1844. 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



275 



hausted of air and steam. It consists of a longer and a sliorter tube of iron, 

 both of one diameter and truly bored, and joined together, at bottom, by a 

 bent iron pipe. It should be fixed up perpendicularly, and should be filled 

 with mercury until it stands eighteen inches deep in the shorter or open leg ; 

 a light float of wood, something like a gun-rammer, should be put into the 

 short leg. and cut off even with the top of the scale when the engme is at 

 rest, and the eduction pipe filled with air. The scale is divided into half 

 inches, which correspond to inches on the common barometer, because for 

 every half inch the mercury rises in the long leg, it falls half an inch in the 

 short leg, which, added together, make one inch diflerenci- of height. A pipe 

 from the top of the long leg is joined to the eduction pipe, below the blowing 

 valve ; for were it fi.\ed higher, steam might come through it and loosen the 

 cement, which connects the pipe and the barometer. M'hen the mercury in 

 the common barometer stands at thirty inches, it should stand at twenty- 

 eight and a half inches in this barometer, providing your engine be in good 

 order ; and at proportionate heights at other states of the atmosphere. — The 

 steam guage is a similar instrument, in which the steam presses up a column 

 of mercury, proportioned to its elasticity. When the engine is underloaded, 

 it ought to be wrought with steam able to support one inch of mercury ; and 

 when fully loaded, it ought not to esceed two inches ; but if the engine be 

 loaded to more thin ten pounds and a half on the square inch of the piston, 

 the strength of the steam must be increased accordingly. — It is never advis- 

 able to work with a strong steam where it can he avoided, as it increases the 

 leakages of the boiler and joints of the steam case, and answers no good 

 end. 



58. A very important article is the proper packing of the piston, directions 

 for which have already been given. (.See Section 46.) 



59. The buckets of the hot water and air pumps must be packed with a flat 

 rope, wrapt round them edgeways ; and the ends of these gaskets must be 

 made fast by being drawn through holes made in the buckets for that pur- 

 pose ; and secured there by wooden pegs, hard drove in. The gaskets should 

 be well smeared with tallow, before the buckets are put in ; and they should 

 not fit the pumps too tight ; as their sticking is very troublesome, especially 

 at first. — The stuffing boxes ot the cylinder and air pump must be packed, by 

 wrapping a soft rope round the rod, and beating it until it nearly fills the 

 stuffing box, remembering to soak it well with tallow, as you go on. Above 

 this rope lay on the wooden collar, and screw the gland down upon it mode- 

 rately tight. 



60. To set the engine to work, raise the steam in the boiler until the index 

 of the steam guage is at three inches on the scale. When the outer cylinder 

 is fully warmed, and the steam issues freely on opening the small valve at the 

 tottora of the syphon, or waste pi|ie, which discharges the condensed water 

 from the outer bottoms, open all the regulators. The steam will then forcibly 

 blow out the air, or water, contained in the eduction pipe by the blowing 

 valve; but cannot immediately take place of the air in the cylinder itself 

 To get quit of it, after you have blown the engine a few minutes, shut the 

 steam regulator. The cold water of the condenser cistern will condense some 

 of the steam contained in the eduction pipe, and its place will be supplied by 

 some of the air from the cylinder. Open the steam regulator, and blow out 

 that air. and repeat the operation, until you judge the cylinder to be clear of 

 air. When that is the case, shut all the regulators, and observ e if the baro- 

 meter shows that there is any vacuum in the eduction pipe. When the 

 barometer guage has sunk three inches, open the injection a very little, and 

 shut it again immediately ; if this produces any considerable degree of 



. vacuum, open the exhaustion regulator a very little way, and the injection at 

 the same time. If the engine does not commence its motion, it must be blown 

 again, and the same operation repeated, until it does move. If the engine 

 he very lightly loaded, or if there be no water in the pumps, you must be 

 very nimble, and quickly shut the exhaustion and top regulators, so soon as 

 it begins to move ; otherwise, it will make its stroke with great violence, and 

 perhaps do some mischief. To prevent which, open the top and exhaustion 

 regulators only a little way, and put pegs in the plug-tree, so th at they may 

 be sure to shut these regulators long before the piston gets to the bottom. — 

 If there is much unbalanced weight on the pump end, you mu st also take 

 care to put a peg in the ladder which guards the steam regulato r lever, so as 

 to allow that regulator only to open a little way, and so to lessen th e pas- 

 sage for the steam, when it enters to fill the cylinder ; otherwise the rods, 

 &c , at the pump end may descend too fast and be prejudicial. If you find, 

 after a few strokes, that the engine goes out too slow, the steam regulator 

 may be opened wider. In order to regulate the opening of the exhaustion 

 regulator, you should have pieces of board of various thicknesses to put 

 under the weight which pulls it open, by means of which it may be made to 

 open more or less at pleasure, and the top regulator may be managed in the 

 some manner. 



61. Should the engine work with too great violence on account of its being 

 underloided, you may correct it by giving the top regulator a lesser open- 

 ing, and shutting it at such part of the stroke as will give the piston suffi- 

 cient force to come to the bottom. Whenever the top regulator is used, the 

 exhaustion regulator should be thrown fully open at every stroke, in order to 



give a free c.\it to the steam, on which a great part of the good effecls of ihe 

 top regulator depends. — The engine should always be made to work full 

 stroke.— that is, until the catch-pins come within half an inch of the springs 

 on each end, which is easily managed by an attention to the pegs. Care 

 must be taken that the piston rise high enough in the cylinder when the 

 engine is at rest, to spill over into the perpendicular steam pipe any water 

 which may be conilensed above it ; for if any water remain there, or in any 

 other part of the cylinder while it is working, it will very much increase the 

 consumption of steam. When the engine is to be stopped, shut the injection 

 and secure it ; put a [x^g in the plug. tree to prevent the exhaustion regulator 

 from opening, and take out the peg on ihe other side, so as to allow the 

 steam regulator to open, and to remain open ; otherwise you may have a 

 partial vacuum in the cylinder, and it may be filled with water from the in- 

 jection or leakages, wliicli will be a troublesome accident. The top regulator 

 must also be open while the engine is at rest. — When an engine is in toler- 

 ably good order, it will bear to stand ten minutes, and go to work again 

 without blowing afresh, and though it has stood two or three hours, if there 

 has been any steam issuing from the boiler, and no air has been admitted 

 into the cylinder, it will generally go off, with once blowing for about a 

 minute. 



62. If you find, after following the above directions, that the engine does 

 not go to work, shut the exhaustion regulator, and give some injection ; if it 

 then makes no vacuum, it is likely there are air leaks about the eduction 

 pipe ; if it does make a vacuum, which remains but a short lime, it may be 

 owing either to air or water leaks. These may be distinguished, by blowing 

 as before, and shutting Ihe lower regulator for about a minute, without 

 giving any injection. If upon o[X<ning it again, it throws out a good deal ot 

 water at the blowing pipe, before it blows steam, it is certain it either has 

 some leak in the condenser under water, or that the injeclicn or blowing 

 valve does not shut close ; if they are found to shut close, every joint should 

 be examined, and also the valve at the foot of the eduction pipe. — If after 

 blowing as before, you find tiiat immediately on opening the exhaustion re- 

 gulator, a quantity of air is thrown out at the blowing valve, the leak is in 

 the eduction pipe, somewhere between the surface of the water in the cistern 

 and the nozzle. The particular place of these leaks may be found by empty- 

 ing the cistern of water, putting three or four feet deep of water into the hot 

 water pump, and staking down the blowing and injection valves with those 

 on the air pump lid; then if steam be admitted into the duction pipe, it will 

 come out at the leaks and point them out. If not found in this way. apply 

 the brake to the air pump, taking care first to put some water on its bucket 

 and then by working that pump hard, you will probably, on an attentive 

 examination, observe where air goes in, which may be known more distinctly 

 by wetting the place suspected.— If upon shutting the lower regulator, and 

 making a vacuum in Ihe exhaustion pipe by pumping, or by injection, you 

 find that vacuum continues good for a considerable time, then the fault does 

 not lie in the eduction pipe, but in the nozzle or joint of the cylinder bottom, 

 where it must be sought for. — In these examinations, by pumping, it is pro- 

 per to take oft' the bonnet, or cover of the exhaustion regulator, and to ex- 

 amine if air enters at that regulator : if it does, and only in small quantity, 

 throw some water on the regulator while you are examining the eduction pipe. 

 When the leak is suspected to be in the bottom joint of the cylinder or in 

 the lower nozzle, you must throw some w.ater on the steam regulator and 

 also on the piston, then by pumping and strict examination, you will find 

 where the air enters. When you are examining the tightness of the piston, 

 by pumping, you must stake the beam, so that the piston may not descend. 



63. If in course of working, you do not find the vacuum keep good, and 

 the engine goes sluggishly, or stops and requires to he blowed through fre- 

 quently, you must examine whether an uncommon quantity of air or water 

 issues at the hot water pump, or if any comes out at the valves on the ait 

 pump lid; if the quantity of air is great, the engine has some air leak, and 

 if the quantity of water be great, and is rather cooler than usual, it proceeds 

 from a water leak in the condenser ; if the quantityof water be great, and at 

 the same lime very hot, it proceeds from a bad piston, or from the steam re- 

 gulator not shutting close. — The engine will also w ork badly, if the air pump 

 or water pump buckets, or clacks, slip the water ; Ihat is let it pass by thera ; 

 you will know if this be the case, with the water pump bucket, by observing 

 w hether the water follows down after it at the return of the s'roke, and leaves 

 a part of the pump empty ; if it does not, either the bucket slips the water, 

 or the engine receives water in some way which it ought not. 



64. Attention ought to be given to feeding the boiler in a regular manner, 

 that it may not be spoiled, nor steam be wanted. When there is too much 

 water in the boiler, the engine will not work regularly ; and if there is too 

 httle, the sides of the boiler will be burnt by the flame in the flues. If by 

 accident it should at any time run a little too low, the feed should be aug- 

 mented, so as to fill it gradually ; for if you run in too much at once, you 

 will check the steam and stop the engine ; but if it be run very low, stop the 

 engine, open the puppet clack, and fill the boiler from the pool, or reser- 

 voir, if you have one, otherwise fill it by working the air pump ; having first 

 staked down the valve on its cover, and opened the injection valve. In work- 



