SOS 



THE CIVIL ENGINEER AND ARCHITECTS JOURNAL. 



[November, 



Maudsbys & Co. are in the habit of making their journals with very 

 large fillets in the corners, so as, in fact, to make eacli end of the 

 journal a short frustrum of a cone. This has the desired effect, but 

 occasions a wasteful expenditure of the oil. Mr. Robert Napier 

 makes his cranks to bear against the flanges of his brasses. This plan 

 obviates the rapid wear, but still leaves any wear that has taken place 

 unsusceptible of re-adjustment. The best plan, it appears to us, 

 would be to make each journal bulge out in the middle, so as to con- 

 stitute, in fact, a portion of a spheroid, and recess each brass corres- 

 pondingly. The act of tightening the top screws of the journal would 

 then have the effect of preventing the shafts from moving on end, as 

 well as of preventing them from moving up and down. The outer 

 bearing of the paddle shaft should be always so made as to admit of 

 easy adjustment. A common plummer block with the top constructed 

 for holding tallow, placed upon a good stout carriage bolted to the 

 fore and aft bearers, is, in our judgment, the best arrangement. The 

 plummer block bolts should be so made that they may be dropped 

 down to admit a piece of plate iron between the sole and the carriage 

 at any time the shafts may require re-adjustment. A brass in the 

 upper part of the plummer block at the outer end of the shaft is un- 

 necessary, as there is no upward strain, and the cover bolts should be 

 merely sufficient for holding it on in a sea way. This journal always 

 wears forwards as well as downwards, and the brass should be so 

 made as to admit of the aftermost side being turned before. The 

 sides of the brass should also be thicker than in journals where this 

 action does not exist. 



Pisston Rods. — The best mode of attaching the piston rod to the 

 cross head is by means of a cone and cutter and gib, and a screw 

 above the cone; this cone should have considerable taper both to 

 obviate any injurious expanding action which a cone of little taper 

 would occasion, and to facilitate the disengagement of the rod when 

 it requires to be taken out. Some of Boulton and Watt's cross heads 

 are made close over the piston rod, except that a little hole is left in 

 the top to admit the introduction of a drift to start the piston rod 

 when it requires to be disengaged. This we think is a very objec- 

 tionable plan, and we have known it in practice to be productive of 

 the most serious inconvenience ; for a small drift will not start a rod 

 on which the taper is not considerable, and which is rusted into its 

 place. The drift may indeed be assisted by a cutter driven into the 

 cutter-hole, and so contrived as to force the rod down instead of 

 keeping it up; but even with this aid we have known the largest drift 

 that could be introduced through the top hole to be quite ineffectual 

 in starting the rod. It is a bad practice too to make the upper part 

 of the rod that fits in the cross head eye parallel ; a blow or two upon 

 this parallel part will stand and swell it so as to rivet the rod into the 

 socket. 



Iron Ships have been much cried up of late by iron ship builders. 

 We admit their claims to favourable consideration, but at the same 

 time maintain that they are attended by many serious disadvantages. 

 In the first place the accumulation of sea weeds and barnacles is a 

 formidable objection. We have seen indeed a scheme of a scraper for 

 removing these accumulations whilst the vessel was under weigh, but 

 it is in our mind puerile aud impracticable. Again, the iron of which 

 vessels is composed has been found to become brittle in the course of 

 years, so that although tough at first, it will in the course of time star 

 like glass when struck by a hard and sharp body. The action appears 

 analagous to that which takes place in railway axles. Mr. Nasmyth, 

 indeed, has shown that railway axles are rendered brittle by cold 

 hammering, and maybe toughened again by annealing; but he has 

 not shown that axles are not rendered brittle also by continued wear, 

 or that this species of brittleness admits of the same remedy. 



Bilge Pipes are best of lead, both because lead resists the action of 

 the bilge water better than any other metal and because it is much 

 cheaper than copper, but the blow off pipes should never be of 

 lead ; lead blow off pipes bulge and burst from the continued heat and 

 fragrance to whicl: they are subjected. We find that Mr. P. Taylor 

 at the Institution of Civil Engineers, a short time ago recommended 

 all the pipes exposed to the action of the bilge water in any measure 



to be of lead, and his recommendation was allowed to pass without 

 comment. We therefore think it expedient to say that we altogether 

 differ from Mr. Taylor in this particular. Neither the blow off or 

 deck pump pipes should ever be of lead though they are always more 

 or less exposed to the action of the bilge water. No engineer in this 

 country ever thinks of making blow off deck pump, or injection, pipes 

 of anything but copper. 



jraslc Sltam Pipe shou'.d be as high as the funnel, especially if 

 situated before the funnel. When the waste steam pipe is shorter 

 than the funnel, the action of the steam on the iron of the funnel 

 rapidly oxidizes it and speedily makes the funnel very thin in that 

 part of the ascent to the mouth of the waste steam pipe. When the 

 pipe is made as taunt as the funnel the steam is carried clear of the 

 funnel altogether. 



Slop ralvts bebceen the boilers should be permitted always to act of 

 their own accord, and should never be opened and kept open by 

 drawing up the spindle and keeping it up. Unless the stop valves be 

 allowed to act spontaneously like the safety valves, they will soon 

 become so fixed by corrosion that they cannot be shut at all, and are 

 consequently of no avail. If the increased pressure incident to the 

 weight of the valve be objected to, that weight may easily be ba- 

 lanced by a weight and lever attached to the spindle, where it emerges 

 from the stuffing bos of the valve box cover. 



Rudder. It is a judicious practice to make the rudder rather 

 shorter than is requisite to reach the keel— the rudder will thus be 

 unaffected if the vessel takes the ground. The keel should always 

 project a little beyond the rudder joint so as to prevent warps or 

 ropes of any kind from catching in the joint as the vessel passes over 

 them. The rule joint is the best species of joint for a steam packet 

 rudder, and bv far the neatest : the rudder head should be round and 

 should fit accurately in the rudder trunk, which of course should be a 



cylinder. 



" Paddle box boals of Capt. Smith are we think inconvenient— un- 

 sightly and ineligible. It would be greatly preferable to have a dozen 

 boats stowed inside one another like the nests of pill boxes of the 

 apothecary. In a heavy sea the paddle box boats could not be raised 

 without great difficulty, and when raised could scarcely be ap- 

 proached. Their proximity to the paddle when launched is dan- 

 gerous, and the waves would fly up through the paddle box in a sea 

 way with great force, and cut off all communication between the boat 

 and the ship. We regret that Capt. Smith has not found a better 

 vehicle for his ingenuity than this cumbrous, ineffectual and unsailor- 

 like contrivance. 



CANDIDUS'S NOTE-BOOK. 



FASCICULUS XLII. 



" I must have liberty 

 M^itlial, as large a charter as the winds, 

 To blow on whom ] please." 



I. Mr. G. R. Lewis' notions in regard to " intelligence of design" 

 and symbolical expression in ecclesiastical architectures, are too tran- 

 scendental, not to say, whimsical, to be adopted by our modern church 

 builders, and perhaps it is well that such is the case, since the fanciful 

 myiiticism which he recommends might lead to conceits that had 

 better be avoided, ambiguous at the best, and occasionally susceptible 

 of very sinister interpretations. A very great deal of symbolical 

 meaning, whether intended or not, shows itself, for instance, in the 

 design of Bernini's celebrated bronze baldachino in St. Peter's, al- 

 though critics who look no further than their noses have never detected 

 it. Many of them have reproached the artist for his bad taste in 

 making the shafts of the columns tmsled, and as far as mere external 

 form goes, they are right ; but then they quite overlook the mystic 

 meaning couched under that form. Those columns wind themselves 

 in folds like so many huge serpents, rearing their heads aloft, and 

 thereby typify, in the most expressive manner, both the sfrpenl-like 



