313 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[Oct. 



cooatJDg the number of bricks, we could ascertain the quantity of raw 

 cement made, without the trouble of measuring it." 



This experiment not proving so successful as was desired, some 

 experiments were again made on a small scale, and subsequently on a 

 larger scale, in a small lime-kiln about four feet diameter at top, ^ud 

 six feet deep. 



" In this little kiln, than which nothing could have answered better, we 

 burned, at four successive periods of the same yoar, about 140 cubic feet 

 of raw cement. In the first of these batches of artificial cement we used 

 the same mixture as before of 5 measures of chalk, 2 measures of blue 

 clay, and half a measure of coal-dust ; and io burniD^ it, after putlinj in 

 shavings and wood at the bottom of the kiln, we laid half a bushel of coals 

 over the wood, then four bushels of the raw cubes, after which another 

 layer of half a bushel of coals, then four bushels of cubes as before, and 

 thus we continued applying the coals and cement cubes in alternate layers, 

 until the kiln was filled, using one measure of coals to eight measures of 

 raw cement, the former being broken rather small, so that no piece of coal 

 used exceeded au inch in thickness, and both being thrown loosely into the 

 baskets with which we measured them. 



In the third and fourth batches of raw cement prepared for burning at 

 the same kiln, we dispensed with the coal-dust altogether, using 5 mea- 

 sures of chalk to 2 of blue clay ; and we merely pounded and sifted the 

 chalk, without grinding the powder afterwards in the mill ; and in conse- 

 quence of there being no fuel combined with the raw cement in this mix- 

 ture, we used one measure of coals to five measures of the raw cement 

 cubes in burning ihem, which proportion we always adhered to afterwards, 

 as the best for this mixture." 



The remainder of the treatise details the numerous experiments 

 made by the General to test the strength of all kinds of cement, to 

 which we must refer our readers. 



In conclusion, we confidently recommend an attentive perusal of this 

 treatise to every one who may be desirous of obtaining sound practi- 

 cal information on limes, mortars, and cements. 



Wealths Quarterly Papers on Engineering. Part I. Vol. VI. Lon- 

 don : John Weale, High Holborn. 



The present number of Mr. Weale's journal consists of three 

 papers — I. "On the Principles and Practice of the Application of 

 Water Power," by Robert Mallet, President of the Geological Society 

 of Ireland. — 11. "Experiments on Locomotive Engines," by MM. 

 Gouin and Le Chatelier. — III. " Paper on the first Introduction of 

 Steam Engines into Naval Arsenals; and Machinery set in motion 

 thereby," by the widow of the late .Sir Samuel Bentham. 



The first paper contains an account of the projected Dodder Tle- 

 servoirs, near Dublin, and of the Bann Reservoirs, now in course of 

 construction. Mr. Mallet has likewise favoured us with a description 

 of his self-regulating syphon weir, which seems to us extremely in- 

 genious, and perfectly correct in principle, whatever it may turn out 

 in practice. 



" Over a common weir, or embaukment, is thrown a large flat-shaped 

 syphon tube, made of boiler plate, and for stifl'ness divided into several 

 parallel tubes by vertical plates. One end of this syphon (which may be 

 extended indefinitely along the crest of the weir) dips into the water 

 ponded above the weir, the other end lays open at the lower side of 

 the weir. The under side of the syphon tube reposes upon the 

 crest of the weir, and the Jeplh of the S'lpliun tube, or distance vertically 

 over the crest, is equal to the hei^fht to which the rise of water in times of 

 flood may be permitted, (in the instance shown equal to IJ foot). 



At such a level lielow the crest of the weir as it is determined shall be 

 the lowest to which the ponded water shall be wasted by the syphon, there 

 is formed a range of air holes, or simple apertures through the upper plate 

 of the syphon tube. The action of this arrangement is now very obvious. 

 Whilever the water above the weir continues at the ' standard level,' none 

 runs over or through the syphon; as its level rises above this, a sheet of 

 water flows over the crest of the weir, and also down through the flat 

 syphon tube, as part of the weir. This continues as the level of the 

 Water rises highi-r and higher, until it reaches that marked as the limit for 

 the ' highest floods,' that is, the level of the upper side of the syphon tube. 

 The moment the water reaches this point, the syphon, being quite full, 

 instantly commences to act as a syphon, and discharges a quantity of 

 water, euormously greater than before — a quantity due, nut to the mere 

 area of otcrjtow through the partially filled syphon, but to the area of the 

 syphon tube, and to the head of water now acting upon it as a syphon. 

 This vastly increased discharge, now more than a match for the supply of 

 the river itself, begins to lower the water above liie weir, and its surface 

 continues to fall until it reaches the point marked as the ' lowest level' that 

 it shall attain. Here the range of air holes are situated, and the instant 

 the surface of the falling water leaches these, air enters the sy;)hon, and 

 it directly ceases longer to act as a syphon, and becomes merely a part of 

 the weir conducting the ordinary overflow. This process, the sudden bring- 



ing of the syphon into action when the water reaches a given level, and 

 sudden cessation of its action again when it has fallen to a given level, 

 may be endlessly repeated ; and the effect of the syphon, when in action 

 and suitably constructed, is in fact very nearly the same as suddenly open- 

 ing a sluice, equal to its entire area, at the level of the bottom of the weir 

 or dam." 



Experiments on the discharge and How of water from orifice.s and 

 through tubes are much needed. Eytclwein's formula is generally- 

 adopted bv engineeis, though we much doubt whether it would be 

 found applicable if the height of the head of water were to exceed 

 a certain limit — say 10l» or 150 feet. 



The second paper — "Experiments on Locomotive Engines" — has 

 rather a formidable appearance ; the tables contain as iT,anv figures 

 as Mr. Adams employed in the calculation of Neptune's orbit. We 

 noticed an allusion to the fact of the dift'erence of pressure in the 

 cylinder and boiler being a function of the load, as a theorv of M. de 

 Pambour; — for this difference and the cause of it, we beg to observe 

 that Nature, and not M. de Pambour, is responsible ; although that 

 gentleman, we believe, first correctly interpreted her laws on the 

 subject. 



The last paper is a highly-interesting historical summary of the 

 labours of the late Sir Samuel Bentham. 



Tilt Indicator and Dynamometer, wilh their Practical ApplicatioM. 

 By Professor Main, of Portsmouth, and .Mr. Thomas Brow.\-, Engi- 

 neer. Loudon : Hebert, 1S47. 



The object of this work is to explain the use of two valuable in- 

 struments for ascertaining the work done by the steam engine. The 

 Indicator is one of the many of Watt's valuable instruments, and on 

 which that great man set high value, on account of its simplicity and 

 importance. By the application of the indicator the working condi- 

 tion of a steam engine is at once tested. The Dynamometer is intro- 

 duced into screw vessels for ascertaining the amount of pressure given 

 off by the screw shaft, and consequently the force the engine is exert- 

 ing to propel the ship. The use of both these instruments and their 

 application are very clearly explained in the little work before us. 



Letter to Lord John Russell, on the Defence of the Country. By 



JoHM Weale. 



Mr. Weale's object is to train for soldiers all the able-bodied men 

 who may apply for relief at the Union, and he very croakingly points 

 out the great dangers to which England is liable from the sudden inva- 

 sion of the Frencli. We should be very sorry to see England turned 

 into a country of bayonets; we much prefer tlie epithet of "a country 

 of shop-keepers." Let men be taught how to avoid war, and not teach 

 them the use of the carbine, to murder and pillage their fellow beings. 

 Knowirg Mr. Weale's disposition, we must say that we never sus- 

 pected hat he would have recommended such a system as he has 

 promulgated in the pamphlet before us. 



COLONLA.L RAILWAY PROGRESS. 



Madras and Arcot Itailwaij. — A company has been started to effect the 

 junction of these two important points in India. The line has been highly 

 recommended by Mr. Simras, the government engineer. Its length is 71 

 miles, and is nearly a dead level, the average inclination being only 1 in 633 

 feet; there is no tunneling, nor any cutting of consequence. The proposed 

 line is the first stage out ot Madras on the great western line of communi- 

 cation with Bombay and the military stations of Arcot, Bangalore, Hydera- 

 bad. Cannanore, and Tiichinopoly; and is second in importance to no line 

 in India. It will be constructed at .is low a cost as .£5,000 a mile. 



yiustralian liailway and Si/diicr/ Water- Works Company. — This colony 

 being in such a flourishing condition. It has been determined to introduce rail- 

 way communication on the same economical system as practised in America. 

 The line is intended to run from the port and town of Sydney to Richmond, 

 passing through Paramatta, Castlereagh, Windsor, and other places of minor 

 importance, with a branch from Paramatta to Liverpool; and it is also 

 intended to supply Sydney with water from the hills. This is of great im- 

 portance to that town, as it is at present supplied with water from a lagoon, 

 which is almost dry in the summo!- season. The line is 45 miles in length, 

 and can he constructed remarkably cheap, as government will find land, and 

 the country abonmls with a \ery hard and durable timber, called iron-bark 

 wood, particularly well suited for sleepers 'and rails, by merely arming the 

 edge with angle iron. 



