1848.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



S83 



sun, reddened liy a London fog, were exhibited 1)5' M. Claudet, which exem- 

 plified that fact in a remarkable manner, for the sun appeared as a hlaik 

 spot in a luminous sky. In an image of the solar spectrum the red rays 

 were black, the orange and yellow dark, and the brightest parts were tliose 

 iu the blue and \iolet bands of the spectrum, and in a space considerably 

 beyond the extent of luminous rays. Mr. Hunt announced that the results 

 of investigations in which be is still engaged lead him to the conclusion 

 that light has no part in the production of photographic pictures, and that 

 ill fact light obstructs the formation of such pictures instead of producing 

 them. In confirmation of this opinion, he stated that when attempting to 

 take the solar spectrum on photographic paper, all parts of the paper were 

 blackened excepting that whereon the spectrum fell, the paper on that part 

 having been protected from change by the action of light. 



Mineral Guano. — As the sources of animal guano becoire exhausted, 

 fresh supplies of that manure are discovered in the mineral kingdom, which 

 jKomise to last for ages. The discovery of a large bed of phosphate of lime 

 in Spain was two years ago considered an importdnt addition to agricultural 

 wealth, but since that time beds of phosphate of lime have been found much 

 more available, and Captain Ibbetson in a recent examination of the green 

 sand formation of the Isle of Wight has discovered a rich stratum of the 

 mineral manure, containing about 30 per cent, of jibosphate of lime. As this 

 is very accessible, it promises to become of great value, and there is no doubt 

 that similar stores of the phosphate may be be found iu other parts where 

 the greeii sand formation is situated. 



REGISTER OP tSESKT PATENTS. 



EXPANSIVE ROTARY STEAM-ENGINE. 



Robert Wilson, M. A., of Greenock, for " Improvtments in cer- 

 tain kinds of rotary steam-engines^ part of which improvements ore 

 applicable to rotary engines worked by water or by the wind ; also an 

 improvement in safety-valves fur steam-boilers." — Granted January 

 13; Enrolled July 13, 1848. 



The chief object of this invention is to introduce the princij)le 

 of working steam e.xpansively into rotary engines. This is proposed 

 to be effected by causing the steam which has first acted by impact 

 in one direction against the vanes of a wlieel, to operate again by 

 reaction in opposite directions in issuing out of the intervals 

 between the vanes. The figure re])resents a side elevation of an 

 engine constructed according to this part of the invention, and 



Laving one-half oftheeovei or side removed, in order to exhibit 

 the internal construction. The circular case is rendered steam- 

 tight, and has an entrance-passage at I, for the steam. Tliere is 

 also an eduction-passage at K, through which tlie i~teiim in an 

 expanded state is allowed to pass away into tlie air, or else into a 

 condenser ; and although the induction-passage k appears very 

 near to the entrance-passage I, yet the steam does not pass directly 

 to K, but passes nearly all round within the case, in order to imjie'l 

 the vanes g g, by acting over and over again with more and more 

 expansive action at several different places around, within the 

 circumference of the case, in succession, before the steam arrives 

 in a very expanded state at the eduction-passage K. In addition 



to the curved vanes g g, there are other curved vanes r r, fixed 

 within chambers n »/, which the patentee calls reversing-chambers, 

 and which with the said fixed vanes are for giving to the current 

 of steam the directions in which it is to act over and over again 

 against and between the curved vanes g g, of the wheel. Some of 

 the reversing-chambers are disposed in an outer circle m m, which 

 are also furnished with stationary vanes r r ; the moving vanes g g, 

 therefore revolve between two separate circles of fixed vanes. All 

 these vanes being truly arranged in their several circular rows, 

 with the edges of the vanes in conformity therewith, tlie interior 

 edges of the fixed vanes in m m, and the exterior edges of the 

 vanes r r, in the chambers n r?, are close to the edges of the moving 

 vanes g g : but at no part of its circumference is it allowed to touch 

 or come in contact with the fixed vanes r r. In order to give 

 firmness to the vanes, which are made of thin metal plate, they are 

 united by means of flat circular rings, which are as close as possible 

 to the moving parts without actually touching. The effect of these 

 rings is not only to strengthen the vanes, but also to subdivide the 

 whole of the passages into narrow semicircular courses, in order to 

 direct the currents of steam. The steam from the boiler enters 

 the case at I, and is first directed into a curved course at ?», which 

 is divided into three spaces in order to compel the steam to proceed 

 in three currents towards the axis of the wheel ; but owing to the 

 curvature of the vanes, the three currents of steam, when they are 

 passing out from those spaces, are caused to assume nearly the 

 direction of tangents to the semicircular curvature of the moving 

 vanes g g, against which the steam will first make its impact by 

 acting against the concave sides, which deflect or turn the course 

 of the steam which now issues from the spaces between the vanes 

 g g, at the interior circumference, and is received into the chamber 

 n', when the direction again becomes reversed owing to the semi- 

 circular curvature of tlie boundary of that chamber, so that the 

 steam will be turned towards the vanes </ ^, proceeding in a tan- 

 gential direction to the wheel in order to act again on tlie vanes g y, 

 by impact. The steam, permitted to expand whilst in the reversing 

 chamber n", in its second impact w ill, therefore, be in an expanded 

 state, and will enter into a greater number of spaces between the 

 vanes g g, exerting a re-action in so issuing, when it is again re- 

 ceived into another reversing-chamber >?;■', wherein the steam is 

 still further expanded, and becomes again reversed in its direction 

 to the chamber m^, from which it passes as before to chamber n", 

 where it is still further expanded, reversed, and divided into 

 numerous streams continuing a similar course through the different 

 chambers m", n", m', it", and so on throughout the circumference, 

 being proportionately expanded in each chamber till at last it 

 escapes through the eduction-passage K. By the continual impact 

 and reaction of the steam, a rapid rotary motion is communicated 

 to the wheel. Another part of this invention relates to improve- 

 ments in rotary-engines of impact, the object of which being to 

 combine together two revolving w heels, having curved vanes affixed 

 to the wheels, in circular rows in a very similar manner to the 

 vanes y g, already described, but the circular row of vanes is larger 

 than on the other wheel, so that one circular row is surrounded by 

 the other. These two wheels are inclosed within a case, the vanes 

 iu the one being reversed to that of the other. The current of 

 steam which lias passed through the curved spaces between the 

 vanes of one wheel, and has changed its direction in so doing, will 

 enter into the curved spaces between the vanes of the other wheel ; 

 and the steam in so doing will act by impact and reaction to turn 

 both wheels round, but in contrary directions of rotation. The 

 fourth improvement relates to rotary-engines to be worked by 

 water or w iiid, the mode of action being by impact and by re-action. 

 They are arranged in a similar manner to the last described. The 

 fifth and last part of these improvements relates to safety-valves 

 for steam-boilers, which the patentee constructs with columns of 

 mercury contained with a cluster of numerous tubes of iron or glass 

 disposed side by side, the passages through which tubes are kept 

 effectually stopped by having the orifices at their lower ends im- 

 mersed to diflercnt levels beneath the surface of mercury, contained 

 in a cistern to w liich the steam has admission. The mercury will 

 effectually prevent any escape of steam, so long as the pressure is 

 no greater than intended. But if the pressure of the steam depress 

 the level of the mercury below the lower end of one of the tubes, 

 then the steam will force its way up that tube; and if the steam 

 still increases iu pressure, the surface is depressed still lower, sous 

 to get below the level of the low er end of another tube, and so on ; 

 more of the tubes will become opened, one after another, as the 

 pressure may require. 



