THE CIVIL ENGINEER AND ARCHITECPS JOURNAL. 



[AURUST, 



and rest in the side walls ; b b b show a number of joists which are 

 supported by the flanges of the cast iron beams as will be clearly 

 seen; upon these joists is laid about f of an inch thick of plaster com- 

 posed of one part lime and three parts coal ashes, which, says the in- 



Fig. I. 



h/' 



y\ 



i 



mm [(P!^li3!llPl <^ 



ventor, pressing through from between the " laths" or joists, serves as 

 a key to hold the ceiling; upon this composition is then laid a mix- 

 ture of eight-tenths of road grit, one-tenth of coal ashes, and the same 

 quantity of lime mixed with water ; this mixture, which the inventor 

 calls pugging, should be hud on about the " thickness shown in the 

 drawing," which is about -j^ of an inch, and the same well trodden ; 

 the specification does not show what is to support this mixture in the 

 spaces between the joists, as atec, but goes on to state that this latter 

 surface is to be covered with a cement consisting of one part lime and 

 two parts coarse sand, which surface is to be trowelled quite flat, and 

 when the same is perfectly dry, it is to have about two coats of cold 

 drawn linseed oil, made quite hot and laid on with a brush similar to 

 those used by whitewashers, which when dry is said to make a very 

 tough floor, and one not liable to be injured by cleaning or removing 

 furniture. 



The fire-proof ceiling is to be made with the above compositions 

 and plastered in the ordinary manner. 



The only difference between the fire-proof roof and the floor is that 

 it will be necessary to give a slight inclination to the roof in order 

 that the water may get off, and also that the " iloating" should be done 

 with air mortar instead of the ingredients above described, and the 

 coatings of linseed oil omitted, the roof being covered with pitch, 

 paper, and sand in the following manner. Take 12 gals, of mineral 

 tar and boil it down to 9 gals., the process of boiling should be done 

 with care, and in such manner that the tar shall have acquired a pro- 

 per consistency and adhesive quality, the roof is then to be covered 

 with the tar in a hot state, and then covered with paper, one side of 

 which is to be covered with raw tar, after the paper has been laid 

 down with the tarred side downwards, this paper covering is then to 

 be covered with hot tar and immediately covered with fine gravel 

 freed from earthy matter, which completes the process of constructing 

 fire-proof roofs according to the specification. 



SCREW PROPELLER. 



or "im- 

 Enrolled 



Bennet Woodcroft, of Manchester, consulting engineer, f 

 provements in propelling vessels." — Granted February 13; 

 August 13, 1844. 



This invention consists in a mode of arranging the floats of screw 

 propellers, whereby they may be placed at an angle forming a screw 

 of any pitch, from 7j feet to 14J feet ; and by which arrangement the 

 speed of the vessel may be increased or diminished at pleasure, and 

 also in an apparatus for indicating the angle or pitch at which the 

 lats are set. Fig. 1, shows a side elevation of this apparatus, which 



Sxed iu the dead wood of the vessel, A being the stern post, and B 

 P^''"ieel ; c, c, is a cast iron frame supporting the shaft d, upon which 

 ■^' iy keyed, a boss ei' having four projections e, e, e, of a peculiar 

 moved ,j ^^ constructed as to carry the vanes or floats/,/;/, and allow 

 ^'°mi • urning upon their axis so as to form any desired angle with 



The inv gjj^ff. g^ jg ^ jj^g^ ^^ ferule which is made to slide end- 



*^"S^"'.*/'° he shaft, the same being prevented moving round upon 



nally with tli^, j^Q fixed keys or feathers j, upon which the boss or 



the form ot p , loosgiy, j^ the periphery of this boss there are four 



nly of which is seen in the drawingi these grooves re- 



ceive four studs which are fixed to the arms or levers /, /, I, the oppo- 

 site end of these arms pass through a slot formed in the projections 

 e, e, e, and are attached to the axis of the vanes or floats. It will 

 Fig. 1. Fig. 2. 



therefore be evident from tlie above that by sliding the boss back- 

 wards or forwards upon the shaft, that the angle of the floats may be 

 varied, and the speed of the vessel increased or diminished as may be 

 required. This sliding motion of the boss g, is effected as follows : 

 m, is a bracket or support bolted to the stern post of the vessel, this 

 bracket supports the axis n, of two bell cranked levers, one being at 

 each side of the bracket ; at the lower end of these levers there is a 

 stud which fits loosely in the groove o, at the opposite end of these 

 bell cranked levers there is attached a rod p, having a screw cut upon 

 it, which passes through a nut 5, fixed in the deck of the vessel; r, is 

 a wheel fixed to the top of the rod p, and having a number of handles 

 on its periphery, by turning which the rod will be raised or lowered, 

 and consequently the bell cranked lever; s, is a lever moving upon an 

 axis, one end of which forms a toothed sector, working in a rack at- 

 tached to the screw rod p, the opposite end of the lever s, moves over 

 a graduated plate, and indicates the angle or pitch at which the floats 

 are set. 



CHAINS FOR IVnNING, 



Job Haines, of Tipton, in the county of Stafford, coal master, and 

 Richard Haines, of the same place, coal merchant, for " an improved 

 method or methods of making or manufacturing links for the construction 

 of flat chains used for mining and other purposes." — Granted February 

 13 ; Enrolled August 13, 1844. 



This invention for improvements in the construction of flat chains 

 for mining and other purposes, relates not only to the mode of manu- 

 facturing of flat chains for the purposes above described, but also to 

 the peculiar form or configuration thereof. The links of these chains 

 vhich are made from flat bar iron in the manner hereafter described 



