I8-I50 



THE CIVIL ENGINEER AND ARCHITECTS JOURNAL 



2D9 



In oiJcr (o economise (lie compressed air, llie inventor gravely jroposes 

 to return it to the vacuum a, after it has acted on tlie piston of a liiyh- 

 pressurc engine. The mode of ellceting this olijcct is as follow s; fi;;. 2 

 shews a longitudinal section of a locomotive engine constructed according to 

 this invention. A is the receiver for containing llie eompri'sscd air, uliicli 

 passes through the \npc b to the valve-box, and from thence into the cylin- 

 der, so as to act on the upper and under sides of the piston alternately ; at 

 c c there are t«o valves, connected by a rod </, which is act'.:ated by a lever r, 

 which lever is connected in some manner (best known to the inventor) to the 

 valve-rod /; g g' ate two eduction-pipes, leading from the eduction-valvcs 

 c c to llie peculiar constnicled pHmps h and i, through « hich the air is intended 

 to pass, instead of passing into the atmosphere. These pumps, which are 

 placed within the receiver a, consist of a cylimlicat block of metal, having a 

 hole drilled through the centres, and connecled with the eduction-pipes n g'' 

 on tlie lop of each of tliese bbcks there is a valve opening upwards ; Ick :ire 

 cylindrical caps, made to lit air-tight upon the blocks h i ; these caps are also 

 provided with valves/, opening upwards, and are connected to the ends of a 

 beam m. by means of rods n n sliding through stuffing-boxes fixed on the top 

 of llie receiver. The beam m, it is said, may be worked by hand, in the man- 

 ner following. Suppose the condensed air to be passing from tlio receiver 

 through the pipe b, and to have acted on the under side of the piston, so as 

 to give the same to the end of the stroke, at this moment the valve e will be 

 raised, so as to form a communication with the cductitn-pipe ^'' and tlie 

 cylinder, the lever or beam m being then raised, so as to elevate the cap A'' 

 the air from the cylinder will pass through the educlitn-pipe,?', and into the 

 cap/.-', which is supposed to be of about the same capacity as the cylinder- 

 On the return stroke of the piston, which we will no suppose to have arrived 

 at the bottom of the cylinder by the force of compressed air acting on its 

 upper surface, the eduction-valve e will be opened so as to form a communica- 

 tion with ihc peculiar/ormed jiump i ; by means of the pipeg-, the beam m is 

 again to be moved, so as to .depress the cap k', and raise the cap /.-, when a 

 similar effect tolhit already deicribed will be produced with regard to the 

 air contained in the cylinder on the top side of the piston, at the same time 

 the air from » ithin the cap /,' will be forced from thence into the receiver A, 

 and will be prevented returning by means of the valve /. " Hence it will be 

 observed, that, in accordance with the action of the piston, the caps /.■ /.' will 

 be made to reciprocate, and thereby draw off the volumes of condensed air 

 above and below, and force the columns of air, in their condensed slate, into 

 the receiver A, to be again passed through the pipe b into the cylinder, and 

 employed for keeping |up the continuous action of the piston, The lever »i 

 may (it is said) be elongated and connected, in the usual way, to the working 

 piston, and to this lever may also be attached the rod for working the slide- 

 valves. 



It has been'staled that the lever m may be worked by hand ; the speiifica- 

 tion here states, that, in some cases, it may be desirable to work it by power ; 

 for this purpose the inventor states that the lever m must be elongated, and 

 the piston of a small ste.im-engine may be attached to it, as shown at o, by 

 this means the vibrating action of the lever m shall be effected. 



Fig. 3 shews a section of a pipe, having a number of valves, which the 

 inventer proposes to employ for the eduction-pipes, the divisions in the pipe 

 he prefers to make somcw hat larger as they approach the cylinder ; the object 

 of this arrangement is to prevent the air returning from the receiver a. The 

 piston-ro.l. we ought to have observed, is connected to the cranks of the 

 driving, in the usual manner, and is intended to give motion to such wheels. 



The inventor claims first the mode of working engines and machinery by 

 me.ans of compressed air previously condensed, as ascribed and illustrated in 

 reference to fig. 1, however the engines, or other apparatus may he varied in 

 their constructive details, as long as the same system of action is preserved, 

 and the same elements are employed to produce it. 



Secondly,, the placing the purni)s and the apparatus within the receiver of 

 condensed air, for the purpose of prolonging and economising the woi king 

 power of the condensed air. 



Thirdly, the chamber or vessel i), fig. 1, for regulating the working force of 

 the condensed air drawn from the main receiver or receivers. 



Fourthly, the pipe, with a series of valves within it, wdiich may also Le 

 attached to immps and other apparatus. 



BORACIC ACID WOIIKS, MONTE CEHBOLI. 

 (From the Quarterly Journal of the Geological Society.) 



I cannot conctudi} this imperfect notice of the geology of Tuscany witliout cnlling atten- 

 tion 10 tlie borucic acid works at Rloute Ccrboli, and the remarkable phenomena there- 

 with connect&dj for I have no doubt but that many of the actual geological features of 

 Tuscany must be referred to agencies and to causes similar to those which are now exhi- 

 bited In this locality. 



The numerous and violent jets of vapour from which the horacic acid is extracted, rise, 

 with considerable noise and in large volumes, from a narrow rocky valley in the secondary 

 cretaceous liiiiestone, about 15 miles S. W. of Volterru. Huge blocks of this rock and its 

 associated indurated marls cover the surrounding hills, and add to the desolation of the 

 scen«. The vapour naturally leaves a considerable deposit; bat this Is much increased 

 in consecjucnce of its being compelled by artiUclal means to pass through water collected 



into numerous reservoirs. By this process, the water is Impregnateii with the loracFc: 

 add previously held in solution In tlievepour; while the greater part of the sulphur 

 lime, and carbonic acid gas, « hich it alto contaiiis, is deposited in the muddy bottoms of, 

 the pods, and assumes, when dry, u ciystKllinc form, being, from time to time, thro* n 

 out in the co'irse of the operations : sulphate and carbonate of llt^e arc also deposited Id 

 the cauhlroiis and cooling puns where the buraeic acid is obuined by eveporution fross 

 Itie saturated water. Amongst the neighbouring rocks, 1 saw a remarkable instance^ 

 where a large fissure or crack, with several smaller ramifications, hud been completely- 

 tilled up by the matter deposited by the vapour which must once have escaped through it. 

 The sides were coated with a hard compact calc-sinter, while the central portions were 

 filled with n more porous substance, so that ttie passage of the vapour had been obstructed 

 before the central parts had become so densely consolidated us ttie sides, thereby explain- 

 ing at least one of the causes by which these vents arc constantly changing their posilious, 

 and how tlie jets of v.:pour escape sometimes in one place and sometimes in another. 



Till-- simple mode by which the boracic acid is obtalnrd is us follows. Small reservoirs, 

 from l^ to 30 feet in diameter, are dug round the most convenient and powerful of the 

 many steam vents; and into these reservoirs a small stream of water is con''ucled from 

 the mountain side. After being for some time exposed to the acti.)n of the rising vapcur 

 Ihe water is let otf from one reservoir into anottier, until it has passed through live or six, 

 iti each of which it remains about '^A hours, the vapour bciling and bubbling up through 

 it the whole time with much noise and violence, lly this time iLe water is sufficiently 

 i'npref^nated with the borucic acid ; and after being allowed to settle in another reseivuir 

 to ueposil the mud. It is led oil' Into the evuporallug houses, wliere, after undergoing a 

 slow and gradual process of evaporation, the boracic acid is at length obtained in uu- 

 meroiis vats, where it crystallises with great facility. 



The great difbcnity formerly experienced in this process was the expense of fuel re- 

 quired for the process of evaporation ; until the happy idea at length suggested itself to 

 the proprietor of availing himself of the almost inexhaustible supply of heat prepareil by 

 Nature herself in the numerous vents from which the streams of boiling vapours wtrv 

 constantly emitted. Acting on this suggestion, he buiit a sort of chamber over some of 

 the vents, and conducting the vapour by subterranean channels into the evaporating 

 houses, obtained without a farthing of additional outlay ail the heat he could require. 

 The consequence of this simple application of natural power was, that the value of the 

 works rose, in one year, from a capital of one thousand pounds, for which the fee simple 

 was oITered, to a rental of twenty thousand pounds per annum. 



Similar vapours or " soffioni,*' as they are called, occur in several other localities iu the 

 same district, or within a distance of 12 or 14 miles, as ut Sarrezano. Custel Nuovo, Monte 

 Kotondo, and others ; and it Is impossible not to be struck with the manner In which 

 they throw light on many of the geological phenomena in this and other coin tries; parti- 

 cularly with regard to the tilling up of cracks and Ijssures in rocks, and the local deposits 

 of various substances, such as calc spar, gypsum, sulphate of lime, sulphate of soda, &c.y 

 many of which, occur i I this very neighbourhood. It is highly probable that such etnis- 

 sions of gases and vapours may have produced may of those local phenomena, which have 

 been so frequently atliibuted to the etlect of springs, and ate considered as aqueous de- 

 j,csits. That great connection exists between them cannot be doubled, as the soffioni of 

 Bloute Cerboli do unquestionably deposit much sulphate and carbonate of lime, and if 

 supposed to rise through water would most certainly deposit much more. On the whole, 

 therefore, whether we consider the remarkable and almost terrific appeaianc of these 

 vents, from Imndreds of which the vapours escape with the noise of a steam-boiler blow- 

 ing otf its steam, or the Importance they have iu connection with other geological pro- 

 blems to which they may ofi'er a solution, they must be considered as presenting to us 

 some of the most interesting, if not Im],ortnnt geological phenomena which the Tuscan 

 States can aSbrd to the pursuer of geological investigations. 



CO.\L FORMATION OF NOVA SCOTIA. 



By John Dawson. Esa. 



(From tlie Quarterly Journal o/ t/te Geological Society.) 



The carboniferous strata of this province may be included in three groups; first, the 

 gypsiferous or mountain limestone formation ; secondly, the older coal formation ; and 

 thirdly, the newer coal formation : of these the two former have almost exclusively at> 

 tracted the attention of geologists, the latter having been in a great measure neglected. 

 In connection with the Pictou coal field, however, and probably also in other parts of this 

 and the neighbouring colonies, the newer coal formation is an extensively distributed de- 

 posit, often attaining considerable thickness, and, though not containing valuable beds of 

 coal, ironstone, or gypsum, yet so associated with the rocks including these minerals, that 

 a knowledge of its structure and rt-latlons is essential to their satisfactory investigation. 



The coal measures of the Albion min. s, on the banks of the East River of Pictou, a 

 scries of beds, estimated by Mr. Logan at 5,000 feet in thickness, and constiluling our 

 older coal formation, are succeeded, in ascending order, by a great bed of coarse conglo- 

 merate, which, as it marks a violent interruption of the processes which had at cumulated 

 the great beds of coal, shale, and ironstone beneath, and as it is succeeded by rocks of a 

 character very ditferent from that of these older coal measures, forms a well-marked 

 bouudary, which we may consider as the commencement of the newer coal formation. 



In lithologieal character, the newer coal formation of Pictou strongly resembles the 

 lower carboniferous series ; the chief differences being that, in the former, llie beds of 

 grey sandstone are of greater comparative thickness, and that, in the latter, there are 

 great beds of gypsum and of limestone with marine shells. Our coal measures may thus, 

 in one point of view, be regarded as a subordinate group, included in a great thickness of 

 sandstones and shales, mostly of red colours. 



The sections which I have described are included in a district extending about fifty- 

 miles along the shores of the Gulf of St. Lawrance, from Merigomish to Wallace; form- 

 ing, I believe, the largest continuous tract of rocks of the newer coal formation In Nova 

 Scotia. 



Synopsis of the Carboniferous Rods of Pictou. 



1. ^fewer Coal Formation.— The prevailing rocks are alternately of reddish and grcf 

 sandstones and shales, with some coarse conglomerates, especially in the lower part. 

 Subordinate to these, arc dark grey concretionary limestone, thin beds of coarse sandy 

 limestone, two thin beds of coal and one of gypsum. Thickness, 6000 feet or more. 



Fossils.— Coniferous wood, Catamites, Jems., ^-c, Ganoid Jisli. Iracl;s of latxt 

 animals. 



2. Older Coal Formation.— The prevailing rocks are dark shale and clays, grey and 

 brown sandstones; and subordinate to these are coal, ironstone, dark limestone. Thick- 

 ness 5000 feet. 



Fossils. — Ferns, Sligmaria, Catamites, Lepidodendra. Sfc., Cypris. 



3. Itlountain Limestone, or Gypsiferous Formation.— The prevailing rocks are reddlab 

 sandstones, shales, and clays, with some grey beds ; conglomerates, especially in lowev 

 parts; and subordinate to these, thick beds of limestone, thick beds of gypsum with 

 onhydrite. Thickness, 6UU0 feet or more. 



F'ossii.s. — Catamilts, frai,menls of carbonized plants. Producia, Tercbralula, 

 Encrinites, Madrepores, iyc. 



