr Fryman s bridge, it cannot resemble his invention. The idea, simply, is the application of cheap,. durable, and strong materials to form an arch capable of sustaining any weight be required to pass over it. Our forefathers made use of the best material they possessed, and learnt to put it together in the most enduring fashion. They did not know how to make huge castings such as our iron foundries turn out every clay. They could not manufacture thousands of miles of wire to span the Atlantic, nor draw out strands of iron, which, twisted together, should form a strong rope of .any desired diameter. But all this we can do. Our civil engineers have hitherto WllllvUll in. ilio of our hlipvyj and gone on building arches of brick and stone. Mr Pjsyman proposes to depart from the old routine, and use our new manufacture of wire rope to span iu one continuous length what they could only do by adding block after block of stone or brick after brick. At first sight it seems a strange idea to use so flexible a material lor such a purpose, but the object is gained in this wise ;—On each side of the stream he proposes to construct towers of strong masonry, just as is done with suspension bridges, and to pass suspension ropes across the stream precisely in the same manner; but instead of hangjng the roadway to these on a level by suspenders, he attaches to each side a wire rope below so as to form an arch when the upper and lower ropes are connected by rigid iron rods. The roadway is then laid upon the two lower lines transversely ; and abutting upon the masonry at each end of the bridge, it becomes firmly fixed, and capable of bearing an enormous load. Kor does the flexible character of the sustaining arches seem to be any drawback to its strength, for the rods that connect the two ropes together being rigid, prevent any undulation in the roadwa} r . We are disposed to think Mr Peyman has hit upon a plan that is capable of much more extended application than he seems to anticipate, and that improvements are capable of being made that will add much to its usefulness. At any rate, it is an invention that deserves better at the hands of the public than to be written down on such flimsy grounds as have been taken by its detractors. If its merits be what we have attributed to it, they should be tested on public grounds, for it gives the means of constructing cheap and durable bridges, and these are what we want.