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WRINKLES
AND ^'^i'Y tk
RECIPES,
COMPILED PROM THE
Scientific American.
A Collection of Practical Suggestions, Processes, and Directions lor
THE MECHANIC,
THE ENGINEER,
THE FARMER, and
THE HOUSEKEEPER.
I1L.1L, u©tiia.tje:i>.
EDITED BT
p ^??^ Pi iv B E jsr J A Tvi I ]sr.
Revisers and ContriMors :
Professor R. H. THURSTON, C.E.
Professor P. H. VANDER TTEYDE, M.D.
RICHARD H. BUEL, Mechanical Engineer.
JOSHUA ROSE, Mechanical Engineer.
Xeav-York ;
TI. ?^. IVrXJNINr, FXJBLISHER, 3r Park Row.
Entered according to Act of Congress, in the year 1875, by
H. N. MUNN AND PARK BENJAMIN, in the Office of the T.ihrnrian of Congress, at Washington.
THEGEnYCENlER LIBRARY
If any worker in five great army of those in, whose intelligent labor lies the surest foundation for the prosperity of us all, finds among the sug- gestions here compiled one tJvought, as it is hoped he may many, ivhich shall lighten his toil or aid him in the production of better work, then the editor sincerely trusts that that worker will deem this little volume as prepared, for his es- pecial benefit, and to him especially dedicated.
PREFACE.
The aim iu the following pages has been to compile a collec- tion of suggestions for the every-day use of the workiug-man,in his shop, about his dwelling, or in his household. The book is not an encyclopaedia of recipes, nor does it make any pretensions to that title ; on the contrary, a very large number of formulae have purposely been omitted, because they are, for the most part, at- tainable in other and more extensive works. Preference has been given to practical hints, and, while the majority of these have been carefully gathered and condensed from the back files of the Scientific American, and more especially from the letters of cor- respondents of that paper, a goodly proportion are entirely new and fresh, and have been prepared expressly for this book.
For the contribution of a large part of the matter in, and for the general supervision of the department of Mechanics, the edi- tor is indebted to that thorough workman, Mr. Joshua Rose. To Mr. Richard H. Buel (whose articles are signed " B.") similar ac- knowledgments are owing for valuable papers on boilers, engines, and other to|)ics in the department of Engineering. The general revision of the last-mentioned department has been the labor of Professor R. H. Thurston, of the Stevens Institute, as has the si- milar overlooking of the department of Technology, that of Pro- fessor P. H. Van der Weyde. To both of these distinguished gentlemen, as well as to Messrs. Munn & Co., the publishers of the Scientific American, who have most kindly afforded the facili- ties for the preparation of this work, the cordial acknowledgments of the editor are due.
New-Yokk, 1877.
CONTENTS,
*
*
Subjects will he found arranged nlphahetically under the
below-indexed subheadings of the various departments.
Mechanics: p^ge
Master Tools and their Uses 7
Tools 16
Mechanical Shop Wrinkles and Directions . 38
Engineering:
Testing Materials 55
The Engine and its Appendages 57
The Boiler and its Attachments 87
Belts, Pulleys, and Sliafting 109
Practical Technology :
Cements, Glues, and Moulding Compositions 135
Metal-Working Hints and Kecipes 140
Simple Instrunii'uts and their Uses 150
Recipes for the Preparation of wood 156
The Preservation and Preparation of Natural History Specimens 158
Painting, Ciilding, and Varnishing Recipes 166
Hints about Drawing and Sketching 171
Simi)le (lalvanic Batteries and Electroplating Recipes. . . .178
Useful Chemical Recipes for Detection of Adulterations, etc 181
The Farm :
Farm Buildings 189
The Dairy 202
Farm Hints and Reciiies 204
Household Hints 223
MECHANICS.
MASTER-TOOLS > THEIR MANUFACTURE AND
USE.
The master-tools, here illustrated and described, comprise all that are necessary for plain machine- work in every description of metal ; and if they are made of the precise shape, and according to the given instructions, they will perform the full amount of duty here allotted to them, which, though it may appear to be unusually great, may be thoroughly relied upon for metal of any ordinary degree of hardness. Xor can any less amount of duty be obtained from them without evidencing inferior mechanical skill either in making or using the tool. It is true economy to ob- tain from a cutting tool its utmost amount of duty, which, though it may entail a little more drawing out and grinding of the tool in a given time, does not involve anymore as compared to the quantity of work performed. It is well within the mark to say that at least one third more duty, in a given time, may be ob- tained from cutting-tools for metals (used in all machines having variable speeds and feeds, such as the lathe and the shaping- machine), than is obtained in the usual practice of our machine- shops, especially in the larger ones.
Boring-tool for Brass. — The boring tool for brass-work, here shown, is a standard tool for either roughing out or finish-
BORING-TOOL FOR BRASS.
ing, both of which duties it will perform equally well. It is bent further round at the end than is the boring-tool for wrought-iron, to prevent it from jarring or chattering. It is a master-tool in ev^ery sense of the word. It should be hardened right out, and used with a quick speed and light feed, no matter how deep the
8
MECHANICS.
cut is. To prevent chattering or jarring when extending far out from the tool-post, or when it is very slight in body, it should have the toi) face depressed toward the cutting edge. When this tool is a stout one, the point may be ground more round, which will make it cut to finer finish.
BoHiNG-TOOL KOH Wrought-iron OR Steel. — For turning Out small holes, the tool here represented has no equal, providing it
BORING-TOOI, FOR WROl'ClIT-IltON OH STEEL.
be made of the precise shape shown, the reasons for which are as follows : The cutting end must not be bent, in forging, any fur- ther round, because, in that case, the strain placed upon the tool by the cut will be in a direction tending to revolve the tool in the tool-post, giving the tool a corresponding tendency to spring away from its cut ; and further, because so stout a tool could not be got into the same size of hole. The degree of bend or angle of the centre-line of the bent end to the centre-line of the length of the body of the tool, causes the strain of the cut to be placed comparatively endwise of the tool, endeavoring to force it back into the tool-post, and thus ])lac('s flic strain in the direction in which the tool is best caiJabU; of withstanding it. The keenness and shape given to the top face of the tool make the cutting edge perform its duty on the front edge, which again tends to place the strain endwise on the tool, operating, by the strain on the top face of the tool (caused by its bending tlie sliaviiig), to keep the tool to its cut by giving it an inclination to fct-d itself forward, thus rclifving tho feed-screw and nut of tlie slide-rest of a part of tlie duty of f.-eding. The cutting edge should not, even when tlie too] is newly forged, stand much, if any, above the horizontal ydane of the top of the body of the tofd, otlierwise so stout a tool can not be got into a given size of hole, a consideration which is f)f the utujost importance ; because boring-tools, from their com- parative slightness, especially in lotii: holes, are a|)t, under the most favorable of conditions, to spring away from the cut as the cutting proceeds toward tlie back end of the hole, thus making the latter a tajier, of Avliich thi^ back end has the smalli'st diame- ter, necessitating neveiiil line finishing cuts in order to mak«^ a parallel hole. If, however, <'very means is taken to use as stout a tool as the size of tlie liole will admit, the boring-tool will bore u very true and smooth hole.
MECHANICS.
9
In using these tools, it is best to employ a comparatively quick speed and lio^bt feed, no matter what the depth of the cut may be. They should be tempered to a very light straw if the tool is slight, and otherwise hardened right out ; and the work should be freely supplied with soapy water. For use on copper, the top face should be ground more hollow, so that the cutting edge will be much more keen than is here shown. Whenever there is sutficient room in the hole, a stout bar of iron or steel should be held in the tool-post, and a short tool secured by set-screw in the end of the bar, thus securing greater rigidity than is pos- sessed by a boring-tool, and facilitating the forging and grinding of the cutting-tool
Finishing-Tool for Cast-Iron. — Cast-iron may be finished true and smoothly by a tool having a much broader cutting and scraping surface than is applicable to any other metal ; and we are therefore enabled to apply to it, for finishing purposes, the
FINISHING-TOOL FOR CAST-ERON.
tool above illustrated, setting it so that its square nose is placed quite parallel with the work, and feeding it with a feed almost as coarse as the width of the square nose, say 8 revolutions of the lathe per in. of tool travel on small work, and 3 revolutions per ditto for large work. The tool is held with the cutting edge aa close to the tool-post as can possibly be convenient, and the cutting speed is about 25 to 30 feet per minute on small work, and 18 feet on large work, the tool being hardened right out iu all cases.
FiNisHixo-TooL for WRoroHT-lRON, Cast-Iron, or Steel.— This is a finishing-tool for wrought-iron which will cut smoothly, clean, and true, beinir far preferable to the square-nosed tools sometimes used for the purpose of finishing iron, since such tools do not turn wrought-iron true, but follow the texture of the metal, cutting deepest in the softer parts, especially when their edges become in the least dull from use. This tool should be
10
MECHANICS.
held with the cutting edge as close in to the tool-post or clamp as it can conveniently be, with a quick speed and fine feed, soapy water being applied to the work. It may be also used for taking light roughing cuts on small work, and is, for such purposes, an excellent tool, especially upon work so slight as to be liable to spring, for which purpose the cutting point should not be much rounded. Ground very keen, it will answer admirably for copper work, the cutting speed being very great ; that is to" say, at least fourfold that given below, which is for finishing cuts on wrought or cast iron.
FINISHrNG-TOOL FOR WROUGHT-IRON, CAST-IRON, OR STEEL.
Size of work, inches diameter.
1 and less
1 to 3
2 " 5 5 " 12
12 " 30 20 and over
(-'lUtiiii; jiijood, feet per minute.
38 30 25 23 20 18
Peed.
30 25 20 20 16 14
This tool should always be hardi-ned right out ; and if used upon cast-iron, it should have less keenness upon tlie toj) face ; that is to say, the i)lane of the top face should be ground more nearly to the same plane as the top face of the body ()f the tool. For use upon steel, the top face must be ground more nearly horizontal — a rule which, we tiuiy hereoljservc, applies to all tools used upon wMuglit-iron. It sliould be placed in the lathe so tliat its cutting edge stands above the horizontal centre-line of the work.
FnoNT-Toor- kok Bhass-Wouk.— This is a complete master- tool, filling every necessary <|iialillcati<)ii for all plain outside l)rass work, ami dointr the duty on lliat metal wliicli the front tnol nrid right and left hand side-tools do on wrought iron. As shown in the engraving, it is ground to suit either roughing out
MECHANICS.
11
or finishing. For very sliglit work, wbicli is liable to spring, it may be ground a little more keen on the side faces, the top face not' requiring, under any possible circumstances or conditions, to be o-round keener than shown above. When held far out from the^'tool-post, the top face sliould be ground away, sloping down toward the cutting edge, wliich is done to prevent the tool from jarring or chattering. It should be hardened right out, and not
FRONT-TOOL FOR BRASS-WORK.
lowered or tempered at all, and used for roughing out at the following speed and feeds :
Size of work, in inclies.
1 and less
2 to 5 5 to 13
12 to 20
Revolutions of Lathe.
350 250 200 150
Peed. 25 25 35 30
For finishing-cuts, the cutting speed may be increased by about one fifth, which rule will also apply to its use upon yellow brass for roughing out as well as finishing purposes.
PARTING-TOOL.
Parting or Grooving Tool for Iron or Steel. — The part ing tool is applicable either to cutting grooves or for parting, or, in other words, cutting work aj)art. The cutting point, or end of the tool, is made thicker than the metal, both vertically and horizon- tally, behind it, so that the latter shall clear and not grind against the sides of the groove. This tool, especially if made thin to suit some especial purpose, is excessively liable to spring, in conse- quence of the pressure of the cut ; and if it commences to spring, it is apt to dig into the cut, and then break from the excessive
12
MECHANICS.
Strain. It is to prevent this digging in that the top face of the cutting part of the tool is placed so much below the top face of the body of the tool, which may, however, be dispensed with when the cutting edge is held close in to the tool-post, and the groov- ing is not required to be very deep. When, however, these re- quirements do exist, the form illustrated is absolutely indispen- sable to rapid and reliable duty, whether the tool be used in a lathe or a planiug-machine, the cutting edge of the tool being kept at about the horizontal centre of lathe-work, by packing- pieces placed beneath the body of the tool. If the width of the tool is not less than ,^^ inch, and does not require to cut a groove deeper than f inch, it should be hardened right out ; if, however, these conditions are reversed, it should be tempered to a dark straw, and for very weak tools even to a purple color, as lower- ing the temper increases the strength of all tools. If the groove to be cut is sufficiently broad to cause the tool to spring, it is best to use a narrower one and cut it out in two separate cuts, moving the tool.
PARTING-TOOL FOU BnA.*S.
Parting-Tool for Br.\ss. — The parting-tool for braes is gov- erned by the same principle as that for iron, save that its top face must be ground level, except in cases where the cutting edge stands far out from the tool-post, in which event the toj) face
KOl'OIIINO-TOOL FOH WUOIKillT-IUON.
must be ground away at an angle of which the cutting edge is flie lowest i)iirt. It is rarely, liowever, necessary for brass-work to grind tlie cutting edge imich below tin- level of tlie to]) face of the bo<ly of the tool, as is sliowti lor use on wroiight-iroii. 'Die
MECHANICS.
13
degree of hardness of the tool should be the same for brass as that given for wrought-iron.
ROUGHING-OUT Front Tool FOR Wrought-Iron.— Tlie en- graving represents the best possible form of tool for roughing out wrought-iron, or for removing a large mass of that metal in the lathe or planing-uiachine. When used on large work, it should be tempered to a light straw-color, which will leave it strong enough to stand without breaking the heavy strain due to the cut. It must be held very firmly, and with the cutting edge as close to the tool-post as it can well be.
The following are its rates of cutting speed and feed, the speed meaning the length of shaving it cuts off, and the feed implying the number of revolutions of the lathe necessary to feed the tool an inch along its cut :
Size of work. Cutting speed, Yeed
inches diameter. feet per minute.
1 and less 35 25 Ito 2 25 20
2 " 5 20 20 5 " 12 18 15
12 " 20 16 13
20 and over 15 12
For work of five inches diameter, and for all sizes below that, the tool should be hardened right out ; that is, made as hard as fire and water will make it, and not tempered at all. For work of a larger size, it should be tempered to a light straw-color. This tool, with the top face ground less keen, that is, more nearly horizontal, is an excellent one for steel, and the harder the metal to be cut, the more nearly horizontal the to]) face must be. It should be placed, for lathe- work, so that the cutting edge stands a little above the horizontal centre-line of the work.
SIDE-TOOL FOR BRASS.
Side-Tool for BRASS.^This tool fills the same place with re- ference to that metal that the side-tool and knife-tool do to iron- work ; and it has no superior for taking out corners, for cutting out holes or recesses which do not pass entirely through the metal. In conjunction with the front-tool for brass, already il- lustrated, it will perform almost any duty upon either inside or outside brass-work, except, of course, cutting out narrow grooves. Its cross-section is somewhat diamond-shaped, and it is made right and left by bending in opposite directions. It is a far better tool than those bent round at the end after the manner of a Ijor-
14
MECHANICS.
ing-tool ; and being more rigid, it is easier to forge and grind, and less liable to jar or chatter. It is equally applicable as aroughing- out or a finishing tool. It should be hardened right out, and used at the speeds and feeds given for the front-tool for brass.
PIDE-TOOI. KOK sglMllNL; ENDS OF ■\VKOCGHT-IR0N WORK.
Side- Tool for Squ.\uing Ends op Wrougiit-Iron Work. — The illustration represents a side-tool for wrought-iron, to be employed for squaring the ends of work held between the lathe centres, and in other cases wherein there is not sufficient room to admit a stouter tool. The cutting edge is shown at A, and .should be made more keen for wrought than for cast iron. In forging it, the hammering edgewise should be performed first, nor should any lianmiering be done to it edgewise after the steel lias lost its redness. It should, for light duty, and for all finishing pur- poses, be hardened right out, and, for heavy duty, be tempered to a straw-color. If, liowever, this tool is employed, as it some- times is, for very heavy duty on aslotting-machine, taking a cut, say, 2^ inches deep and \ inch thick, it must be lowered to a brownish purple and used at a cutting speed of about 10 feet per minute, and be ground so that the cutting edge first strikes the cut near the body of the tool, and not at the point end. For ordi- nary work, it is best used with a comparatively fine feed and quick speed, since it is not sufficiently strong, when made very hard, to stand heavy duty.
SIDE-TOOI, roil IKON.
SidkTooi, koh WRoufiHT Ikon, <'ast-Ii{()N, ok Stkrt.. — The engraving represents tlu; most superior side-tnoi for eitlier wrought or cast iron or steel, the only difTeniUce being that it requires to be less keen for tlie hitter than, as here hIkuvu, for tlie former. It la
MECHANICS.
15
employed to cut side-faces and to take out round or square cor- ners. For small work, it should be made so that it will cut at the point, and not on both edges at one time, when used in a square corner. For heavy work, it may be made more round-nosed, and allowed to cut all round the curve ; and it will, in either shape, work equally well as a roughing-out or as a finishing tool, only requiring to be ground more keen to fit it for finishing pur- poses (which should be, on wrought-iron, performed with soapy water applied to the work), and at a faster speed and finer feed. For taking out a round corner or fillet in slight work, which is liable to spring from the pressure due to the cut, the point must be rounded very little, the curve being made by operating both the straight and cross feeds of the lathe. This tool is made right or left handed by simply bending it in the required direction, that illustrated being a left-hand tool. It should be made as hard as fire and water will make it, and used at the following speeds and feeds :
|
iameter of woi |
■k, |
Speed, in |
"P'pPfl |
|
in inches. |
feet, per mtnute. |
J: ecu. |
|
|
1 and less |
30 |
30 |
|
|
1 to 2 |
25 |
25 |
|
|
2 " 5 |
22 |
20 |
|
|
5 " 12 |
20 |
20 |
When, however, it is employed for roughing-out purposes, these speeds may be, with advantage, slightly diminished and the feeds increased.
SPRING-TOOL.
Spring-Tool for Use on Wrought-Iron, Cast-Iron, Steel, OR Br.\ss. — The spring-tool is especially adapted to finishing sweeps, curves, or round or otlier corners, and will answer for any metal whatever. As illustrated, the fiice is given an up ward incline to make it sufficiently keen for wrought-iron or steel. For brass-work, this face should be made horizontally level, or, if the cutting stands with its cutting edge far out from the tool-])ost, it may be inclined downward to make it cut smoothly. The piece of wood shown driven in the bend is to correct any tendency of the tool to s]iring away from the hard
16
MECHANICS.
parts of the metal, as it is apt to do. The spring-tool does not turn so true as is desirable, still the smoothness of its finish makes it the most desirable tool for tlie purposes mentioned. It should have its face filed up very smoothly before bein<j hardened, and should not be ground on that face. The applica- tion of the oilstone greatly improves its value for finishinfr. It should, for all purpose, be tempered to a brown color on the face, and left soft around the bend.
TOOLS.
Borino-Bar for Lathe- Work. — In boring work chucked and revolved in the lathe, such, for instance, as axle-boxes for lo- comotives, the boring-bar here shown is an excellent tool. A represents a cutter-head, which slides along, at a close working fit, upon the bar, D D, and is provided with the cutters, B B B,
BORINH-BAR.
whicli are fastened into slots jjrovidcd in the head, A, by the keys shown. The bar, \) D, has a thread cut ui)on part of its length, ilie remainder being plain, to fit the sliding head. One end is squared to receive a wrench, which, resting against the bod of the lathe, jiri'VentB the barfroni revolving upon the lathe centre, F F, by wliich the bur is held in the lathe. (J (i (» are plain washers, jtrovided to make iij) tht; distance between th(^ thread and ])lain part of th<^ bar, in cases wIkmo the sliding liead, A, requires con- siderable lateral movement, there being more or fewer washers employed accorcliiig to the distance along whicli the sliding head is re<|uired to move. The edtres of these washers an; chamfered off to ])reveiit them from burring easily. To fe(>d the cutters, the iMit, II, is sirewed up with a wren<h.
'{'he cutter head, A, is provided in its bore with two feathers, wliicli slide in grooves i)rovided in tlm bar, D 1), thus prevent- ing the hea<l from revolving upon the bar. It is obvious that
MECHANICS.
17
tliis bar will, in consequence of its rigidity, take out a mucli heavier cut than would be possible with any boring-tool, and furthermore that, there being four cutters, they can be fed up four times as fast as would be possible with a single tool or cut- ler.
Boring-Tools, Shapes of.— The pressure on the cutting edge of a tool acts in two directions, the one vertical, the other lateral. The downward pressure remains at all times the same ; the lateral pressure varies according to the direction of the plane of the cutting edge of the tool to the line or direction in which the tool travels : the general direction of the pressure bein^ at a right angle to the general direction of the plane of the cutting edge. For example, the lateral pressure, and hence the spring of the various tools, shown in the cut, will be in each case in the direction denoted by the dotted lines. D is a section of a piece of metal requiring the three inside collars to be cut out ;
LATEBAL PRESSURE OP TOOLS.
A, B, and C are variously shaped boring-tools, from which it will be seen that A would leave the cut in proportion as it suffered from spring, which would increase as the tool edge became dull, and that the cut forms a wedge, tending to force the tool toward the centre of the work. B would neither spring into nor away from the cut, but would simply require more power to feed it as the edge became dulled ; while C would have a tendency to run into the cut in proportion as it springs ; and as the tool edge be- came dull, it would force the tool-point deeper and deeper into the cut until something gave way. Now, in addition to this con- sideration of spring, we have the relative keenness of the tools, it being obvious at a glance that (independent of any top rake or lip) C is the keenest and A the least keen tool ; and since wrought-iron requires the keenest, cast-iron a medium, and brass the least keen tool, it follows that we may accept, as a rule, C for wrought iron. B for cast-iron, and A for brass-work. In Fig. 2, B represents a section of the work, No. 1 represents a boring-tool with top-rake, for wrought-iron, and No. 2 a tool without top- rake, for brass-work, which niny be also used for cast-iron when the tool stands a long way out from the tool i)Ost or clamp, under which circumstances it is liable to jar or chatter. A tool for use
18
MECHANICS.
on wrouglit-iron should have the same amount of top-rake, no matter how far it stands out from the tool-post ; whereas one for use on cast-iron or brass requires to be the less keen the further it stands out from the tool-post. To take a very smooth cut on brass-work, the top face of the tool, shown at 3 in Fig. 3, must be ground off, as denoted by the dotted line.
We have now to consider the most desirable shape for the corner of the cutting edge. A positively sharp corner, unless for
Kiii. i.
a Bperial j)urposo, is very und<'siral)I<', Ijccausc the (extreme point soon wears iiway, leaving the ctitting (jiiaiilication (rf the tool almost di'Hlroyt'd, and l)ccaii.st! it Icuvch the work rough, and can only i)e employed with a very fine feed. It may l)e aciej)ted as a general ruh^ tluit, for roughing cuts, till- ciiini-r should be suili- ci.Mitly rounded to give strength to thf lool-jKjint ; while, in fini.-hiMir <iitH, the point may be nnidr as round us jtossibh! with- out ciinsin^Mhr tool to jar or chati.T. Now, sinn- the tendency
MECHANICS.
19
of the tool to jar or chatter depends upon four points, namely, the distance it stands out from the tool-post, the amount of top- rake, the acuteness or keenness of the general outline of the tool, and the shape of the cutting corner, it will he readily seen tliat
FIG. 3. — VARIOUS FORMS OF BORING-TOOLS.
judgment is required to determine the most desirable form for any particular conditions, and that it is only by understanding the principles governing the conditions that a tool to suit them may be at once formed. In Fig. 3 will be fouud the various forms of boring-tools for ordinary use. No. 1 is for use when the condi- tions admit of a heavy cut on wrouglit-iron. No. 2 is for use on wrought-iron when the tool stands so far from the tool-post as to be necessarily subject to spring. No. 3 is to cut out a square corner at the bottom of a hole in wrought-iron. No. 4 is for taking out a heavy cut in cast-iron. No. 5 is for taking out a finishing cut in cast-iron when the tool is proportionally stout, and hence not liable to spring or chatter ; the point being flat, the cutting being performed by the front corner, and the back part being adjusted to merely scrape. No. 6 is for use on cast- iron under conditions in which the tool is liable to jar or spring.
Chilled Cast-Iron Tools, To cast, for cutting chilled iron. — Make a tool of the required shape out of wrought iron, then case the chilled part, using charcoal-iron No. 5.
Chipping.— The chisel requires special notice since it is fre- quently made of the most ill-advised shape (for either cutting smoothly or standing the effects of the blow), that is, hollow, as in Fig. 1, in which case there are two sections f)f metal, repre- sented by the dotted lines, a a. which are very liable to break, from their weakness and from the strain outward placed upon them by the cut, which, acting as a wedge, endeavors at each blow to drive thcni outward instead of inward, as would be
20
MECHAJaCS.
the case in a properly shaped chisel, as shown iu Fig. 3, a being the cutting edge.
When using, hold it firmlv against the cut, and it will do its work smoother and quicker.
The cape, or, as it is sometimes called, cross-cut chisel, is em- ploN-ed to cut furrows across the work to be chipped, which fur- rows, being cut at a distance from each other less in width than the breadth of the flat chisel, relieve the flat chisel and prevent its corners from " digging in" and breaking. If a large body of metal requires to be chipped ofE cast-iron or brass, the use of the
•a.
a
riti. 1.
FIG. 2.
COLD CHISELS.
cape-chisel becomes especially advantageous, for the metal, being weakened by the furrows, will break away in pieces from the force of the blow, without requiring to be positively cut by the chisel ; but care must be tukeu to leave sufficient metal to take a clean finishing cut ; for when the metal is broken away, by the force of the blow, it is ai)t to break out below the level of the cut. It is also necessary to nick deeply with a chisel the outside edges of the work at the line representing the depth of the metal to be chipped off, so that the metal shall not break away at the edges deeper than the cut is intended to be.
Chisels, Cold, To grind. — Grind a cold-chisel so that its cut- ting edge is rounding and not hollow, as it is often made. A rounded chisel is stronger and cuts smoother. A hollow chisel has no useful place as a chipping-tool.
Chisels, Cot.d, To harden. — Heat the chisel to a distance about equal to its width, immerse it about half that distance in the wa- ter, hold it still about four seconds, suddenly dip it a little deeper, and then withdraw. Urightt n one flat surface with a I)iece of grindstone or an cniery-block ; then l)rnsh the hand or a piece of waste over the brightened surface to remove Ww false color, and finally cool out in the water, when the clear blue color api)ears.
CiilsPM.H, C<ti,i), To hold. — IIolil u cold-chisel firmly to its cut, without removing it at every blow. This will incr<-iise its effec- tiveness, and decrease its liability to break from a foul blow.
CliisKi.H, Cold, To remove burrs from the heads of. — When tlie head of a cold-cliisrl is burn d over from use, rest the head ujnm a l>lock of iron, and strike tin- burrs from the under side, and tiny will l)r<'!ik n-adily and easily olT.
MECHA^^cs.
21
Chisels, Cold, Use of. — These sliould be kept thin at the cut- ting end, which saves time and entails less labor in using.
Cone-Plate for boring in the lathe. — For chucking shafts and other similar work in tbe lathe (to bore holes in the ends of the shafts, etc.), the cone-plate shown in the engraving is the best appliance known to machinists. A is a standard, fitting in the shears of the lathe, at E, and holding the circular plate, C, by means of the bolt, B, which should be made to just clamp the plate, C, tightly when the nut is screwed tight. The plate con- tains a series of conical holes, 1, 2, 3, etc. (shown in section at D). The object of coning the pin, B, where it carries the plate, C, is that the latter shall be made to a good working fit and have no play. The operation is to place the shaft in the lathe, one end being provided with a driver, dog, or carrier, and placed on the running or line centre of the lathe ; and the other end, to be
CONE-PLATE FOR BORING Df THE LATHE.
operated upon, being placed in such one of the conical holes of the plate, C, as is of suitable size, the distance of the standard, A, from the lathe-centre is to be adjusted so that the work will revolve in the coned hole with about as much friction as it would have were it placed between both the lathe-centres. Thus the conical hole will take the place of the dead-centre of the lathe, leaving the end of the shaft free to be operated on. F F are holes to bolt the standard, A, to the lathe shears or bed ; and G G, etc., are taper-holes to receive the pin, G, shown in the sec- tional view. The object of these holes and pin is to adjust the conical holes so that they will stand dead true with the lathe- centres ; for if they stood otherwise, the holes would not be bored straight in the work. In the engraving, hole No. 7 is shown in position to operate, the pin, G, locking the plate, C, in that position. In setting the work, the nut on the pin, B, should be eased back just sufficiently to allow the plate. C, to revolve by hand ; the work should then be put into position, and the pin, G, put into place ; the standard. A, should then be adjusted to
Q2
MECHANICS.
its distaiKM' from till- live liillif-centre, and bolted to tlie lathe- bed ; and linally, the nut on the pin, B, should be screwed up tight, when the work will l)e held true, and tlie cone-plate pre- vented from f^pringing. Care must be taken to t^upply the coni- cal holes, in which the work revolves, with a liberal quantity of oil, otherwise they will be apt to abrade.
Cutters and Reamers, To prevent, cracking when being hardened. — Drill a small hole from tlie side to meet the large one at its enclosed termination.
Cutters for Boiler-Platr and similar Work.— Cutters are steel bits, usually held in either a stock or bar, being fitted and keyed to the same ; by this means, cutters of various shapes and sizes may be made to fit one stock or bar, thus obviating the ne- cessity of having a multiplicity of these tools. Of cutter-stocks, whicli are usually employed to cut out holes of comparatively large diameter, as in the case of tube-plates for boilers, there are two kinds, the simplest and easiest to lie made being tliat shown below.
Cl'TTBRt:.
A is the stock, through wiiich runs a slot or keyway into which th(! cutter, ii, fits, being locked by tlie key, (". D is a pin to steady tlu; tool while it is in operation. Holes of the size of the pin, f), are first drilled in the work, into which the ])in fits. To obviate the nectissity of drilling these holes, somc^ modern drill- stocks Imve, in place of the pin, D, a conical-ended pin which acts as a centre, and which fits into a centre punch mark made in the eenfre of the hole to be cut in the woi'k Most of these devices are patenteil, and the in'mciple u|)oii which they act will be un- derstoo'i from the second enf-raving, A being the stock to whicli
MECHANICS.
23
the cutters, B B, are bolted with one or more screws. (' is a spiral spring working in a hole in the stock to receive it. Into the out- er end of this hole fits, at a working fit, the centre, D, wliich prevented from being forced out (from the pressure of the spring
IS
CUTTERS.
C) by the pin working in the recess, as shown. E is the plate to be cut out, from which it will be observed that the centre, D, is forced into the centre-punch mark in the plate by the spring, C, and thus serves as a guide to steady the cutters and cause them to revolve in a true circle, so that the necessity of first drilling a hole, as required in the employment of the form of stock shown in the first figure, is obviated.
Cutting Square Threads, Tools for.— For cutting square threads, the tool here represented is used. The point at C is
JicrJ4>.
'T
TOOL Foil CUTTING SQUARE THREADS.
made thicker than the width at D, so as to give the sides clear- ance from the sides of the thread. At B it is made thinner, to give the tool clearance, and deeper to compensate in some mea- sure for the lack of substance in the thickness. The top face
24
MECHANICS.
may, for wrought-iron or steel, be ground hollow, C being the liifihest point, to make it cut cleaner ; while, when held far out from the tool-post for use on brass-work, the face, C D, may be ground at an incline, of which C is the lowest point, which will prevent the tool from springing into the work.
If the pitch of the screw to be cut is very coarse, a tool nearly one half of the width of the space between one thread and the next should be employed, so as to avoid the spring which a tool of the full width would undergo. After taking several cuts, the tool must be moved laterally to the amount of its width, and cuts taken ofE as before until the tool has cut somewhat deeper than it did before being moved, when it must be placed back again into its first position, and the process repeated until the re- quired depth of thread is attained.
Sr-KEW ni'RINr. ctjttino
The abov(> figure represents a thread or screw during the above- described ))n)cess of cutting, a a a\s the groove or space taken out by tilt! cuts liefore the tool was moved ; B B represents tlie first cut taken after it was moved ; c is the point to which the cut, B, is supposed (for the purpose of this illustration) to have traveled.
The tool used liaviiig been a little less than one half the proper width of th(! space <>f the tliread, it becomes evident that the thread will be l(!ft with ratluT more than its jiroprr thickne.s.x, wliicli is done to allow finishing-cuts to be taken uj)on its sidi'S. for which purpose the knife-tool already described is brought into requisi- tion, care being taken that it is placed true, so as to cut i)()th sides f)f the tliread of an cfiual angle to the centre-line ot the Kcr(!w.
AfljuKtdhle dies, tliat is, those which take nion^ than one cut to make a full tliread, should never be used in cases where a solid die will answer the jturpose, because adjustable dies take every cut at a (lifTerent angle to the ceiitre-liiie of the bolt, as ex]ilaiiied by the following engravings.
Tlie first re]>resents an ordinary screw. It is vvident that the ))itcli from (I to B is the same as from (' to D, tlu; one being the to]), the otlier the liottom, of the thread. It is also evident that a piece of cord wound once around tlie top of the thread will be longer than one wound once around tlie bottom of the thread,
MECHANICS.
25
and yet, in passing once around tlie thread, the latter advanced as much forward as the former, that is, to the amount of the pitch of the thread. To illustrate this fact, let a b, in the follow- ing diagram, represent the centre-line of the bolt lengthwise, and
B a
ORDINARY SCREW.
c d a, line at right angles to it ; then let from the point e to the point /represent the circumference of the top of the thread, and from e to g the circumference of the bottom of the thread, the lines 7i 7i representing their respective pitches ; and we have the line k as representing the angle of the top of the thread to the centre-line, a b, of the bolt, and the line I as representing the angle of the bottom of the thread to the centre-line, a b, of the bolt, from which it becomes apparent that the top and the bot- tom of the thread are at different angles to the centre-line of the bolt. The tops of the teeth of adjustable dies are themselves at the greatest angle, while they commence to cut the thread on the bolt at its largest diameter, where it possesses the least angle, so
Ch
that the dies cut a wrong angle at first, and gradually approach the correct angle as they cut the depth of the thread. From what has been already said, it will be perceived that the angle of thread cut by the first cuts taken by adjustable dies, is neither that of the teeth of the dies nor that required by the bolt, so that the dies can not cut clean because the teeth do not fit the grooves they cut, and drag in consequence.
26 MECHANICS.
Dies for use in hand-stocks are cut from hubs of a larger dia- meter than the size of bolt the dies are intended to cut : this being done to cause the dies to cut at the cutting edges of the teeth which are at or near the centre of each die, so that the threads on each side of each die act as guides to steady the dies and pre- vent them from wabbling, as they otherwise would do ; the result of this is that the angle of the thread in the dies is not the cor- rect angle for the thread of the bolt, even when the dies are the closest together, and hence taking the finishing-cuts on the thread, although the dies are nearer the correct angle when in that posi- tion than in any other. A very little practice at cutting threads with stocks and dies will demonstrate that the tops of the threads on a bolt cut by them are larger than was the diameter of the bolt before the thread was commenced to be cut, which arises from the pressure placed on the sides of the thread of the bolt by the sides of tlie thread on the dies, in consequence of the difference in their angles ; which pressure compresses the sides of the bolt-thread (the metal being softer than that of the dies), and causes a corresponding increase in its diameter. It is in con- sequence of the variation of angle in adjustable dies that a square thread can not be cut by them, and that they do not cut a good V-thread.
In the case of a solid die, the teeth or threads are cut by a hub the correct size, and they therefore stand at the proper angle ; furthermore, each diameter in the depth of the teeth of the die cuts the corresponding diameter on the bolt, so that there is no strain upon the sides of the thread save that due to the force ne- cessary to cut the metal of the bolt-thread.
Cutting versus Sckaping Tools. — A tool will either cut or scrape, according to the position in whidi it is held, as. for in- stance, below the line A in the illustration. Line A is in each
CUTTING AND SCRAPINO.
casi! onf drawn from tlie centre of tlu! work to th(! jjoint of con- tact betwe(!ii tin; tool edge and tlie work, (' being tlie work, and
MECHANICS.
27
B the tool. It will be observed that the angle of the top face of the tool varies in each case with the line A. In position 1, the tool is a cutting one ; in 2, it is a scraper ; in 3, it is a tool which is a cutter and scraper combined, since it will actually perform both functions at one and the same time ; and in 4, It is a good cutting tool, the shapes and angles of the tools being the same in each case.
Dies, Fitting, to quadrants when either the dies or quadrants, or both, are to be hardened. — -Make them a shade too small, to al- low for their swelling during the process of hardening.
Dies, To ease hardened, that fit too tightly. — Supply them with very fine emery and oil, and work them backward and for- ward in their place along the travel.
Dies, To renew worn-out. — Slightly close the holes by swaging, fill the clearance-holes with Babbitt-metal, and recut them with the hub.
COUNTERSINK-PnSf DRILLS.
Drills, Countersink-Pin. — Of these tools there are various forms. The following figure represents a taper countersink such as is employed for holes to receive flush rivets or countersunk head-bolts, this form of tool being mainly employed for holes above 1^ of an inch in diameter. It should be made, tempered, and used as directed for pin-drills. In tempering these tools, or any others having a pin or projection to serve as a guide in a hole, the tool should be hardened right out from the end of the pin to about f of an inch above the cutting edges. Then lower the temper of the metal (most at and near the cutting-edges), leaving the pin of a light straw-color, which may be accomplished by pouring a little
28
MECHANICS.
oil upou it during the lowering or tempering process. The object of this is to preserve it as much as possible from the wear due to its friction against tlie sides of the hole. For use on wrought-irou and steel, this countersink (as also the piu-drill) may have the front face hollowed out, after the fashion of the lip-drill, and as shown by the dotted line.
Drills, Slot, for key ways. — For drilling out oblong holes, such as key ways, or for cutting out recesses such as are required to re- ceive short feathers in shafts, the drill known as a slotting-drill, here shown, is brought into requisiiion. No. 1 is the form in
EDGE VIEW
tND VIEW
^J\/Pl. £
END VIEW
A A
EDGE VIEW SIDE VIEW
rifl. 1.— HI.0T-DRI1.L8.
which this tool was employed in tlie early days of its introduc- tion ; it is thtr Htrongi^r form of the two, and will tak(^ the heaviest cut. 'J'iie ol)j('ctioti to it, liowevor, is that, in cutting out deep slots, it is !ipt to drill (lut of true, the hoh' gradually running to one side. Tlur iiictlioil (»f u.sing tlicse drills is to move tlu^ work Inick and forth, in a chuck i)rovided for the ])urpose, the drill re- maining .stationary. If these tools were used as common drills, they would cut lioles of the form shown in Fig. 2.
FiLKs, TIk? use of. — In draw-liliug, take short, quick strokes, which will prevent the file from iiinning and scratching. Long
MECHANICS.
29
strokes, no matter how long the work may be, are useless save to make scratches. Remember that it is less tlie number of strokes you give the tile than the weight you place upon it that is effec- tive ; tlierefore, when using a rough tile, stand suflaciently away from the vise to bring the weight of the body upon the forward stroke. New files should be used at first upon broad surfaces, since narrow edges are apt to break the teeth if they have the fibrous edges unw'orn. For brass- work, use the file on a broad surface
FIG. 2.— SLOT-DRILLS.
until ts teeth are dulled, then make two or three strokes of the file under a heavy pressure upon the edge of a piece of sheet-iron, which will break off the dulled edges of the teeth, and leave a new fibrous edge for the brass-work. Use bastard-cut files to take off a quantity of metal of ordinary hardness ; second-cut, in fitting, and also to file unusually hard metal ; smoothing, to fin- ish in final adjustment or preparatory to applying emery-cloth ; dead smooth, to finish very fine work ; float-file on lathe-work.
FiliES, To prevent scratching by. — To prevent files from pin- ning, and hence from scratching, properly clean them, and then chalk them well.
Files, To resharpen. — (1) Carefully clean them with hot water and soda, then place them in connection with the positive pole of a battery in a bath composed of 4 parts of sulphuric acid and 100 parts water. The negative pole is to be formed of a copper spi- ral, surrounding the files but not touching them ; the coil termi- nates in a wire reaching above the surface. Leave the files in the bath ten minutes, then carefully wash them off, dry, and oil. (2) Carefully clean the files in hot water and soda, and dip for 40 minutes in nitric acid of 41^ B.
Files, To select. — To choose a flat file, turn it edge upward, and look along it, selecting those that have an even sweep from end to end, and having no flat places or hollows. To choose a half-round file, turn the edge upward, look along it, and select that which has an even sweep, and no flat or hollow places on the half-round side, even though it be hollow in the length of the flat side.
Gravers, Grinding. — Gravers should be ground on the end only, and not on the sides of the square, except when applied to brass-work.
Half-Round Bits. — For drilling or boring liolesvery true and parallel in the lathe, the half-round bit shown in the engraving
30
MECHANICS.
is unsurpassed. The cutting edge. A, is made by backing off the end, as denoted by the space between the lower end of the tool and the dotted line, B, and performing its duty along the radius, as denoted by the dotted line in the end and top views. It is only necessary to start the half-round bit true, to insure its boring a hole of any depth true, })arallel, and very smooth. To start it, the face of the work should, if circumstances permit, be made true ; this is not, however, positively necessary. A recess, true and of the same diameter as the bit, should be turned in the work, the bit then being placed in position, and the dead-centre employed to feed it to its duty, which (if the end of the bit is square, if a flat place be filed upon it, or any other method of holding it sufficiently tight be employed) may be made as heavy as the belt will drive. So simple, positive, and effective is the operation of this bit that (beyond starting it true and using it at a moderate cutting speed, with oil for wrought-iron and steel) no further instructions need be given for its use.
KKi. 1.— IIALF-ROUNI) BITS.
In Fig. 2 is shown .\, a Imriiig I)ar ; 1? M is the sliding lii-ad ; (.' C is tlie bore of the cylinder, and 1, 2, and ',i are tools in the j)ositionH pliown. D I) 1) are projections in the bore of the cylin- der, causing an exce.saive amount of duty to be ])laced ujion the cutters, as soIM(•tiInc^s occurs wlien a cut of medium depili lias been h-tiirti'd. Siidi a cut incniases on <mt'. side of the l)ore of tlie work until, liecoming excessive, it causes the bar to tremhlt; and
MECHANICS.
31
the cutters to chatter. In sucli a case, tool and position No. 1 would not be relieved of any duty, though it spring to a consider- able degree ; because the bar would spring in the direction de- noted by the dotted line and arrow E, while the spring of the tool itself would be in the direction of the arrow, F. The ten- dency of the spring of the bar is to force the tool deeper into the cut instead of relieving it ; while the tendency of the spring of the tool will scarcely afEect the depth of the cut. Tool and position No. 3 would cause the bar to spring in the direction of the dotted line and arrow G, and the tool itself to spring in the direction of H, the spring of the bar being in a direction to in- crease, and that of the tool to diminish, the cut. Tool and posi- tion No. 3 would, however, place the spring of the bar in a direc-
FIG. 2— SPRING OF BORING TOOLS.
tion which would scarcely affect the depth of the cut, while the spring of the tool itself would be in a direction to give decided relief by springing away from its excessive duty. It must be borne in mind that even a stout bar of medium length will spring considerably from an ordinary roughing-out cut, though the lat- ter be of an equal depth all round the bore, and from end to end of the work. Position No. 3, in Fig. 2, then, is decidedly prefer- able for the roughing-out cuts. In the finishing cuts, which should be very light ones, neither the bar nor the tool is so much affected by springing ; but even here position No. 3 main- tains its superiority, because, the tool being pulled, it operates somewhat as a scraper (though it may be as keen in shape as the other tools), and hence it cuts more smoothly. It possesses, it is true, the defect that the distance from the cutting point stands further out from the holding-clamp, and the tool is hence more apt to sprinof ; and in cases where the diameter of the sliding head is muchless than that of the hole to be bored, this defect may possess importance, and then position No. 2 may be prefer-
32 MECHANICS.
able ; but it is an error to employ a bar of small diameter com- pared to that of the work.
To obtain the very best and most rapid result, there should be but little space between tiie sliding head and tbe bore of the work ; the bar itself should be as stout as is practicable, leaving the sliding head of sufficient strength ; and if the bar revolves in journals, these should be of large diameter and with ample facili- ties for taking up both the diametrical and end play of the boxes, since the one steadies the bar while it is performing boring duty, and the other while it is facing off end faces, as for cylinder-cover joints.
Hammers, Chipping. — These should weigh about If lbs., and have handles 15 inches long.
Metal having a very hard Skin, Tools used for. — When the skin of the metal to be cut is unusually hard, as frequently oc- curs in cast-iron, the shape of the cutting part of the boring-tool must be such that its point will enter the cut first, so that it cuts the inside and softer metal. The hard outside metal will then break off with the shaving without requiring to be cut by the tool edge, while the angle of tlie cut will keep the tool point into its cut from the pressure required to break the shaving. A tool of
FIO. 1.— TOOL FOK HARD METAL.
this description is represented in the engraving, Fig. 1. a is the point of the tool, and from a to B is the cutting edge ; the dotted lines, c and D, represent the depth of the cut, c being the inside skin of the metal, sup])osed to be hard. The angle at which the cutting edge stands to the cut causes the pressure, due to tlie bending and fracturing of the shaving, to be in the direction of e, which keeps the tool jjoint into its cut ; while the resistance of the tool point to this force, reacting upon the cut, from a to B, causes the hard skin to break away. For use on wrought-iron, however, th(! tool presented below will work to bett<!r advantage, it being a side-tool. In the event of a side face Ix'ing very hard, it possesses the advantage that the ])ointof the tool nuiy be made to enter the cut first, and, cutting beneath the hard skin, fracture it off without cutting it, the ])rcssur(' of the shaving on tlie tool kecj)iiig th(! bittiTto its cut, as shown in Fig. 2.
/t is the ciittiii<r part f)f the tool ; B is a shaft with a collar on it ; c is the side rut being taken off the collar, and D is the face, supposed to be hard. The cut is luire sliown as being commenc- ed from the largest diameter of thi' collar, and being fed inward so that the point of the tool may cut well beneath tlie liard face, ]), and HO that the pressure of the cut on tlie tool may keep it to
MECHANICS.
33
its cut, as already explained ; but tlie tool will cut equally as ad- vantageously if the cut is commenced at the smallest diameter of the collar and fed outward, if the skin, D, is not unusually hard.
rop VIEW
FIG. 2. — TOOl, FOR HARD METAL.
Plane-Irons, Carpenters', To grind.— The
angle
of a plane- iron should be about 25°
Plane Irons, Angle of, to face of planes.— For soft wood, 50° ; for mahogany, 50° ; for soft wood for mouldings, 55° ; for hard
DEVICE FOR GRINDING PLANE-IRONS.
wood for mouldings, G0\ With this device, one man can both turn the stone and grind the tool much more accurately than by holding it in his hand.
34 MECHANICS.
A is a piece of spring-steel, 8 inches long, bent at eacli end, with thumbscrew. You grasp the holder with the left hand at B, sticking the point, C, into a board or the wall, at sucli a dis- tance from the stone as to bring the iron, D, in the right position on the stone. By raising or lowering C, the bevel is regulated.
Raws .\nd Springs, Hardening. — The usual way of proceed- ing is to heat the saws in long furnaces, and then to immerse them horizontally and edgewise in a long trough containing the composition ; two troughs are commonly used alternately. Part of the composition is wiped off with a piece of leather, when the articles are removed from the trough ; they are then heated one by one over a clear coke fire until the grease inflames ; this is called " blazing ofE." A greatly recommended composition consists of 2 lbs. of suet and J lb. of beeswax to every gallon of whale oil ; these are boiled together, and will serve for thin articles and most kinds of steel. The addi- tion of black resin, to the extent of about 1 lb. to the gallon, makes it serve for thicker pieces, and for those it ref usetl to harden before ; but the resin should be added with judgment, or the articles will become too liard and brittle. The composition is useless when it has been constantly employed for about a month ; the period depends, however, on the extent to which it is used, and the trough should be thoroughly cleaned out before the new mixture is placed in it. The following recipe is commended : 20 galls, spermaceti-oil, 20 lbs. melted and strained beef suet, 1 gall, neats'-foot oil, 1 lb. pitch, 8 lbs. black resin. These last two articles must be previously melted together, and then added to the other in- gredients ; the whole must then be heated in a proper iron vessel, with a close cover fitted to it, until the moisture is entirely evaporated, and the composition will take fire on a flam- ing body being ])resented to its surface ; the flame must be in- stantly extinguished again by putting on the cover of the vessel. When the saws are wanted to be rather hard, but little of the grease is burned off ; when milder, a largi; portion ; and for a spring temper, the whole is allowed to burn away. When the work is thick, or irregularb' thick and thin, as in some springs, a second and third dose is burned oil', to insure equality of temper at all points alike. Gun-lock springs are sometimes lite- rally fried in oil for a considerable time over a fire in an iron tray. The thick parts are then sure to be sufficiently reduced, and tin; thin parts do not become the more softened from the continuance of the, blazing heat. Si)rings and saws ap])ear to lose their elasticity after hardening and tempering, from tlie re<luction ami friction they undergo in grinding and ])()lishing. Toward the conclusion of the manufacture, the elasticity of tln^ saw is re- Ktor»!d princii)ally by hammering, and partly by lu-ating over a clear coke fire, to a straw-color ; the tint is removed by very diluted muriatic aciid ; after wliicli the saws aro well washed in plain wat(,r and liried.
Saws, Band, To solder. — Scarf tlio end of the saw to a taper for a distance of two liiu! or on<! coarse tooth, fitting thi; edgtis of tlio scurf very true and level. Clean the joint with acid, and clamp the
MECHANICS. 35
saw ends together with a suitable frame or clamp. Heat the joint with a pair of red-hot tongs, and place a small strip of jeweler's silver solder upon the joint ; press it upon the same with the red-hot tongs. As soon as the solder has properly run or flowed, remove the tongs and cool the joint with water, to re- store as far as possible the temper of the saw. Then hie the joint to an even thickness and level with the rest of the saw, using a wire gauge as a template. Saws, Circular, Speeds for :
|
Diameter of |
|||
|
saw, |
Revolutions per minute for |
Eevolutions per minute for |
|
|
inches. |
English or thin |
saws. |
American or thick saws. |
|
36 |
1000 |
1500 |
|
|
30 |
1200 |
1800 |
|
|
25 |
1400 |
2100 |
|
|
20 |
1500 |
2400 |
|
|
15 |
1800 |
2700 |
|
|
10 |
2900 |
3000 |
Circular saws of over 40 or 50 inches in diameter are, or should be, hammered to run at a certain speed. This is more important when the speed is as high as from 700 or 900 revolutions per minute. If a saw is so hammered as to do good work at 300 or 400 revolutions per minute, it will not do as good work at 900, for the reason that the high speed expands the outside or rim, causing it to dish, or " flop around," as sawyers sometimes express it. In such cases, and when it is inconvenient to reduce the speed, it will be necessary to guide the saw out of the log so as to cause the central part to rub against the log enough to heat it slightly, thus expanding the portion that needs hammering. An expert sawyer can in this way manage indifferently well, though at an expense of considerably more power. A large saw, to run well at high speed, should be hammered in the centre part until it is slightly dishing, or, as it is variously expressed, "loose at the eye," or " rim-bound." It may be loose at the eye when it is the reverse of rim-bound, namely, too open at the rim, which is the most frequent trouble with such saws. They all become so eventually from use, and should then be rehammered.
Saws, Hints concerning. — A saw just large enough to cut through a board will require less power than a saw larger, the number of teeth, speed, and thickness being equal in each. The more teeth, the more power, provided the thickness, speed, and feed are equal. There is, however, a limit, or a point where a few teeth will not answer the place of a larger number. The thinner the saw, the more teeth will be required to carry an equal amount of feed to each revolution of the saw, but always at the expense of power. When bench-saws are used, and the sawing is done by a gauge, the lumber is often inclined to clatter and to raise up the back of the saw, when pushed hard. The reason is that the back half of the saw, having an upward motion, has a tendency to lift and raise the piece being sawn, especially when it springs and pinches on the saw, or crowds between the saw and the gauge ; while the cut at the front of the saw has the opposite tendency of holding that part of the piece down. The hook or
36
MECHANICS.
pitch of a saw-tooth should be on a line from J to ^ the diame- ter of the saw : a } pitch is mostly used for hard, and a ,^- for softer timber. For very fine-toothed saws designed for heavy work, such as sawing shingles, etc., even from suit wood, ^ pitch is best.
SAW-TEETH.
Saw-Teetr, Shapes of. — No. 1 is a good-shaped tooth for very soft wood, the wide bevel being the front of the tooth. The point would be liable to break or bend in very hard wood or in knots. No. 2 will stand to saw the hardest timber or knots, but will not cut as easily as No. 1. No. 3 is a form of point general- ly used for promiscuous sawing of both liard and soft wood. The set must be wide enough to clear the plate. After filing your saw, place it on a level board and pass a whetstone over tlie side of the teeth until all the wire-edge is off them. This will make the saw cut true and smooth, and it will remain sliarj) longer. The saw must be set true with a saw-set.
Scrapers, To make. — Old files which have never been recut make excellent scrapers.
Scrapers, Use of. — All work should be fitted as nearly true as possible before being scrajied with the fiat scraper, which is in- tended for fl;it surfaces only. For hollow work, curves, etc., the half-round scraper is the best, the three-cornered being the least efficient of all scrapers.
Taps and Reamers, Finishing. — The forgings are got out in the usual way, left to anneal, centred, and turned just sufficient to remove the scale. Then anneal again, and tuiii dt)wn to within ^V iiK'h, or less, of finisliing size. Anni-al once more, and finish in the lathe. If not sprung in turning, the taj) or reamer will come out all riglit when hardened. This hiis been tested euccess- f'uliy with taps from i inch in diameter and IJ iuclies long up to those of 1 inch in diameter and 2 feet long.
Taps, Temixsring and hardening. — 'i'o harden a tap, heat to a cherry-red, in a clear and not a blazing lire, or, what is better, heat in cliarcoal, liolding tlie tap by the square end ; dip it endwisc! in the water, immersing the whole of the threaded ])nrt first, and holding it still niitil the phiin jiiirt is of a V(!ry low red ; slowly iinmer.se the renininder, hnlding it still, when fully im- mersed, until it is (piite cold. 'I'lien brigliten the fiutes, and tem- ))er as follows : lleat a ])iece of tul)i! (with a bore about twice tlie <liiimeter and a length one lialf that of the tap) to a bright red lieat, lake it Croni the fire, set it iiji vertically, iind hold the taji in tin- centre of thc' tiilie, with the iijaiii puit of the i;i|i in the tuhi;
MECHANICS.
31
and the thread part projecting. Revolve it in this position suffi- cient time to heat the plain end about as warm as the hand can bear it ; then keep revolving tlie tap and moving it endwise back and forth through the tube until the thread will color to a deep brown and the shank to a brown purple. If any unevenness ap- pears in the color, hold the parts having the lighter color a little longer in the tube, or cool the part coloring too deeply by apply- ing a little oil to it. Perform the whole process slowly, taking the tap from the tube to retard it, if necessary.
Taps, Tempering. — The squares of taps should be tempered to a blue.
Taps, To temper, without springing. — Forge the tap with a little more thau the usual allowance, being careful not to heat too hot, nor to hammer too cold. After the tap is forged, heat it and hold it on one end upon the anvil. If a large one, hit it with the sledge ; if a small one, the hammer will do. During this ope- ration, the tap will give way on its weakest side and become bent. Do not attempt to straighten it. On finishing and hardening the tap, it will become perfectly straight.
Tools, Spring of. — To obviate the spring of tools which must, of necessity, be held out a long way from the tool-post, the ful- crum off which the tool springs must be adjusted so as not to stand in advance of the cutting edge of the tool. In the engraving, a represents the fulcrum off wliich the tool takes its spring ; B is the work to be cut ; and the dotted line, C, is the line in which
SFUING-TOOL.
c^
the point of the tool would spring (being in the direction denoted by the arrow), which is not in this case into' the cut, but rather
38 MECHANICS.
away from u, in consequence of the point of the tool standing back from a line perpendicular to the line of the back part of the tool, as sbovvu by the dotted line, D.
MECHANICAL SHOP-WRIXKLES AND DIRECTIONS.
ANNEAI.ING Iron and Steel. — Save the scales from the forge (oxide of iron) for this purpose.
Anvils, Tempering. — This can be done by simply heating the anvil and immersing it in a tank of cold water to a depth of two or three inches. Play a stream of water from a hose on the face.
Axles, Value of hollow.— An old apprentice of Sir William Fairbairn writes : " For several years it has cost me five dollars a week to keep the bolts on my trip or cushioned hammer-heads in repair, and, finding it to wear on my patience, I tried all kinds of iron, but to no use ; break they would. I finally bored a hole, one third the diameter of the bolts (1^ in.), and put a | in. hole down, some way below the thread, which formed a tube. I have now run them for three months, and they show no signs of giving out. The wrench used would break the other bolts easily ; but it can not do so with these. My work on spindles requires the dies to snap together about nine times in ten, which tells very severely on the bolts."
Bkxding Coi'I'EH Pipes. — Fill thorn with resin or lead, which will prevent them from buckling in the bends.
Bolts and Studs, Standing.— When these are placed in posi- tions liable to corrode them, they should have the standing ends I in. larger than the end receiving the nut, and the plain part should be square. By this means a wrench may be apj)ned to extract them when necessary. The stud, also, is not so likely to break off in consecjucncc; of weakness at the junction of the thread and the plain jjart, where the groove to relieve the terminati(m of the thread is cut.
Bolts oh Studs, Standing, To unscrew.— Studs that have be- come so corroded in their liolcs that they are liabh; to break off. should be well warmed by a red-hot washer ; becausii the strength of the stud increases ])y being hi-ated up to about 400" Fahr., and therefore studs which readily twist off when cold will unscrew when heated to about that teniperatun-. Nuts upon standing bolls of studs, in the smoke-boxes of locomotives, or in similar l)ositionH, whidi have become so corroded as to endanger twisting off, should b(! cut through on one side with a cape or cross-cut cliisel, thus saving tlie stud at the expense of the nut. The split must be cut from the end face of the nut to the bedding face.
BUAHSKS, Bedding down. — In bedding down brasses or journal- lK)xes of any description, tlie following i)lan should b<- einploycfd to gauge liow much requires to be chipped or filed away from any
MECHANICS. 39
part or parts of the bed of the brass to enable it to bed to its seat all over : Take ordinary red marking (which should be composed of Venetian-red and common oil, mixed to the consistence of a thick paint), and paint over the vrhole bed into which brass is to be fitted. Then take some putty (mixed stiffly), and rolling it into pellets about the size of a large pea, place them here and there upon the painted surface. Then drive the brass home, and drive it out again, when it will be found that the thickness to which the pellets have been smashed by the bottom of the brass registers to the greatest possible exactitude how near the bottom, of the brass comes to the bed of the bottom of the bearing, indi- cating precisely the amount to be chipped and filed ofE the bottom of the brass to bed it. It is better, however, to be careful not to take too much off at first, and to repeat the process with the pel- lets. It must be borne in mind carefully to replace the old pel- lets with new ones at each trial, otherwise you will be misled. The object of painting the bottom of the box with red marking, before placing the pellets, is to cause the latter to stick to the box and not to the brass, and to prevent them from falling out when the box is turned upside down to drive the brass out. This is the only practical method of ascertaining how much to take off a brass to' bed it, and will be found an easily applied and almost invaluable assistance.
Brasses, Fitting. — In doing this, a piece of wood must be used to hammer on in driving them in and out, since driving them with the bare hammer, a piece of metal, or a mandril, stretches the skin and enlarges the diameter across the bore ; then when the brasses are bored and the stretched skin is con- sequently removed, the brass resumes its original shape, and hence becomes loose in the strap or box. In fitting brasses to their places, leave them a little too tight, since all brasses con- tract a little across the bore in consequence of the process of boring. This rule applies also to journal-boxes of cast-iron or any other metal.
Brasses, Setting. — In setting brasses or any other journal- boxes to be bored, place a piece of sheet-tin between the joint of the brasses, and bore the brasses or boxes the thickness of the tin too large, which thickness may be gauged by placing a small piece of the same tin under the leg of the inside calipers when trying the bore. The reason for this is that practice demon- strates it to be an invariable rule that a half-circle or half-hole, whether in a movable brass or in a solid box, will never fit down upon its journal, but will bind upon the edges across the diameter, and must therefore be scraped or filed on the sides to let the crown down. This defect is obviated by the employment of the sheet-tin as described, which will save three fourths of the time usually required to fit such work to a good bearing. This plan is highly advantageous in boring eccentric straps and large brasses ; and the larger the size, the thicker the tin may be.
Brass Turnings and Filings, To melt, with little waste. — Compress in a crucible until it is full, then cover, and lute the top with pipe or fire-clay.
40 MECHAXICS.
Burr Stones. Filling holes in. — Use melted alum mixed with burr-stone pulverized to the size of grains of saud.
Burrs, To prevent heating, — Dress from centre to circum- ference, leaving no bosom. Draw a line across the centre, each way, dividing a four-foot burr into 16 squares or divisions, and other sizes, more or less, in the same proportion, with all straight furrows. Let the draft be ^ the diameter of the rock. Lay off the lands and furrows J inch each, observing to dress smooth. Sink the furrow at the eye i inch deep for corn, and run out to tV at the periphery ; for wlieat, 1% at the eye, and ^ at the peri- phery. When thus finished, crack the lands in straight lines, square with the draft of cross-lines, so as to make the lands face in the runner and bed direct. This will never heat.
Carpenter's Bench, To make a. — Take three pieces of 2 x 5 in. stuff, 3 feet long, for supports for top. Take two 12 in. boards, 13 feet long and 1 in. thick, for sides ; nail the side- boards firmly on to the ends of the 3x5 cross-pieces, and j)ut ou a top of suitable material, and you liave a bench without legs. Then take four pieces of 2x5in. stuff" of the desired height for the legs, and frame a piece 1x3 inches across each pair of legs, 6 inches from the bottom of tlie leg, putting the legs at the pro- per distance apart for width of bench. Cut a fork or slit in the toji end of each leg, s.o as to straddle the crOSs-piece at the ends ; put a 3^ X f in. bolt through each leg and the side-board, and you have a good solid bench, that can be taken down in five minutes by simply removing the four bolts. It can also be taken through any door or window, or down or up stairs, or to any place required.
Castings, Brass. — These shrink I inch to the foot in cooling.
Castings, Copper, To prevent air-holes in. — Cast in green sand, and not in dried moulds, using lA lbs. zinc as a flue, as pure copper will not run sufficiently freely to prevent honeycombing.
Castings, Copper. — These shrink i inch to the foot in cooling in the moulds, and also shrink (as do all other castings) most where there is the greatest substance of metal.
Castings, Holes in, To prevent. — In casting iron on iron or steel spindles, the moulds are cast endwise, letting the cast metal covering the spindle be an inch longer on the uppermost side than is necessary when the job is finished ; tlius the air- holes, if any, will form in the extra inch of lengtli, aud may be cut off in tlu! lathe.
Castings, Ikon. — These shrink ^ inch to the foot in cooling in the moulds.
C.\HTiNGS, Slirinkage of. — Slirinkagn sideways and endwise, on castings of 3 inches and less size, is conipensattHl for by the shake in the sand given by tlie moulder to the pattern in order to extract it from tlio mould.
Cahtin<is, Small. — In very small castings re(|uiring to be of correct size, allowance should be made in tlie pattern for tlie shako of tlie ])attern in tlu; sand, thus : A i)attern of an inch cube will refjuire to be made ^.^ inch less endwise and sideways, and
MECHANICS.
41
tlie usual allowance above an inch must be made on the top face of the pattern, which should have " top" marked on it ; thus the shake endwise and sideways given to the pattern, in order to ex- tract it without lifting the sand, will be allowed for in the size of the pattern. The effect of this shake in the sand is appreci- able in patterns tip to about four inches diameter. It is a com- mon practice to cool brass castings in order to loosen or remove the sand from the surfaces. The effect is to place conflicting strains and tensions tipon tlie whole skin of the metal, which will alter its shape when the outer skin of such faces is removed ; so that, supposing the casting to be a cube, no one face will be either true of itself or with the others when it has been planed, no matter how true the surfacing may have been performed.
Castings, Smooth. — A means highly recommended for obtain- ing very smooth castings, is mixing with the green foundry sand forming the mould about 2T) part of tar, a mixture which is em- ployed without the addition of any other substance.
Castings, To estimate the weight of. —
A pattern weighing 1 lb., and made of
Mahogany
(St. Domingo)
Maple
Beech
Cedar
Yellow Pine
White Pine
Will weisrli when cast in
|
Cast Iron. |
Zinc. |
Copper. |
Yellow Brass. |
|
8 |
8 |
10 |
9.8 |
|
10 |
9.5 |
12 |
11.5 |
|
10 |
9.8 |
12.5 |
12 |
|
11 |
11 |
14 |
13.4 |
|
11.5 |
11.4 |
14.5 |
14 |
|
13 |
12.6 |
16 |
15.5 |
|
14 |
14.5 |
18 |
17.5 |
Gun
Metal.
10
12
12.4
13.8
14.5
16
17.8
Example : The pattern of a wheel made of cedar weighs 8 lbs, how much will a casting of iron weigh 1 8 lbs. weight of pat- tern multiplied by 11.5, which is the multiplier for iron set oppo- site cedar, equals 92.0 weight of casting.
Chuck-Cement, Removing, from lathe-work. — Warm the ob- ject over a spirit-lamp, and tap lightly with a stiff brush ; the wax will adhere to the latter. If in a hurry, a few seconds' boil- ing in alcohol will remove the remainder of the wax.
Chuck-Lathe, An electric. — In order to obviate the inconve- nience and loss of time involved in the ordinary mode of fixing upon a lathe-chuck certain special kinds of work, such as thin steel disks or small circular-saws, the chuck may be converted into a temporary magnet, so that the articles, when simply placed on the face of the chuck, are held there by the attraction of the magnet ; and, when finished, can be readily detached by merely breaking the electric ctirrent and demagnetizing the chuck. The face-plate of the magnetic chuck is composed of a central core of soft iron, surrounded by an iron tube, the two being kept apart by an intermediate brass ring ; and the tube and core are each
42 MECHANICS.
surrounded by a coil of insulated copper wire, the ends of which are connected by two brass contact-rings that encircle the case containing the entire electro-magnet thus formed. These rings are grooved, and receive the ends of a pair of metal springs con- nected with the terminal wires of a battery, whereby the chuck is converted into an electro-magnet capable of holding firmly on its face the article to be turned or ground. For holding articles of larger diameter, it is found more convenient to use an ordinary face-plate, simply divided into halves by a thin brass strip across the centre ; a horseshoe-magnet, consisting of a bent bar of soft iron, with a coil of copper wire around each leg, is fixed behind the face-plate, each half of which is thus converted into one of the poles of the magnet. The whole is inclosed in a cylindrical brass casing, and two brass contact-rings, fixed around this casing, are insulated by a ring of ebonite, and are connected with the two terminal wires of the magnet-coils. A similar arrangement is also adapted for holding work upon the bed of a planing or drill- ing machine, in which case the brass contact-rings may be dis- pensed with, and any desired number of pairs of the electro-mag- netic face-plates are combined so as to form an extended surface large enough to carry large pieces of work. For exciting the electro-magnet, any ordinary battery that will produce a continu- ous current of electricity can be used.
Cocks, To grind plugs in. — The best material for this purpose is the red, well-burnt sand from the core of a brass casting, the sand being sifted, before using, through fine wire gauze. It will cut more truly and smoothly than any other material, and should be used with water, and not oil. After the cock is sufficiently ground, wash it and the barrel with clean water ; and after wip- ing them comparatively but not quite dry, revolve the plug backward and forward in its place under a slight pressure, and the surface will assume a rich Ijrown color, showing very dis- tinctly the precise nature of the fit, and leaving a smooth sur- face, free from grit and not liable to either jam or abrade. Valves may be ground to their seats in a similar manner.
Cones in Holes, Fitting. — Rub the cone with either red mark- ing or else chalk, giving it in either case a very thin coat. A narrow strip of marking, running from end of the cone, will do. Put tlie cone into its place, press it forward and revolve it back and forth, and the marks will show wlu-rc it binds.
CoNNECTiNG-KODS, Fitting. — When the cross-head and crank- pin are in their places upon the engine, fitting may b(^ done as follows : Connect the cro.ss-head end of the rod in its place upon the cross-head journal, keeping the other end clear of the crank-pin; put the l)rass('s and keys in their idaces in the rod end, then lower tlir- crank-jiin end ujion tin- crank-pin journal, which will sliow wlietlier tlie cross head journal leads true ; if it does not, move the crank-i)in end of the rod Ijack and forth, exerting a side j)rcsHure on it in the direction in wliich it wants to go, so us to ))lainlv mark where the connecting-rod brasses of the cross-head end rei|uire easing; and after th(! crossliead end is adjusted, put tlie crank-pin of the rod upon its place upon the
MECHANICS. 43
crank-pin, keeping the cross-head end clear of the cross-head ; put the brasses, keys, etc., in their places, and proceed as before. Red marking should be rubbed on both the crauk-pin and cross- head journals, so as to mark the brasses plainly. A halt-round file and half-round scraper should be used to adjust and ease the brasses.
CONNECTING-EOD STRAPS, To close the jaws of. — If the jaws are too wide at the points, rest the stra^) upon the two ends, and (with a round pene-hammer) lightly hammer the outside of the crown of the strap all over, taking care to hammer it evenly, so as not to leave any deep hammer-marks.
Connecting-rod Straps. — To open the jaws of a connecting- rod strap, hammer the inside face of the crown of the strap lightly and evenly all over with a round pene-hammer. To bring back to its original shape a strap that has been opened or closed in its width between the jaws, by being pened with a hammer, remove by filing ^^^ inch in depth of the surface that has been hammered, or heat the part hammered to a low red heat.
Connecting-rod Straps, Refitting, to rods.— Place the gib and key in the strap to prevent it from warping, and heat the crown end of the strap to a bright red ; on taking it from the fire, remove the scale by lightly filing with a coarse file ; then plunge the strap to nearly half the thickness of the crown in water, and after holding it there for about ten seconds, slowly immerse the remainder of the strap in the water, and withdraw when quite cold. It will be found to have closed along its whole length, al- though mostly at the points.
Copper or Brass, To soften. — Heat to a low red heat, and plunge in salt water.
Copper, To harden. — Copper may be slightly hardened by closing the grain. This can be done by lightly hammering its surface with a round pene-hammer.
CoRtrNDUM-WHEELS, To true. — The wheel being adjusted in the lathe, revolve it very fast, holding a piece of corundum-stone against the uneven or wabbling surface. In a short time, the piece will melt and tinite itself to the wheel, so as to make the latter perfectly true.
Cotton- Waste, To clean greasy. — Boil it in a strong solution of common soda in water, and save the resultant soapy liquid to keep your drills and reamers wet when boring iron.
Crank-pins, Riveting. — In riveting over the end of a crank- pin, apply the hammer most around the outer circumference and least toward the centre ; this will prevent the riveted end from splitting.
Emery, for grinding purposes. To prepare fine. — When no fine emery is at hand, place coarse emery upon an iron block or plate, and hammer it well with the face end of the hammer ; after which, grind it by abrasion with the hammer face.
Emery- Wheels, Speed of. — A G-inch emery-wheel should
44 MECHANICS.
make about 3400 revolutions per minute ; an S-incli, 1800 ; a 12- incU, 1200.
Engine-room Chairs. — Good chairs for engine-roona or factory use are easily made of light gas-pipe.
Grease, To clean, from bolts. — Moisten in benzine, roll in saw- dust, and brush afterward.
Grindstones, Care of. — These should never be left in the sun- lijrht, or with one side standing in water, since heat evaporates the water in the stone, leaving it harsh and hard, wliile saturation softens it. The grindstone is a self-sharpening tool ; and after being turned in one direction for some time (if a hard stone), the motion should be reversed. Sand of the right grit applied occasionally to a hard stone will improve it.
Grindstones, Selecting. — When you get a stone that suits your purpose, send a sample to the dealer to select by; a half- ounce sample is enough, and can be sent by mail.
Grindstone-Si'indles. — Common grindstone-spindles, with a crank at one end, are open to the objection that the stone will never keep round, because every person is inclined, more or less, to follow the motion of his foot with his liand, which causes the pressure on the stone to be unequal. The harder pressure is al- ways applied to the very same part of the stone, and will soon make it uneven, so that it is impossible to grind a tool true. To avoid this, put in place of the crank a small cog-wheel to the spindle, say with twelve cogs ; have another short spindle, with a crank and a cog-wheel of tliirteen cogs, to work into the former. The stone will make about 0.07 of a revolution more than tlie crank, and tlie harder pressure of the tool on the stone will change to anotlier place at every turn ; and the stone will keep perfectly round if it is a good one.
Grindstone, To true a carpenter's. — Use a J-inch bar of iron, or a gas-pipe, for a turning tool, held below the centre of the stone.
Hardening, To prevent cracking of metals wliile. — Heat the water as hot a.s bearable to the liands, dip tlie metal endwise, and immerse with the thickest part of the metal downward. When fully immersed, hold the metal still until it is quite cold.
Ikon, Cast, To harden. — Inlj gallons of clean water, mix \ i)int oil of vitriol and 2 ozs. saltpetre. Heat the iron to a cherry-red, and dip as usual.
Tuo.\, C.vst, Mixture for cast-iron cylinders, reriuiring to bo liard. — 'I'wenly pounds charcoal j>ig So. .'j, 40 lbs. Scotch pig, JJOO lbs. scrap-iron.
TuoN, Cast, Mixture for strong and clos(i-grained cast-iron for steam cylinilers, (Me. — Eighty pounds charcoal pig No. T), 100 lbs. Scotcli i)ig, and 100 lbs. 8<Tap-iron.
Ikon, M.M-i.icaiw.k. Cast, To harden. — Mix eciual parts of com- mon j)otash, saltpeln-, and Huli)hate of zinc, and use as directed for ]>ru8Hiut<! of potasli.
MECHANICS. 45
Iron Plate, To straigliten a curved. — Hammer it liglitly with a round pene-liammer ou the hollow side.
Iron Plates with true, flat surfaces. — To make a true surface- plate, it is necessary to plane up three plates, which we will term A, B, and C. First fit the faces of A and B together as nearly as possible with a smooth file (using a hardly perceptible coating of Venetian-red and common oil applied to A, to show by the marks where the faces touch). Then file C to fit A. Then try C with B ; and if they mark all over the faces, they are true, and the surfaces may be finished by the scraper, trying them re- peatedly as above. If, however, C and B should be found to fit on the edges only, it would demonstrate that A and B, though fitting, are not fiat surfaces ; but that A is hollow and B round- ing. Having corrected these defects as nearly as possible, apply B to C, again repeating the connecting process until all three sur- faces, applied interchangeably, mark evenly all over, when the surface of each will be practically true. It must, however, be borne in mind that, after rubbing the surfaces together to test them, tlie middle of each plate will (from having received the most abrasion) show the marks the plainest, so that the plates will be more nearly true if the marks show a little the plainest at and near their edges, and less plain toward the centres. The back of each plate should be planed off, care being taken that it rests evenly upon the bench, so that neither plate shall deflect from its own weight, as it would do if its weight were not sup- ported evenly upon the face resting upon the bench. The scrap- er should be used dry upon cast-iron, and kept moistened with water for steel, wrought-iron, and brass.
Iron, Eed-hot, To mark measures on.— Blacksmiths fre- quently measure a piece of iron, and put chalk-marks where they desire to cut it. The iron may then be placed in the fire and heated to a bright red without effacing the marks.
Iron, To remove hard skin from. — Hard skin on iron is due to heat and friction, and may be removed by heating to a dull red, filing the surface, and putting the iron to cool in lime or ashes.
Iron, Wrought, Contraction of. — Wrought-iron may be made to contract to a slight extent l)y heating it to a low red heat, and quenching it in water. The first operation only, however, is ef- fective. This plan is used to shorten eccentric rods, etc., to avoid getting them out of true by upsetting them with blacksmiths' tools.
Iron, Wrought, To close holes in. — If a washer or other piece of wrought-iron is a trifle too large, fill the hole and part of the outside faces with fire-clay ; heat the iron to a bright red, and plunge it in cold water. The contraction of the circumferential iron will squeeze the metal round the hole (which has been pre- vented from cooling so rapidly by the clay) inward, diminishing the size of the hole. To refit a bolt to a hole in which it has worn a trifle loose, case-harden it by the prussiate of potash pro- cess, which will increase the diameter of the bolt. If it fits into a hole of wrought-iron or steel, that too may be case-hardened, which will diminish its size, and thus refit it "to the bolt.
4fi MECHANICS.
Joints, Rubber. — In making a rubber joint, take a piece of chalk and rub it on the side of the rubber and tiange where the joint is to open ; and wlien required, they will come apart easily, and not break the rubber, although the latter may be burnt and hard. Repeat the chalking before screwing up, and you will have as good a joint as ever, and the rubber can be used a great number of times.
Keys, Driving. — Drive the key into the keyway to mark where it binds. The keyway should be oiled first, especially if the metal is cast-iron ; otherwise the surfaces are liable to seize a cut, making it very difficult to drive the keys out, and cutting ragged grooves in both the keyway and the key. The same rule applies to crank-pins and all similar work.
Keys, To make. — These should be made to fit the key ways at a . good fit on the sides without being tight, the locking being per- formed by the taper of the top and bottom, the amount of which should be about i inch per foot of length.
Keywat and Slots, To ease, Avhen hardened. — Take a strip of copper and use it as a file, applying oil and fine emery upon the surface of the work.
Lathe, Setting work on the face-plate of a. — Let the work be set out and first lightly prick-punched ; then clamp to place light- ly as near as possible, but never set the " dead-centre" against the work, for that will not bring it true ; now with a scratchawl or sharp-pointed centre, with the point resting in the prick-mark, and the other end held against or on the dead centre, revolve the work. If the point marked for the centre of the hole is out of true, the scratch-awl, or whatever rests in the point, will vibrate. Put into the lathe-rest a tool, without fastening it, and push it up to the scratch as the work is revolved, and the extent of the vibration can be seen. Tlie work can be driven as thus indicat- ed when there is no vibration of the scratch or centre, the work is perfectly set, and may be securely fastened.
Liners, Thickness of. — To ascertain the proper thickness of a liner or strip necessary to go between a pair of brasses so that (wiien the faces do not meet) the liner may be placed between theni and the brasses, when bolfeil up tight, without jamming the journal, jilace a ])iece of lead winHM't ween the brasses, and then screw thi^ caj) down tight, and the lead wir(> will comjiress, denoting the necessary thickness of liner. The latter should be made a sliade thicker than the distance the wire was compress- ed, so that the brasses may fit witliDut binding the; journal.
Links, To clos(' a (luadrant or link that has sprung or opened in liardening. — C'lamp it with bolts and plates, placing the die in tlie slot to Hup|)ort any ])art which does not require to be closed. 2'(9 open Old xlol of (I (piiidrant or link tlutl hus closed in being hardened : Take two kej-s having an e<jiiul amount of taper upon tliein, and l>lace th(!ni togeiiii-r so tlmt their outside edges are j>aral]ei. In- H<!rt ilieiM in tliiit pait of tli(^ slot which reipiires to be o])ene(l, •and Iioldiiig a liainnier auainst tin; head f)f one key <n\ one side of th*! link, driv(! in flu; other key with a luimmer on the other Hid<! of the link. After tlu^ key is driven as far in as the judg-
MECHANICS. 41
ment suggests, measure the width of the slot, so that, if the ope- ration was not performed to a sufficient extent on the first at- tempt, the operator may judge how much to essay at the second, and so on. To prevent, as fa?' as possible, a slot link or quadrant from altering its shape in the process of hardening : Fit into tlie slot, at various parts along its length, pieces of iron of the same diameter as the die intended to work in the slot, and in quench- ing the quadrant, immerse it endwise and vertically.
Nails into hard wood. To drive. — Dip in grease to assist pene- tration.
Nuts, Tight, To ease. — To ease a nut that is a little too tight upon a bolt, place it upon the bolt, and, resting it upon an iron anvil or block, strike the upper side with a hammer, turning the nut so that not more than two blows will fall upon the same face. The smaller the nut, the lighter the blows should be, and vice versa.
Nuts, Tight, To unscrew. — To start a nut that is corroded in its place, so that an ordinary wrench fails to move it, strike a few sharp blows upon its end face ; then holding a dull chisel across the chamfer of the nut, strike the chisel-head several sharp blows, which will, in a majority of cases, effect the object.
Patterns, Cast-iron. — These should have their surfaces smooth- ed, and be then slightly heated and waxed all over with the best beeswax.
Patterns for Brass Bed-Pieces. — In making a pattern for a brass bedding in a circular bed, first make the pattern at the same curve as the bed, and then pare off the centre of the crown- bed about ^- inch for every inch of diameter of bore of the brass ; the reasons for this are explained in treating of patterns for semi- octagonal bedding-brasses.
Patterns for Brasses. — In making a pattern for a brass to fit in a semi-octagonal bed such as is employed in pillar-blocks, and sometimes in the small ends of connecting-rods and axle- boxes : after having made the bed of the brass to the same shape as the seat into which it beds, take off -^ inch in brasses be- low 3 inches bore, or ^ inch in brasses above that size, from the crown face of the brass pattern, for the following reasons : The casting of iron or of brass contracts, in cooling, most at the sides, and the above is to compensate for this contraction. Fur- thermore, it will require only ^^ inch to be cut off the angles to let a brass (having bed-angles at 40°) down ^ inch on the crown ; whereas it will require ^ inch taken off the crown face to let the bed-angles down -^ inch. A strict observance of this rule will, in all cases, save one half the time required to fit such brasses to their places. In brasses whose bed-angles are more acute, a greater allowance must be made.
Patterns, To fit. — To get a pattern to fit closely over an ir- regular casting having angles, projections, or crooks in it (such as is often required to make a casting with which to patch cylin- ders or junctions of pipes), take a piece of sheet-lead, and ham- mer it lightly with a round pene-hammer, closing it round the casting until it will, by stretching where it is requisite, conform
48 MECHANICS.
strictly to the sliape of the surface, however irregular it may be. The moulder can then cast a patch from the sheet-lead, making it of any required thickness.
Patterns, Wooden. — These should never be left in the foun- dry, where they are liable to warp from the excessive range of temperature.
Pening, Setting work by. — The operation termed "pening," is stretching the skin on one side of work to alter its shape, the principle of which is that, by striking the face of the metal with a hammer, the face of the metal struck stretches, and tends to force the work in a circular form, of which the part receiving the effect of the hammer is the outside circle or diameter. The engraving represents a piece of
a
I.,.- at
:r
\,^-'
a
flat iron, which would, if it were well hammered on the face, a a a, with the pene of a hammer, alter its form to that de- noted by the dotted lines. Or let the rod, (/, shown below be attached to a double eye at one end, the other end requiring to come fair witli the double eye, 6, at the other end ; then, if it is pened perpendicularly on the face, c, of the rod, the stretched skin will throw the end around so that it will come fair with the
xa
eye, 6. Connecting-rod straps which are a little too wide for the rod ends may be in like manner closed so as to fit by pening the outside of the ciown end, or, if too narrow, may be opened by pening the inside of the crown end ; l)ut in either case, the ends of the strap alter most in consequence of their lengths, and the strap will require refitting between its jaws.
Pipes, Gas or Steam, Threads used in screwing : Inside diameter. Tlircads Inside diamctor. TIni-ads
per inch. I'er inch.
lU
111 8
8 8 8
_ insid(Mlianictersare
only estimated. aVtlii'V vary for jjiljes of different strength, the
|
i |
27 |
lA |
||
|
i |
18 |
2 |
||
|
1 |
18 |
2i |
||
|
\ |
14 |
3 |
||
|
\ |
14 |
3i |
||
|
1 u |
lU lA |
4 |
||
|
Taper of threads |
A |
per inch f |
)f 1 |
pngtli. Thes |
MECHANICS.
49
thickness varying for the different grades, and the outside diame- ter remaining the same.
PiSTOX-RiNGS, To open. — Hammer them lightly with a round pene-hammer all round their inside faces.
PiSTOX-RoD Glands. — If these are rather tight, the piston-rod may be eased bv rubbing the gland up and do%vn the rod, and giy'ing it at the 'same time a revolving motion back and forth at each stroke. Oil must be supplied to the rod to prevent the gland from seizing or cutting. A gland should be chucked in the lathe by the tlange, so that the bore and outside diameter may be turned at one chucking, and thus be true without depending upon the truth of a mandrel.
Plaster, Inserting screws in. — Make a large hole in the plas- ter and drive in a wooden plug, in which insert the screw. The plug may be first split and a groove cut in each half.
Pullets, Turning. — Pulleys should be turned either on a man- drel, or else chucked by the arms, since chucking them by the rims springs them out of true.
PuNXHiNG Metals. — The same elements of resistance enter into the operation of punching as in that of shearing. In short, a punch and die may be considered as shears with circular blades. The coefficient of pressure in punching, for any given area of section, will be exactly that for shearing the same area of sec-
I
P
J
iff
SHKENKING METAl-WORK.
tion, without reference to the thickness of the material. The measure of force necessary to effect the various punchings readi- ly gives the value of the resistance to shearing in cases of ordi- nary metals. This resistance, per square foot, is determined to be, in lbs. : For lead. 392,548 : block-tin, 450.784 : nl'ov of lead and tin, 731,176 ; zinc, 1,843,136 ; copper, 4,083,941 ; iron, 103,-
ooo.
50 MECHANICS.
Reducing the Size of Work by shrinking with Fire AND Water. — For reducing the isize of wrought-iron work, the process shown in the following engraving may be employed. a a is the section of a wrought-iron square box or tube, which is supposed to be made red hot and placed suddenly in the water, B, from its end, C, to the point D ; the result is that the metal in the water, from C to D, contracts or shrinks in diameter, and com- presses the hot metal immediately above the water-line, as the small cone at D denotes. If then the box or tube is slowly im- mersed in the water, its form, when cold, will be as in the right- hand figure, that part from C to D maintaining its original size, and the remainder being smaller.
It must then be reheated and suddenly immersed from the end, E, nearly to D, until it is cold, and then slowly lowered in the water, as before, which will contract the part from D to C, mak- ing the entire length parallel but smaller, both in diameter and bore, than before it was thus operated upon.
Rolls, To prevent cinders getting between the necks of. — Bore grooves out of the bearings, 1^ inches wide and 4 inch deep and 1^ inches apart, put them at an angle of 45° with the face of the brass, and fill up said grooves with soft Babbitt metal. Then when cinder or iron gets in, it will travel but a short distance be- fore it reaches the soft metal, and the motion of the roll will im- bed it therein so that it can not protrude and scoi-e the neck, as it would were it to stick in the brass.
Rust, To remove, from small hollow castings. — Dip in dilute sulphuric acid 1 part commercial acid to 10 water ; wash in hot lime-water, and dry in the tumbler with dry sawdust.
Sands and Facings for Castings. — For castings, such as pipes or small cylinders, fine sand, termed No. 1, is used, the fac- ing Ijcing ])liinibago. A good facing for loam castings is made of 1 part VVhitehead sand to 3 parts fire-sand. For very fine-faced castings, Albany or Waterford sand is unsurpassed. Another facing for fine castings is 1 part of sea-coal to 8 or 10 of AUmny sand : for heavy castings, however, 1 to 5 will answer
Saw'-Bladks, Snuill. — Mechanics who want small gig saw blades will find that the steel springs of which hoopskirts are formed will make; caijital ones of any lengths; and they vary in width, so as to l)e suitable for a variety of uses.
ScRKW-DuiVKKS, The advantage of long. — The reason that a screw is driven more easily into wood l)y a long than by a short Hcrew-driver, is that the tool is held at an angle, and coiisc<|UiMitly the long Hcrew-di-ivcr aiTonls a greater leverage than a short one. If both were st^ciircd ?;(> as to Ix- at right angles to the face of the screw, there would ije no difference in their action.
SciiRWH, To prevent, getting tight in their nuts. — Plane a key- way or groove in tin; screw, .< in. wide, the full length of the scresv and down to the bottom of the tlireads ; and it will act like a tap, and scrape all tlie hard gummy grease out of the. nut, and always keej) it clean and working free.
ScuKW and Hrad Holes in finisiikd wouk, 'I'o plug. — Ohio tlie edge of tlie plug ; |(Ut, no glut- in the hole. By this means
MECHANICS.
61
the surplus glue is left on tlie surface, and if the plug does not hit the screw, it will seldom show. Set the heads of brads well in, then pass a sponge of hot water over them, filling the holes with hot water. This brings tlie wood more to its natural posi- tion, and closes by degrees over the head of the plug. When dry, sandpaper off and paint, and the putty will not hit the head of the brad.
Screws, Hints about. — When screws are driven into soft wood and subjected to considerable strain, they are likely to work loose ; in such case, dip tlie screw in thick glue before insertino-. When buying screws, see that the heads are round and well cut ; that there are no flaws in the body or thread part, and that they have gimlet points. A screw of good make will drive into oak as easy as others into pine, and will endure having twice the force brought against it. W^hen there is an article of furniture to be hastily repaired, and no glue is handy, insert a stick a little les.s in size than the hole for the screw and fill the rest of the cavity with powdered resin ; heat the screw sufficiently to meet the resin as it is driven in.
Screw, To remove. — An obdurate screw may sometimes be drawn by applying a piece of red-hot iron to the head for a minute or two, and immediately using the screw-driver.
Screw-Threads. — English and American proportions :
TJie Whitworth Thread.
Diameter in inches.... A i A I I'iT * I f I 1
Threads per inch 21 30 18 16 14 12 11 10 9 8
Diameter in inches li IJ If 1* If If 1^ 2 2i 2i
Threads per inch 7766554^4^44
Diameter in inches... 2f 3 3i 34^ 3| 4 4^- 4i 4f 5 Threads per inch 3^ 3i 3i 3i 3 3 2f 2| 2f 2f
Diameter in inches. .. . 5 J 5^ 5f 6 Threads per inch 2f 2f 2i 2i
Angle of threads = 55°. Depth of threads = pitch of screws. (One sixth of the depth is rounded off at top and bottom.) Number of threads to the inch in square threads = 4 number of those in angular threads.
Standard American Proportions.
Diameter in inches i ^ I tV i iir I f I 1
Threads per inch 20 18 16 14 13 12 11 10 9 8
Diameter in inches If IJ If U If If If 2 2i 2f
Threads per inch 7 7 6 6 5f5 5 4f4f4
Diameter in inches 2i 3 3i 3i 3f 4 4f 4f 4f 5
Threads per inch 4 3f 3i 3i 3 3 2f 2f 2f 2f
Diameter in inches . . . 5J 5f Sf 6 Threads per inch 2f 2| 2f 2i
Angle of threads = 60'. Flat surface at top and bottom = f of the pitch. For rough bolts, the distance between parallel sides
52 MBCHANICS.
of bolt-head and nut = 1^ diameters of bolt + ^ of an inch. Thick- ness of head = i distance between parallel sides. Thickness of nut = diameter of bolt. In finished bolts, thickness of head = thickness of nut. Distance between parallel sides of a bolt-head and nut and thickness of nut is -j\- of an inch less for finished work than for rough.
Softening Bright Work without damaging the Finish. — Place tlie pieces in an iron box, and fill in the interstices with iron turnings ; close the box, lute the cracks witli fire-clay, and heat to a red, allowing the box to cool as slowly as possible. It is a good plan to let the furnace-fires go out and leave the box in the furnace to cool.
Solder, To flow. — Ordinary solder, 2 parts tin and 1 part lead, will flow smoothly on tin when dipped by previously putting sal- ammoniac on the surface to be tinned.
Spirit-Leyel, Accuracy of the. — The best length of bubble depends on the length or curvature of the tube, a short bubble being required for u tube with a small radius of curvature, and increasing regularly in proportion with the increase of the radius of curvature.
Springs, Steel. — To find elasticity of a given steel-plate spring: Breadth of plate in inches multiplied by cube of the thickness in V,; in., and by number of plates. Divide cube of span in inches by l)roduct so found, and multiply by l.GO. Result, equal elasticity in -^ in. per ton of load. To find span due to a given eladicity and number and size of plate : Multiply elasticity in sixteenths per ton by breadth ol plate in inches, and divide by cube of the thickness in inches, and by number of plates ; divide by 1.G6, and find cube-root of quotient. Result, e(iual span in inches. To find num- ber of plates due to a given elasticiti/, span, and size of jdates : Multii)ly the cube of the span iu inches by 1.G6. Multiply the elasticity in sixteenths by the breadth of the plate in inches, and by the cube of the thickness in sixteenths ; divide the former ])roduct by the latter. The (juotient is tlie number of plates. To find the working xtnngth of k given steel-plate spring : Mul- tiply the breadth of plate in inches by the square of the thick- ness in sixteenths, and by the number of plates. Multiply also the working span in inches by 11.:} ; dividt* the former product by the latter. Result, equal workiug strength in tons burden. To find sptin due to a ginrn. Ktn ngtii and nunibrr and xize of plate : Multiply tlie breadth of ])late in inches by the square of the tiiickness in sixteenths, and liy the nm.iber of ])latea ; multiply also tlie strengtli in tons by 11.3 ; divide the former prcaict by the latter. Result, e(|ual working span in inche.s. To find the numher of pbttes due to a girc/i ntnngtli, sp • and size of plate : M ''iply till' strength in tons by sjjan in h .'S, and (livide l)y 1 • muliiply also the ijrcadlh of jdatt; in iii.-.i'S by tlu; scpiaro
of tlie thickiirss in sixteeiitliB ; divide the former product by the latter. |{esult, ecpial nuiiilier of jilates. The span is that due to tlie form of the spring loaded. Extra thick jilates must be re- placed by an equivalent number of plates of the ruling tliickness
MECHANICS. 53
before applying the rule. To find this, multiply the number of extra plates by the square of their thickness, and divide by the square of the rulins: thickness ; conversely, tlie number of plates of the ruling thickness to be removed for a given number of extra plates may be found in the same way
Springs, To reduce elasticity of. — A well-tempered bar-spring will lose much of its elastic strength by filing off a very thin scale from the surface.
Steel, Advantage of holes drilled iu. — The advantage in tensile strength, when holes are drilled in steel rather than punched, is 25.5 per cent.
Steel, Cast, To weld. — Apply powdered borax to the weld while heating it in the fire. If the steel is made too hot, it will crack during the hammering process.
Steel, Cast, Welding compound for. — Mix i lb. saltpetre aud I lb. oil of vitriol in 2 gallons hard water ; heat the steel to a blood red, and coo! in the mixture before welding. Then reheat, in sand, and weld by hammering as usual.
Steel, Fire for tempering. — In hardening and tempering steel, a clean charcoal, anthracite, or coked bituminous coal fire is re- quired ; such as is fit for taking a forging heat on iron is entirely uufit for hardening purposes. The sulphur contained in the coal combines with the steel to form sulphuret of iron, and ruins its texture.
Steel, Tempering. — The colors shown at different temperatures Fahr. are as follows: Very pale yellowish, 430" ; pale straw, 450° ; vellow, 470° ; brown, 490° ; mottled brown, 510° ; purple, 530° ; bright blue, 550° ; blue, 560° ; dark blue, 600°.
Steel, To demagnetize. — (1) Heat it to a red heat, and allow it to cool slowly. (2) Place the steel on a magnet, with the same poles touching the same poles of the magnet, and repeat tlie operation tili total demagnetization has taken place.
Steel, To remove blue color from. — (1) Use 1 part oil of vitriol to 10 parts water. (2) Dip the articles in a strong solution of cyanide of potassium nearly boiling. (3) Dip the article in hy- drochloric acid, and quickly rinse in clean water.
Tempering steel for drilling rock.— Be careful not to overheat it in hardening and forging, and quench in salt water, drawing to a brown color.
Tempering, The color-tests for.— Says Mr. J. Richards : " Pro- cure eight pieces of cast-steel, about 2 in. long by 1 in. wide, and f of an inch thick ; heat them to a high red heat, and drop them into a salt-bath. Leave one without tempering, to show the white shade of extreme hardness, and grind off and polish one side of each of the remaining seven pieces. Then give them to an experienced tool-maker to be drawn to seven various shades of temper, ranging from the white piece to the dark blue color of soft steel. On'the backs of these pieces paste labels, describing the technical name of the shades and the general uses to which tools of corresponding liardn(>ss are adajited. This will form an
54 MECHANICS.
interesting collection of specimens, and accustom the fye to the various tints, whicli will, after some experience, be instantly re- cognized when seen separately."
Tinning small castings. — Clean, and boil them with scraps of block-tin in a solution of cream of tartar.
Water-wheel, Steps for. — No step or foot-bearing of metal is equal to one of good oak or rock-maple.
Zinc, Stamping. — In stam]iing sheet-zinc in dies, much waste occurs from the small difEerence between the melting-point and the temperature at which sheet-zinc should be stamped to get the best effect. To obviate this waste, heat the zinc by dipping in oil at the proper temperature.
ENGINEERING.
TESTIXG THE STRENGTH OF MATERIALS
BY PROF. R. H. THURSTOX.
The engraving whicli accompanies this article illustrates a very convenient, yet quite accurate, method of determining the strength of materials, whicli has been devised by the writer. The test-piece is made by catting, from the piece of metal of which the strength is to be determined, a piece about 3 in.
TESTING METAXS.
long and 1 in. square. At the middle of its length, a part is turned cylindrical in form and 1 in. long, with a diameter of + in. if of iron, or 'i in. if the metal is steel. The test-piece thus made is fastened in the vise, as shown in the engraving, and a long- handled wrench is attached to the projecting head. A spring-
OO SC^'GINEEKING.
balance is secured to the end of this wrench, and the experimen- ter twists off the head by pulling on this sprinj.r-balauce, as seen in the illustration. The" balance should be capable of indicating weights of fifty pounas or more. By simply painting the scale of the balance with white-lead, or smearing it with tallow, and by springing the pointer so that it will touch the surface, a re- cording apparatus may be improvised which will indicate the maximum strain reached during the test.
In testing, the experimenter i)ulls steadily on the balance, gra- dually increasing the force exerted, and watching carefully, and noting the action of, the test-piece and the balance, until fracture occurs. A resistance, which is apparently quite unyielding, is ft'lt at first ; this is suddenly observed to be succeeded by a grad- ually increasing distortion of the test-piece, accompanied by an increasing resistance, up to the point of the commencement of rupture. From the latter point, the resistance becomes less and less, finally ceasing when the test-piece fails apart. By conduct- ing the operation very carefirily, and noting resistances very accu- rately, all of the following important points may be determined :
The limit of elasticity is the point at which the yielding first commences. Note the reading of the balance at this point and the angle of distortion. The last quantity is the measure of the stiffness of the metal. The most rigid pieces are, of course, those which yield the least with a given amount of force. After the piece has been twisted so far as to have taken a set, the pull may be relaxed, and the distance which the piece springs back is to be noted. The elaKticity of the metal is measured by this recoil. The ductility of the metal is measured by the extent of yielding which occurs before fracture takes place. The rexiliencc of the metal — which is the name given its power of resisting shock — is very closely proportioned to its strength multiplied by its ductili- ty. Therefore, to ascertain what blow would be resisted by it without its taking a set, it is simidy necessary to multij)ly the re- sistance at the limit of elasticity by the amount of distortion ob- served within the elastic limit. The hom<>(j( neity of the material is indicated by the smoothness and regularity with which the metal changes in its power of resistance as the deformation pro- gresses.
In making such a series of experiments, it is usually found be.st to first select a well-known and good brand of the kind of metal which it is i)roposed to test, and, by a set of exi)erinu'iits on test-pieces cut from it, to determine what, with the particular arrangement of aj^paratus chosen, is the resistance registered by the l)alance, and what are the characteristics of the metal as shown by the method here described. By a careful comi)arison of the behavior of tlie metal of which the <iuality is desired to be learned with tliis .standard set of satnides, tlie operator soon learns to judge cpiickly and accurately of the value of his mate- rial for any specified purpose.
Ah the tensile strength of a metal is usually very closely pro- IK)rtional to tlie resistance to torsion, this also enables a very sa- tisfactory deteriuinalion of the value of the metJil for resisting tension to be obtaini'd. In tht^ autographic recording nuichine, built by the Meclianical Laboratory of the Stevens Institute of
ENGINEERING. 57
Technolooy, these results are permanently inscribed upon a sheet of profile-paper, the pencil of the ajiparatus writing a diagram or curve which is a record of all the circumstances modifying the re- sisting power of the metal while under test. The rule being ap- plied, the torsional, and approximately the tensile, resistance is read off at a glance, and tlie position of the elastic limit, the ho- mogeneousness, the elasticity, the stiffness, the ductility, the resilience, are all found fully indicated by the diagram, and can be, at any subsequent period, shown by means of this automati- cally produced record. On these records, the tensile resistance is louud to be about 25,000 pounds per square inch for each inch in height of the diagram.
The peculiar method of fracture here adopted is well adapted to exhibit in the surfaces of the break any peculiarity of the metal. If homogeneous, it will show a uniform and characteris- tic fracture ; if seamy, it will be found to have cracks extending spirally around it ; if of cast-iron, the character of the ruptured surfaces will at once reveal to the experienced eye whether the metal is fine or coarse grained, a dark foundry or a light forge iron, and whether of close or open texture. If of steel, it will be readily seen whether it is " high" or " low," whether tool steel or of the machinery grade. Whatever the character of the ma- terial, the eye, experienced in such kinds of observation, will at once detect it, while the record of the experiment, or the " strain- diagram," will give the exact data of resistances, and will be a check upon the judgment thus formed.
THE ENGINE AND ITS APPENDAGES.
COXDENSERS, Gain from the application of, to steam-engines. — In the early days of the steam-engine, very low pressure was or- dinarily employed for engines with condensers, while, on the con- trary, what was considered a very high pressure was adopted for engines that exhausted into the atmosphere. Hence arose the terms high and low pressure engines, the former being engines with, and the latter without, condensers. At present, a high pressure of steam is ordinarily carried in both kinds of engines, so that the terms do not describe the two varieties as well as formerly. Many engineers prefer to class engines as condensing and non-condensing, rather than as high and low pressure ; and this classification is generally considered the more correct of the two. One who regards economy puts in a condensing engine, if he has plenty of water in the locality ; and many old non-con- densing engines are being fitted with condensers, under the more enlightened engineering practice of the present time.
It may be fairly assumed that a non-condensing engine has, on an average, at least 2 lbs. per square inch back pressure on the piston. By the application of a condenser, it might be expected
58 Ei«fGINEERi:NG.
tliat there would be a negative pressure of 10 lbs. per- sq. inch on the back of the piston, so that the piston pressure would be in- creased bj 12 lbs. In this assumption, an allowance is made for the power required to work the air-pump, and the engine is sup- posed to be at least 7o horse-power. For an engine smaller than this, it would be better to allow an increase in the positive pressure of not more than 10 lbs. per square inch. As the condenser, by decreasing the back pressure on the piston, adds just as much to the positive pressure, it is plain that a lower pressure of steam can be used, or the steam may be cut off at an earlier point of the stroke. The gain in either case can be a})])roximately calculated. If the gain in positive pressure produced by the reduction in back pressure be multiplied by 100, and divided by the mean ef- fective pressure on the piston, it will give the percentage of gain in pressure due to the condenser.
Thus, if the mean effective pressure on the piston is 30 lbs. per square inch, the gain in pressure will be 100 times 12, or 1200, divided l)y 30, which is 40 per cent. Now suppose that before the condenser was attached, tiie steam was cut off in the cylin- der at half stroke ; under the new conditions the required mean effective pressure can be obtained with a lower boiler pressure than before. Before the condenser was in use, it would be ne- cessary to maintain a pressure in the boiler of about 58 lbs. per square inch by gauge, to give a mean effective pressure of 30 lbs. on the piston ; while with an increase of 12 lbs. in the effective pressure, by the application of the condenser, a boiler pressure of about 39 lbs. would suffice. As the weight of steam \>eT cubic foot at 58 lbs. pressure is 0.17481 lbs., and only 0.132 lbs. at 3i» lbs. pressure, there would be a saving of about 24.5 jier cent in the amount of steam reijuired to run the engine. Instead of re- ducing the steam pressure after attaching a condenser to an en- gine, it might be better to maintain the same pressure in the boiler, and cut off the steam at an earlier ])art of the stroke. In the case under consideration, tlie increase in 12 lbs. of the effec- tive pressure would permit of closing tlie steam port a little be- fore the completion of one third of the stroke ; and supposing tliat the clearance space in the cylinder amounts to 5 i>er cent of the capacity of till- (-ylindcr, the (juantifics of steam recpiiri'd ])er stroke, before and after tlie use of tlie condenser, would be in the ratio of 550 to 303, so that there would be a saving of 34 per cent.
The example given represents a case in ordinary practice. By varying the data, of rour.se a greater or less amount of saving would re.suh ; but with an engine in good condition, it is gene- rally saf(^ to estimate that a saving from 20 to 25 ])er cent of the amount of steam usc-d, and, coiise(iuently, of the consumption of coal, will be realized by tlu^ application of a condenser. Indeed, it is not unusual for manufacturers to guarantt^e this amount of saving in converting a non-condensing into a condensing engine.
B.
f^OTTON Machinkuy, Power required Id drive. — The following are fair a|)proxi mate rules : Cotton openers, I liorse-power per l(MH) lbs. cotton delivered. Cotton jiickers, 3 liorse-|)ower per 1000 lbs. <:otton delivered. Cotton canis, v'n horse ])ower per lb.
ENGIXEERI]S'G. 59
cotton delivered per day, and, at 125 revolutions per minute, 0.13|- liorse-power. Cotton cards, best practice, -^ horse-power per revolution per minute. Railway heads, breakers, 1 horse-power per each 10 yards per miuute. Railway heads, finishers, 0.001 horse-power "per revolution per minnte. Drawiug-frames, 0.003 horse-power per revolution per minute. Spindles, 0.005 horse- power per spindle per 1000 revolutions. Damp weather adds 10 or 13 per cent ; methods of banding may make equally great variations. Looms require from 0.1 to 0.35 horse-power each. Pickers take 4 to 6 horse-power. Cloth shears from 3 to 4 horse- power.
Cylinders, Balancing heavy. — The cylinder, being keyed upon its axle as it is intended to run, is lifted by a tackle or crane, and lowered so that each of its journals rests upon a stout steel straight-edge placed so that its upper surface is exactly level and parallel with its fellow. These straight-edges should not only be so rigid as to suffer no sensible deflection from the weight of the cylinder, but they should be very hard and smooth, and great care should be taken to keep them free from indentations. The journals of the cylinder must also be round and polished. The cylinder can now be loaded on its lighter side, or vice versa, until it will remain perfectly motionless when stopped in any part of its revolution.
Cylinders, Locomotive, Placing in line. — To test the ac- curacy of the work after the bed-piece has been permanently fixed to the boiler, clamp a cylinder to its seat on the bed-piece, and fit a wooden cross (with a pin-hole through its centre) to the bore of the cylinder at its front end ; then pass a fine strong line through the hole, and extend it back so that it shall occupy a point ex- actly at the intersection of the central line of the driver-axle with the vertical plane of motion of the centre of the crank-pin and connecting-rod ; draw the line taut and fasten it in this posi- tion ; then apply callipers or a gauge at the rear end of the cylin- der, between the surface of the bore and the line, above and be- low and right and left of the line ; and if the cylinder is in line, the four distances will of course be exactly the same. It is essen- tial that the tAvo horizontal distances should coincide exactly, and that the central lines of the two cylinders of a locomotive should be exactly parallel with each other, but for obvious reasons the exact coincidence of the two vertical distances is not essential to the efficiency or correct Avorking of the engine.
Instead of a Avooden cross, as aboA'e mentioned, a more conve- nient instrument, made of metal, may be proA^ided, consisting of four bevel gears. A, which serve also as nuts, which work tour sockets, B, with threads cut on their inner ends, all neatly fitted to a light casting, E, haA'ing a fine central hole for the line, as shown. A central gear, C, Avorks the four gears, of course all at the same time. SeA-eral sets of steel rods, D, may be provided if necessary, of different lengths, and thus render the instrument universal in its application, each set of rods serving for cylinders varying tAVO inches, more or less, in the diameters of their bores.
To determine whether a cylinder of an old engine is in line : Remove the front head of the cylinder, the piston, the stuffing-
LiO
KNGINKKKIXG.
box gland, and the tro^s-head ; apply the cross and line, as above directed, extendiufj the line through the piston-rod hole in the rear head to a point exactly central with the crank-pin when the crank is at its dead point ; draw tlie line taut, and, it the cylinder
rl.ACINO LOCOMOTIVE CVLlNXJEItS IN l.l.NE.
is correctly in range, the line will occupy a central position in the stuffing-box, which maybe determined as before directed. If the cross-head guides are parallel with the line, both vertically and laterally, they are also correct.
C'VLIXDKUS, Thick. — Thick cylinders are those in which the thickness is considerable in comjjarison with the internal dianu'- ter. To find tlu; bursting ])ressure of a thick cylinder, take the j)ro- ductof (1) tlie trnacityof tin; nuiterial in ixjuihIs per scjuare inch, and (2) tli(! tliickness of the cylinder in indies, and divide the ])ro- duct Ity th<^ sum of (1) the thickness in inches, and (2) the internal radius of the cylinder in inclu-s. Tints u cylin<ler with an internal radius of 4 indies, and a thickness of 5 iiu-hes, if made of cast- iron having a tensile strength of Ki, ()()() lbs. ])er 8(juare inch, lias a biir.-tin;^ jjre.ssure of HHHH.'J lbs., Ibis being the product of 10,000 and 5, divided by tlie sum of 4 and 5. B.
FInoinkku, Duties of the. — The ordinary daily duties of an en- gineer are as follows : On coming in \]ir morning, he sliould first ascertain the amount of water in tin; l>oiler ; and, if tbat is all right, j)roceed to raisi- steam, eifber cleaning and si)rea(ling tlie
ENGINEERING. 61
fire, if it has been banked, or making it up, if it has been hauled. A fire is kindled in the boiler in essentially the same manner as in a stove, wood and sliaviugs first being ignited, and then cover- ed with coal. In starting the fire, it is a good plan to cover the back of the grate with coal, to prevent the passage of cold air through the tubes. In getting up steam, the safety-valve should be raised a little, to permit the escape of air from the boiler. Having got the fire under way, the engineer should wipe off the engine, fill the oil-cups, and make any adjustments that may be necessary, such as tightening keys and screwing up joints or glands of stuffing-boxes, and shotild see that the cylinder-cocks are open. When steam is raised, he shotild open the stop-valve and start the engine ; after which, if a part of his duty is to at- tend to the shafting, he should examine and oil it. Then he should get out the ashes, provide a supply of coal, and screen it, if necessary, and proceed to make everything tidy around the en- gine and boiler. Throughout the daj', he should keep a watchful eye on the fire, the water, the steam, and the engine. In manag- ing the fire, care should be taken to have the furnace-door open as little as possible ; and, if steam is formed too rapidly, the fire should be regulated by closing the damper and ash-pit doors. In regulating the height of the water, it is a good plan to keep a steady feed, and maintain the height constant. If it is found that the water is falling, the engineer should discover whether it is caused by a leak, or by the refusal of the pump to work. He can tell whether the pump is working by the sound of the check- valve falling after each stroke, or by feeling the feed-pipe or check-valve. A pump will not feed when the temperature of the water is very high, unless it is specially adapted for pumping hot water ; and if it refuses to work from this cause, the temperature of the water should be reduced. A pump will not deliver water if the proper valves are not opened, if its passages are choked, or if its packing is defective. It would be necessary to examine the pump at once, and endeavor to discover and remedy the difficulty. If the water falls in the boiler on account of a leak, it can some- times be temporarily repaired with a plug, or the pump can be run faster, so as to keep up the water until stopping-time. If this is not possible, the fire should be hauled, and the engine al- lowed to ran as long as there is sufficient steam -pressure. In case the engineer finds that the pump is not feeding, and he has a fair supply of water in the boiler, he should at once examine the pump, and endeavor to remedy the trouble without stopping the engine. If he does not succeed, however, before the water falls below the level of the lowest gauge-cock, he should haul the fire, and let the engine run as long as the steam-pressure is sufficient. If he has been called away from the boiler, and on his return finds that the water is below the level of the lower gauge-cock, he should imme- diately ascertain the steam-pressure, and if it is rising rapidly he should haul the fire at once. If the steam-pressure is about the same as usual, he should examine the pump ; and if it is not de- livering water, he should haul the fire. If the pump is feeding, he may run it faster, watching the steam-gauge carefully. If the pressure does not fall, he should stop the pump and haul the fire. In any case the engine should not be stopped until the steam-
62 ENGINEERING.
]iressiire is considerably reduced. The engineer should ho very l):irticular, on findhig the water low, to examine the steam-gauge at once ; and if the pressure is unusually high, he should haul the fire without delay.
A boiler foams or primes either because it has insufficient steam room, or on account of dirt or grease in the boiler or the feed-water. The trouble is often experienced with new boilers, and disappears w'hen they become clean. Priming is dangerous, if much water is carried over with the steam, as it is difficult to maintain the water-level constant, and the engine is liable to be broken by the water in the cylinders. If the trouble is caused by insufficient steam-room, it can sometimes be partially over- come \)y increasing the steam pressure, and throttling it down to the ordinary working pressure in the cylinder ; but the only ef- fectual way is to provide more steam-room. If the priming is due to dirt or grease in the boiler, the engineer should blow off frequently, and clean the boiler every few days. In lilowing off, it is well to raise the water-level in the boiler by putting on a strong feed, and then blow down below the level that is ordi- narily maintained. It is very often the case that the water-level is higher when the engine is running than it is when none of the steam is being used. The engineer should ascertain how much higher the water rises in such a case, so as to have a ])ro- per quantity of water when the engine is stopped. B.
Engine for a row-boat. — For an ordinary Wliitiliull row-boat, 18 feet long, to run at a si)eed of 8 miles per hour, the engiiu> should have two cylinders, 2 in. diamt^t(!r and 8 in. stroke ; tubular boiler, 24 to 2S iu'-h(;s iu diameter, 4 feet high ; propeller, 22 to 24 inches in diameter, with ',i feet pitch.
Engines and Boii-eus, Small. — By the aid of the accompany- ing table, the effective horse-power (that available^ for useful work) of small engines can b(! approximately determined. The tal)le is designed for non-cond(!nsing engines, with cylinders uj) U) G inches in diiuneter, and for piston-s|)eeds u]) to 400 feet a mi- nute ; the connection of the engine witli tlie boiler being sup- posed to be tolerably direct, tlu^ ]>ortsand pipes heing of siitli<'ient sizes, and tlie steam-valve closing wiien tiie piston has nuide three <|uarter3 of the stroke. As the tabh; is designed for avcrnf/c conditions, it is evident that it wiil give rc^sult.s that are too large in som<! casf'H, and too small in othei's.
/. — To find the linrKC-ixxncr of itii iiif/iiie rornxjiiiiKliii;/ to a (jlrcii, dunneter of fiflindi r, Iciujth <f MroliC, inniiher of rei'oli/tioiix per minute, and pirKsure of steam in tlie boiler. (1) Multijily the length of strokt! in inches by the number of revolutions i)erjninute, and divider the ])roduct by (>. Tin^ result is the ]>iston-8]>eed in fret per minute;. (2) Find tin; nuniluT in the table the nearest to the given Hteam-]iressure anil calculatiHl ])iston-s])eeii, and multiidy it by 0.7804 times the sipiaro of the diann'ter of the pis- ton in in(;hes. Krample: An engine has a cylinder 2 inclics in diainetiip, and a lenjrlh of stroke of 2 inclies. It makes 400 revo- lutifins a minute, imd the boiler pressure is 50 pounds jier sfpian; inch. Alls.: 'I'wice 400 is HOO. ,S((0 ilivhled by (lis \:V.',k. t'le piston- Hpeed in feet per minute. (I!) 'I'lie nearest piston-speed iu lablo
ENGINEKBING.
63
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64
ENGINEERING.
is 130 feet, and the number in table corresponding to speed of 100 and pressure of 50, is 0.074 ; the number for speed of 30 and same pressure is 0.022 ; required number is sum of 0.074 and 0.022, or 0.096, corresponding to speed of 130 and pressure of 50. The pro- duct of 4 and 0.7854 is 3.1416, and the product of 0.096 and 3.1416, or the required horse-power, is 0.3-|-.
//. — Dlnineter in inches of cylinder required for a gicoi horse- power, piston-speed, and boiler-pressure. (1) Find in the table the number nearest to the given piston speed and steam-pressure. (2) Multiply the number obtained in (1) by 0.7854. (3) Divide the given horse-power by the quantity obtained iu (2). (4) Take the square root of the quantity obtained in (3).
Exdmple. — What should be the diameter of cylinder of an engine developing 2 horse-power, with a piston-speed of 150 feet a minute, and a boiler-pressure of 100 pounds per square inch V (1) The number from the table is the sum of 0.161 and 0.081, or 0.242. (2) Tlie i)roduct of 0.242 and 0.7854 is 0.1900()(iS. (3) The quotient of 2 divided by 0.1900668, is about 10.5226 (4) The square root of 10.5226 is 3.244-, or about 3J inches, the re- quired diameter of cylinder. '
III. — The number of pounds of water required to be ewiporaled per hour for each Jiorse-poiper exerted, and for various boiler-pressures, may be approximately estimated from the accompanying table.
|
Pressure of |
Pounds of |
Pressure of |
Pounds of |
|
steam in |
vattT per |
steiini ill |
water per |
|
boiler by |
ett'ective |
boiler by |
cftective |
|
gauge. |
horsu-power |
gauge. |
horse-power |
|
pur hour. |
per hour, |
||
|
10 |
118 |
60 |
75 |
|
15 |
Ill |
70 |
71 |
|
20 |
105 |
80 |
68 |
|
25 |
100 |
90 |
65 |
|
30 |
93 |
100 |
63 |
|
40 |
84 |
120 |
61 |
|
50 |
79 |
150 |
58 |
It is convenient, in calculations of the amount of water evapo- rated at various i)ressures and from various temperatures of feed, to reduce ihcm to a common standard, namely, the ecjuivaliait amounts that would be chaiigtid into steam of atmospht^ric ])re8- Bure, if the temperature of feed was 212 Fahrenlieit ; or, as it is commonly called, to evaporation " from and at 212°." Two tables are ap])ended, for the i)urpo8(! of facilitating this reduction. The second table is taken from Professor Rankiue'a " Treatise on the Steam J'higine."
Pressure and Temperature of Steam.
|
I'rcKKurc by gauge. 0 10 20 |
Ten |
peiiilure ircniicil. ..212" ..239" 250" |
Pressure by gauge. 60 70 80 90 |
T. |
Miperature ilneuheit. . .307° -.316" .324' |
|
30 |
.274". .287' .298" |
. 331" |
|||
|
40 |
100 |
. 338' |
|||
|
50 |
110 |
. .344 |
EXGINEEKING.
65
Pressure
by gauge.
120... 130. . . 140. . . 150. . . 160. . .
Temperature Fahrcuheit.
.350° .356° 361° .366° .370°
Pressure
by gauge.
170. . . 180. . . 190. . . 200. . .
Temperature Fahrenheit.
..375° ..379° ..384° ..388°
Factors of Evaporation.
Tempe- rature of the steam.
212°....
230°
248°
266°
284°. ... 302°....
320°
338°
356°
374°
392°
410°. . . .
Temperature of the feed-water.
1.19 1.20 1.20 1.21 1.21 1.22 1.22 1.23 1.2;3 1.24 1.24 1.251
1.17 1.18 1.18 1.19 1.20 1.20 1.21 1.21 1.22 1.22 1.23 1.23,
1.16 1.17 1.18 1.18 1.19 1.19 1.20 l.£0 1.21 1.22
1.13 1.14 1.14 1.15 1.16 1.16 1,17 1.17 1.18 1.18 1.19; 1.20
|
104° |
122° |
140° |
158° |
176° |
|
1.11 |
1.10 |
1.08 |
1.06 |
1.04 |
|
1.12 |
1.10 |
1.08 |
1.06 |
1.04 ' |
|
1.13 |
1.11 |
1.09 |
1.07 |
1.05 . |
|
1.13 |
1.11 |
1.09 |
1.07 |
1.00 i |
|
1.14 |
1.12 |
1.10 |
1.08 |
1.06 |
|
1.14 |
1.12 |
1.11 |
1.09 |
1.07 |
|
1.15 |
1.13 |
1.11 |
1.09 |
1.07 |
|
1.15 |
1.14 |
1.12 |
1.10 |
1.08 |
|
1.16 |
1.14 |
1.12 |
1.10 |
1.08 |
|
1.17 |
1.15 |
• 1.13 |
1.11 |
1.09 |
|
1.17 |
1.15 |
1.13 |
1.11 |
1.09 |
|
1.18 |
1.16 |
l.:4 |
1.12 |
1.10 I |
194° 212°
1.02 1.02 1.03 T.04 1.04 1.05 1.05 1.06 1.06 1.07 1.07 1.08
1.00 1.01 1.01 1.02 1.02 1.03 1.03 1.04 1.04 1.05 1.06 1.06
To illustrate tlie use of the tables, suppose an engine of G liorse-power is supplied with steam at a .pressure of 50 pounds ]ier square inch, and that the temperature of the feed-water sup- plied to the boiler is 160". It is required to find how much water must be evaporated per hour" from and at 212 " for the engine. The temperature of steam having a pressure of 50 pounds is 298°. In the table of " Factors of Evaporation," the factor correspond- in<r to a steam temperature of 302° and a feed temjierature of 158° (which are the numbers in the table nearest to the given ones), is 1.09. Now this engine requires an evaporation of 6 times 79, or 474 pounds of water per hour, at a pressure of 50 pounds, or an equivalent evaporation " from and at 212"" of 1.09 times 474, which is equal to 516.66 pounds.
IV. — To find the proportions suitable for a boiler whicJi is to have a ffive/i evaporation, (a) To ascertain the grate-surface in square feet : Divide the number of pounds of water to be evaporated per hour, from and at 212% by 75, for cylinder boilers ; by 77, for flue boilers ; by 78, for tubular boilers ; by 80, for locomotive and ver- tical boilers.
Example. — Suppose that a cylinder boiler is to be proportioned for an evaporation of 500 lbs. of water per hour, at a pressure of 75 lbs., the temperature of the feed-water being 80°. The equiva- lent evaporation will be 1.17 times 500, or 585 lbs., and the grate- surface 585 divided by 75, or 7-ro- square feet.
(b) To ascertain the heating surface in square feet : Multiply the grate-surface by 11, for cylinder boilers ; by 17, for flue boilers ; by 30, for tubular, locomotive, and vertical boilers, (c) To ascer- tain the cross-section of flues or tubes in square feet : Multiply the grate-surface by 0.134. This is an average value for good practice, &nd it can be varied between the limits of 0.135 and 0.143, as may
66 ENGINEERING.
be most convenient. ((?) To ascertain the length of hoiler : Cylin- der boilers should be from 10 to 13 times the diameter ; flue boilers from 5 to 6 times the diameter ; tubular boilers, and the shells of locomotive and vertical boilers, from 3 to 3i times the diameter. There is very great variation from these figures in practice ; but the numbers given al)ove represent the most gene- ral limits, so far as they can conveniently be classified.
Example- — What are the dimensions of a tubular boiler for an engine that is to develop 4^ horse-power, with a steam-pressure of 100 lbs., the temperature of the feed-water being 1G0° ?
The equivalent evaporation required per liorse-])ower per hour is 1.1 times 63, or OO-^'u lbs. The total equivalent evaporation is 44 times GOi^o, or about 312 lbs. Hence the grate-surface, being the quotient arising from dividing 313 by 78, is 4 square feet. The heating surface is 30 times 4, or 130 square feet. The cross- section of the tubes should be about 0.53G square feet (4 times 0.134), or it should vary between the limits of 0.5 (4 times 0.125) and 0.573 (4 times 0.143) square feet.
While the rules relating to engines given above are generally only applicable for cases within the limits mentioned at thiB be- ginning of this article, those for the proportions of boilers give safe average values for the majority of axses that are met with in practice. B.
Engines, Derangements of. — These are hot bearings, loose keys, and leaky joints. If a bearing heats continually, when properly adjusted and well lubricated, it is too small. Some- times l)earings heat on account of dirt or grit, becausti they are set up too tightly, or are out of line. A hot bearing can often be cooled without stopping the engine, by mixing sulphur or l)lack- lead with the oil, or by turning on a stream of water from a hose. If a joint blows out it can sometimes be wedged, so tliat the engine can be run until stoj)inng tinu;. An engineer should exercise all liis ingenuity to overcome a (lifRcuI ty without slo])- ping the engine, except in cases where it would Ix^ dangerous to continue to run. If keys or bolts become loose, it will generally be indicated l)y a thump in the engine. To prevent the freezing of pipes and connections in exposed situations, they should either be thoroughly drained, or the water should be kept circulating in them. B.
Exhaust Steam. — This should not be discharged into a brick chimney. It is liable to disintegrate the mortar and destroy the chimney.
Steam-EngineGoveknous. — The ordinary ]iendulum governor consists of a vertif-al s))indl<', which is made to revolve by suitable mechanism, and carries, on opposite sides, a pair of arms, to wliii-li licavy weights are attached, forming revolvingpendulunis, whicli vary their ])08itions at dilTerent si)eeds. 'I'he Himj)U'St form of construction is shown in Fig. 1, A B l)eing the revolv- ing spindle, V, and I) tlm weiglits, secured to the spindle l)y rods jointid at (J. Sev<Tal positions of tbe liiills are shown, corn;- sjionding ti) (lilTcirnt spi'eds of rotalion. In any of these jiosi- tions, the verlii ill distanci-, as (J l'\ I'f tlie point of suspension, (i, above tlie centres of tlie i)alls, is called iln- A.////// of the(joveTiioi\
ENGINKKIUjSTG.
67
and it can be found for any case by dividing 33,508 by the square of the number of revolutions per minute. For instance, if a governor naalics 100 revolutions per minute, running with- out friction or other resistance, the vertical distance of the cen- tres of the balls below the point of suspension would be 32,508 divided by 10,000 (the square of 100), or about 3i inches. A table i? added, showing- the heights corresponding to various speeds.
Table.
Revolutions Height in
per minute. inches.
10 352.08
20 88.02
30 39.12
40 22.01
50 14.08
60 9.78
TO 7.184
80 5.501
90 4.347
100 3.521
125 3.253
150 1..564
175 1.150
200 0.8802
225 0.6955
250 0.5G33
Revolutions Height in
per minute. inches.
275 0.4646
300 0.3912
350 0.2873
400 0.2201
450 0.1739
500 0.1408
550 0.1164
600 0.0978
650 0.08333
700 0.07184
750 0.06259
800 0.05501
850 0.04873
900 0.04347
950 0.0:)901
1000 0.03521
68
ENGINEKKIKG.
In practice, the pendulum governor is generally constructed somewhat as represented in Fig. 2, being connected to the con- trolling mechanism by f<hort lever.s, so that a slight change in the position of tlie balls will move the regulator considerably. In estimating the height of the balls of such a governor, it is to be measured from E, where the centre lines of the arms produced cut the centre of the spindle.
When a governor, acts on the controlling mechanism of an en- gine, it encounters some resistance. There is also some friction of the moving parts, and a weight is sometimes added, either sliding on the spindle or connected to the spindk- by a lever, in order to make tlie governor more sensitive. All these things in tiueuce the height of the governor. In a well-made instrument the friction is insignificant, and need not be regarded, but allow- ances must be made lor the resistance, and the weight, if any is attached. Find how numy pounds of force are re(juired to move the controlling meclianism of the engine, and lind the weight
of the balls and <i( the attached weight, in i)ounds. Next de- termine how far the controlling ineclianism is movt^l, and th(^ attaclu^d weight raised or lowered, for a given change in the height of tlu! governor l)alls. Divide tint (iistanc(! moved l>y the resistance l)y tlu; change in height of the bails in the same time, and multiply the <]Uotient by tlu^ measure of the resistance in ])()unds : dividi' also the vertical distance moved by the attached weight for a iriveii change in the height of tlie balls, and multi- ply tlie (piotient liy this weight. Take tlie sum of these two jiro- ducts and the weight of tlu! governor-balls, and divide liy the weight of tlui governor-l)allH ; multiply t\w (juotiiMit by the lieight ff)r a governor working freely, takc^n from the tabh; above : the (jiiotient is the correctrd lieiij-ht of th(^ governor-balls.
h\ri//ii />/<■.■ — Tli(i two l);illsof a governor weigh 20 lbs.; the rcisi.s- tance of the iiicchaiiisni is 10 lbs., and it moves l in. wliile the heiifht of the balls chungeH } inch. The attached weight is M lbs., and it moves 2 inches vertically, while tiie lii-ight of the balls ♦•lianges ^ in. What is the heiglit of Imlls for a speed of !200 revolutions a mimiteV Multijilyini!: the (piotient of 1 divided by ,| (4) l»y 10, tlie product is 10 ; multiplying the <piotient of 2 divi<l-
ilNGINKKRlNG. 69
ed bj i (8) 1)V 8, tlie product is 64 ; dividing the sum of 40, 64, and 20 (124) by 20, the quotient is 6.2 ; multiplying 6.2 by 0.8802 (the height for a free governor making 200 revolutions a minute), the product, the corrected height of the governor-balls, is about 5^ inches.
In designing a governor, it is well to fix upon some range of speeds between which it shall control the engine, and make the balls heavy enough to effect this. The proper weight for the balls can be found approximately, as below:
(1) Divide the distance through which the resistance moves by the change in height of the governor-balls in the same time, and multiply the quotient by the resistance ; divide the vertical dis- tance through which the attached weight moves by the vertical distance moved by the balls in the same time, and miiltiply the quotient by this attached weight ; add together these two pro- ducts, and divide the sum by 2.
(2) Subtract the mean speed of the governor from the greatest speed it is to have, and divide the difference by the mean speed ; divide the quantity obtained in (1) by this quotient : the result will be the weight of the two balls.
Example. — Suppose the resistance and attached weight are the same as in the preceding example, and that the speed of the governor is to vary between 200 and 300 revolutions a minute, in controlling the speed of the engine. What should be the weight of the balls?
(1) The sum of 40 and 64 (the corrected resistance and attached weight) is 104 ; 4- of 104 is 52.
(2) The difference between 300 and 200 (100), divided by 200, is 0.5 ; the quotient of 52 divided by 0.5, or the weight of the balls, is 104 lbs., so that each ball must weigh 52 lbs. B.
Horse-power, Different kinds of. — In making an estimate or measure of the effect of any piece of mechanism that is used to overcome resistance, it is necessary to have a unit of reference. In whatever manner the resistance is overcome, if it can be mea- sured it can be converted into the amount of work that must be expended to raise a weight through a distance, since by suitable arrangements the mechanism can be put in motion and made to overcome resistance by allowing the weight to fall. This gives a simple mode of estimating the work, by assuming that a unit of \«ork is the amount required to raise 1 pound a distance of 1 foot vertically. To illustrate, suppose that a cut is being taken from a 6-in. shaft in a lathe, and that the resistance to the motion of the cutting-tool is 200 lbs.; how many units of work are performed each time the shaft makes a revolution ?
In each revolution of the shaft, the tool makes a cut 6 times 3.1416, or 18.8496 ins., or 1.5708 ft. in length, and the work is the same as would be required to raise a weight of 200 lbs. through ;i vertical distance of 1.5708 ft., or it is 314.16 units.
Now, if :!3,000 units of work are performed in a minute, they constitute a unit of power, known as a horse-power' — and con- versely, a horsepower can be defined as the power required to raise 33,000 lV)s. 1 ft. high, or do 33,000 units of work in a minute. Again, a horse-power may be defined as the power re- quired to perform 550 units of work in a second, or 1,980,000
70 EXGIXEERING.
units in an hour. To apply the principle to the example given above, suppose the shaft makes 20 revolutions a minute, how many horse-power are required to drive the t(jol ? In this case, the units of work performed per minute would be 20 times 314.16, or 6383.2, and the horse-power would be ^htWd of 6283.2, or about ju'g of a horse-power. It will be seen, from this e ample, that if the resistance to motion in pounds and the speed of motion in feet per minute can be measured, it is only necessary to multi- ply them together, and divide by 33,000, in order to obtain the horse-power. The steam-engine is a uiachine that is commonly rated as being of a certain horse-power, but the term horsepower, as thus used, does not always have the same meaning. In fact, there are four kinds of horse-power by which an engine may be rated :
1. Gross or indicated horse-power.
2. N'et or effectim "
3. Total
4. Nominal
1. Tiie gross or indicated horse-power of an engine is the power calculated by assuming tiie resistance to be that due to the mean effective pressure of the steam on the piston, as shown by the in- dicator. Thus, suppose this pressure is 3500 lbs., and the piston moves 400 ft. a minute, the gross horse-power is 400 times 3500 divided by 33,000, or 30.3.
2. The net or effective horse-power of an engine is computed from the useful resistance overcome. If, in the preceding exam- ple, the pressure on the piston, after deducting that required to overcome the friction of the engine, is 2200 lbs., the effective horse-power is 3300 times 400, divided by 33,000, or 36.7.
The net horse-power is the proper kind to be specified by a steam-user when he is buying an engine.
3. The total horse-power of an engine is computed from the to- tal pressure on the piston above a vacuum. If, in the example given in Case 1, the total pressure on the piston is 4200 lbs., the total horse-power is 400 times 4200, divided by 33,000, or 50.9.
Total horse-power is only used in comparisons of the results of experiments.
4. The nominal horse-power of an engine has no mi'uning in particular — that is to say, there are a number of different rules by which it may be computed. Tiius, there is tlie admiralty ruli^ for nuirine engines, Mr. Bourne's rule for condensing engines, -Mr. Bourne's rule for non-condensing engines, James Watt's ruli^ ; and numi'xous engine-builders have private rules of tlieir own. For instance, ^1 says, " I will make an engine with a cylinder 10 ins. in diameter, and a stroke of 15 ins., and I will call it 8 liorse-power, nomiiuil."
li, who l)uil(ls an engine of the same size, and wants to nuike purcluisrrs tiiiidv tlicy are getting more for their money, says, " I will call my engine l(i liorse-])ower, nominal." The man who jfoes to buy a steam-engino of either of these j)arties may very properly say to tliem, " How much will you charge me for an engini- guaranteed to be of so nuiiiy horse iK)Wi'r, aitual ?" B.
Im)KAT(»1{, The steam-engine. — The construction is shown in Figs. 1 and 2, Fig. 1 being an elevation, and Fig. 3 a section.
1
ENGINEERING.
71
The iudicator is a recording steam-gauge, very accurately made, for determining the pressure acting on the piston of an engine, at every point of the stroke. It is connected to the cylinder, close to one end, and wlien the cock, seen in Fig. 1, is opened, the steam presses on a small piston, shown in Fig. 2. A stifE spiral spring above this piston is compressed by the pressure of the steam. The piston-rod, it will be seen, is connected to a lever, and this, in turn, with a: link and another lever, a pencil or marking-point being placed in a hole in the link. There is a cylindrical barrel to the left on which a piece of paper can be placed, being held by two clip springs. This barrel can be made to revolve by pulling a string wound round the bottom, and it has within it a coiled spring, which makes it turn back again
Fig. 1.
the indicator.
Fig. 2.
when the tension of the string is relaxed. Now, suppose that the indicator is attached to the cylinder of an engine, and the cord is fastened to some moving part, so that when the engine makes a stroke it causes the barrel carrying the paper to revolve, and on the return stroke the coiled spring in this paper barrel makes it turn back to its original position. Meanwhile the steam in the cylinder is pressing on the piston of the indicator, forcing it up a distance corresponding to the pressure, so that if the pencil is allowed to touch the paper, it will trace out a line which repre- sents the pressure, and this line is called an indicator diagram. Such a diagram is shown in Fig. 7. The atmospheric line, C D,
V2
ENGINEERING.
is traced when the cock is closed and there is no pressure on the piston. At b, the stroke of the engine commences, and when the piston has gone about half way to the other end of the cylinder, the steam is cut off, as shown at c, and the pressure begins to fall as the steam expands. Near the end of the stroke, the exhaust- valve opens, as shown at d, and the pressure falls more rapidly. When the engine makes the return stroke, there is only the back pressure^ until near the end, when the exhaust-valve closes, shown at /, and the steam being compressed, the pressure rises. Just before the end of the stroke, at a, on the diagram, steam is admitted, and the pressure rises suddenly.
I. How to attach the indicator to the ryliader of an engine. . Drill a hole in the cylinder, in the head, or close to the end,
and tap it out for a half-inch iron nipple. The indicator-cock must be connected to this, using an elbow, if necessary, and then the indicator can be attached at pleasure. In drilling this hole, do not make it close to the ports. Sometimes the connections from the two ends of a cylinder are brought together, and one indicator is made to answer for both ends, a cock being fitted in each pipe, so that either can be opened to the indicator, as desired. In such a case, the holes in the cylinder should be larger, for three-quarter inch pipe, at least, so as to prevent any loss of pres- sure. It is obvious, however, that as the indicator is used to ob- tain the pressure in a cylinder, the more closely and directly it is connected, the better.
II. IIoic to make the paper barrel have a motion coincident with that of the pidon.
a. Rednciny-iclieel. — Fig. 3.
J^e:^.J
This is attached to some part of tlie ongino-rramo, and the cord marked " to euirino" is mnde fast to tlw crnsshead, being carried over a pulley, if necessary, so tluit it is parallel to the guides, 'i'he other cord is fastened to the cord wound round tlie paper barrel of the indicator. Tlie two whci-ls bi-ar the siinic j)ro]iortion to each r)tlif'r as the stroke of Ihr enginr does to thr (iesired range of motion for tlie paper barrel, tlie latter being usually from 4 to
ENGINEERING.
73
5 iuches. There is a coiled spring in the reducing-wheel, which makes it turn back on the return movement of tlie cross-head. By having different sized wheels to carry the cord leading to the indicator, this arrangement can be adapted to engines with dif- ferent strokes. b. Swinging -board, with slot. — Fig. 4.
Mark a point, A, at some convenient distance from the cross- head, and on a line perpendicular to the guides, at the centre of the stroke. Attach a board so that it can swing freely around this point ; cut a slot in the other end, for a pin connected to the cross-head. Then, as the cross-head moves, it will make the board swing to and fro. At some point B, of the board , which
has the proper movement for the paper cylinder, attach a cord or wire, and carry it over a pulley, C, adjusted at such a height that the part of the cord, B C, is parallel to the guides when the en- gine is at half stroke. The cord can then be brought down and attached to the cord of the paper barrel.
74 ENGINEERING.
c. Smnging-boqrd, tcith link. — Fig. 5.
Sometimes it is uot practicable to attach the board directly to the cross-head by a piu, aud it is more coiiveuient to use a liuk connection, the arrangement of which will be evident from the figure.
It is easy to see that a number of arrangements could be de- vised on the general principle of the swinging-board. Sometimes it is attached to the guides by a standard, and sometimes one end is connected to the cross-head and the other to the indicator, the point aroaud which the board swings being between, at distances from the two ends proportional to the stroke of the engine and the movement of the paper barrel. Whatever the special arrange- ment, attention should be given to these two points :
\st. To have the hoard perpendicular to the guides wJien tlie en- gine is at half stroke.
2d. To lead tlie cord off in a direction parallel to the guides.
III. How to take an indicator diagram.
If a cord is used for the motion, it should have a slide on it, so that it can be adjusted, and it should have a hook so that it can be attached to the cord of the paper barrel, and detached at pleasure. Fine wire is better than cord, as it is quite flexible, and does not stretch so readily. If several cards, taken at inter- vals, are of the same length, the connection is all right. Having got the motion properly adjusted, turn the cock of the indicator so that it will blow through, having first put a piece of paper on the paper barrel. Then turn the cock so as to let steam into the indicator, and press the pencil lightly against the paper ; draw it back as soon as the card is traced, shut the indicalor-cock, and apply the pencil again, to trace the atmospheric line — be par- ticular not to trace the atmospheric line until the diagram is taken ; then unhook the cord, remove the diagram from the paper cyliniU'r, and mark on it the pressure of steam by gauge, the revolutions per minute, the height of the barometer, and the temperature of the engine-room — if the proper instruments are available — and the vacuum by gauge, the temjierature of the liot-weli, and the temperature of the injection-water, if the dia- gram has Ix'cn taken from a condensingcngine. All the dimen- sions of the engine should also i)e noted, for future reference, to- gether with such particulars in regard to the dimensions and per- formance of th(! boiler as can be obtained.
A counter should alwavs be enii)loyed to detennine the number of revolutions ])er minute, at tlie time the diagram is taken. It can be connected to the indicator motion, or to souu^ moving part of the engine. Take its reading at the beginning of a minute, and at the end, having indicated the engine meanwhile. This gives the revolutions at tlie time the card was taken, with consid- erable accuracy.
IV. Ifinr to draw the true dittr/ram. — Fig. 0.
Tlie indicator diagram from oik; end of tlu; cylinder, it is evi- dent, only shows wlutt takes ])lace on the side <if the ])iston on wliich till- indicator is applied— but at the same time tliere is some hiuk pressure on the other side, opposing the motion of tlie
ENGliSrEERING.
V5
piston. To get the actual diagram, therefore, it is necessary to take diagrams from both ends of the cylinder simultaneously, and then combine the parts of each that were traced at the same time. Thus such a figure as is shown in Fig. 6 is obtained. On one side of the piston, the line a b c f is traced, and d c eis traced at
a
^£^.^'
the same time on the other, and the figure so obtained is the trite diagram representing the distribution of the pressure. In using the diagram as ordinarily taken, therefore, the actual effective pressure is not obtained ; but there is no error in practice, since the inaccuracies of the diagrams from the two sides balance each other. It is a great mistake, however, to take diagrams from one end of a cylinder only, and assume that those from the other would be similar. Quite often there are serious differences, and both ends of a cylinder should always be indicated, if possible
V. Ho\o to ascertain the mean effective pressure from a diagram. —Fig. 7.
a. 1st method.— T>v&vf perpendiculars to the atmospheric line, from the extremities of the diagram, thus determining its length, C D ; divide the line, (J D, into 10 equal parts, and midway between each of the divisions erect a perpendicular to C D, drawing it between the upper and lower boundaries of the diagram ; measure the length of each of these lines on the scale of the indicator-spring, add the measurements together, and divide the sum by 10. In the figure, the pressure, or length
76
ENGINEERING.
of the line on the scale, is shown at each perpendicular. The sum of these is 363, so that the mean effective pressure is 36.3 lbs. per square inch.
b. 2d method. — Draw perpendiculars between the ten divisions of G D, as explained above. Then take a strip of paper, apply it to the first perpendicular, and mark the length ; apply it to the next perpendicular, and mark its length, next to the first ; so continue applying it to each, and when the last perpendicular has been measured, the distance between the first and last marks will be the sum of all the lengths. The strip of paper. A D, is shown in the figure as applied to the third perpendicular. Measure the length of the paper between the extreme marks, in inches, multi- ply it by the scale of the indicator-spring, and divide by 10. Sup- pose, in the present case, that the length of the paper is found to be 13.1 inches, and that each inch represents 30 lbs. on the scale of the indicator-spring ; 30 times 13.1 is 363, so that the mean effective pressure is 36.3 lbs. per square inch, as before.
c. Positive ami ntyatice pressure. — Fig. 8.
When the steam is cut off very early in the stroke, and the valves and piston are tight, a diagram is sometimes drawn like that in the figure, iu which the back pressure is greater than the forward j)ressure for a ])ortion of llu' stroke, and the pressure determined from the ])f)rtion of the diagram a r b must be sub- tracted from tli(! jiressure due to the portion d e n f. In such a case, the method of determining the mean pressure is as follows : Divide tlie atmosjiheric line into 10 equal parts, as before, and draw i)erpendiculars midway between them ; add togetlier the j)erpendiculars (mea.surc'd in the scale of the indicator-sjtring) in th(i positive |)art of the diagram, also those in the negative jiart ; subtract tln^ latter from the first sum, and divide tin- difft^rence by 10. In the. figure, Ww, pressures at the different ))er|)endiculars are jriven. The sum of tln^ i)ositiv<' jjre.^siires is 179, of the nei^ative pressures 35, and the difference is l.')4 ; ho that tlie mean effective pressure is 15.4 lbs. jxt wpiare inch.
W. If "in to find the indicated horse-poiner of a steam-engine.
Having dctciniinrd tlic mean effective pressure from » diiigram, l)y one of tlie methods explaiiK-d abovi;, multiply this pressurt; by tlie product of the stroke in feet, the square of the diameter of
ENGINEEKING.
77
the cylinder in inches, the number of revolutions per minute, and 0.0000476.
Example. — Suppose the mean effective pressure is 50 lbs. per square inch, the diameter of the cylinder 15 inches, the length of stroke 2 feet, and the number of revolutions per minute 80. Then the horse-power is the product of 50,225 (the square of 15), 80, and 0.0000476, or 85.68.
VII. How to construct the theoretical diagram. — Fig. 9.
J^f'^. ^.
This is the diagram that would be taken if the steam acted in the cylinder with the pressure at the beginning of the stroke un- til the point of cut-off, and that then the admission ceased instan- taneously, and the steam expanded, in accordance with Mariotte's law, to the end of the stroke, when the exhaust-valve opened, and the steam was immediately condensed, creating a perfect vacuum in the cylinder for the return stroke. Such a diagram is repre- sented hj A B C D E, this being the theoretical diagram for the actual diagram, a b c d e. The following is the method of laying it down: Draw a line, E D, a.t a distance below the atmospheric line, n d, equal to the pressure of the atmosphere (14.7 lbs. per square inch on an average), on the scale of the diagram ; mark on E D the length, o D, of tlie actual diagram ; then find the to- tal volume of the clearance spaces at the end of the cylinder from which the diagram was taken, and make o E bear the same rela- tion to 0 D as this volume of clearance has to the total volume swept through by the piston per stroke. To make this plaiii, sup- pose that in a cylinder having a diameter of 24 inches and a stroke of 3 feet, it is found that the volume of the clearance spaces at one end of the cylinder is 900 cubic inches. The volume swept through by the piston per stroke is the product of 0.7854, 24 squared, and 36 or 17,286 cubic inches, so that the clearance is about y^-g-jy of tlie piston displacement, and o E must be made toot as long as o D. Thus, if 0 D is 5 inches, o E must be -,"o% oi an inch. Having de- termined the point E, make E A perpendicular to ED, and draw a line, A B, parallel to ED, at such a height that it represents the initial pressure of the steam. Through c, on the actual dia-
78 ENGINEERING.
gram, where tlie steam is cut off, draw a perpendicular, B H, to ED. Divide ED into any number of equal parts, and erect per- pendiculars at the points of division that are l)eyond the point of cut-ofF. From E draw any diagonal line, E F, and from E as a centre, with a radius E II, draw an arc cutting E F in the point G. From the same centre, and with radii equal to E A, E 5, etc., draw arcs cutting E F. The arc drawn with a radius E 4, cuts E Fin the point /. Draw the line f A, and from G draw a line, G ff, parallel to /A. From g draw a line, </ /i, parallel to f A, and the point 7i, in which it cuts the perpendicular drawn through 4, is a point of the curve of expansion. The construction of the points on the other perpendiculars is i:)recisely similar, and is in- dicated in the figure. Having determined a sufficient number of points, draw through them the curve of expansion, B h i k I in C, and the theoretical diagram will be completed.
This kind of diagram is useful for comparing the merits of dif- fei'ent engines, since it is evident that, other things being ecjual, the engine whose actual diagram most closely approaches the theoretical is the best. The mean i)ressure, as shown by such a diagram, can be determined by one of the methods already ex- plained, for ctmiparison with the pressure given by the actual diagram.
VIII. IIotD to take care of the indicator. — Al ways oil the cylinder and all moving parts before api)]ying the instrument to an engine. Never use any thing l)ut the finest grade of oil, such as that specially ])repare(l for sewing-macliines or clocks. After taking oiu! or two diagrams, remove the intlicator, and examine its steam- cylinder. If any grit has entered, wijje it out, using soft cotton- waste on the end of a white-pine slick. It is important to attend to this on indicating an engine of which the condition is not known, and if it is found tluit dirt or grit is forced into the indicator, it should b(^ cleaned at frcciuent intervals during the experiments. As soon as tlie experiments have been concluded, remove tlu^ indi- cator, and when it has cooled sufficiently, wipe it out and ai)i)ly oil in the steam cylinder, and to all the moving parts. Be careful to dry till! si)ring thoroughly, and cover it with f)il. Never put any liard sui)stance into tlu; steam-cyrnidcr. but use a whit('-i)ine Stick and soft cotton-waste. After u.se, take out tin* ])lug of the indicator-cock, clean it and the seat, ajjjjly oil, and on rei)lacing it adjust it so that it moves f redely and does not leak.
It might be supposed that minute directions of this kind were suiHTfhious, and tliat any one owning an indicator would see tlie necessity of using su(;h a delicate instrument with great care. The generality of the indicators in common use, however, ini- presB the observer with the idea that all the directions recittnl al)ove liavf- been studiously neglected B.
Sr,Ti)K-VAT,VK8, Setting. — The methods of adjusting the lap ;ind travel of slidcsvalves, and tlw jiositioii of the ecci-ntric, given itel(»w, are taken, with some slight modifications, from the work of Dr. Zenner, on Siide-Valve (Jeuring. It is IxOieved that the sinijilicity of the construction will be appreciated by th(! reader.
ENGINEERING.
79
I. Area of ports. — To find ilie proper area of port for a,n en- gine of a given piston-speed, multiply tlie area of the piston,
-fc^
SETTINS THE SLIDE-VALVE,
in square inches, by the number nearest to the given piston-speed in the table on the next page.
80 ENGINKEIUNG.
Speed of piston, in feet, Number by which area of piston
per minute. is to be multiplied.
lUO 0.02
200 0.04
300 0.06
400 0.07
500 0.09
600 0.1
700 0.12
800 0.14
900 0.15
1000 0.17
1100 0.19
1200 0.2
1300 0.22
1400 0.24
1500 0.25
II. Lap, lead, and travel of valve. — The amount of opening given by the valve for the admission of steam or its exhaust, at the commencement or termination, respectively, of the stroke of an engine, is called the lead, either steam or exhaust, as the case may be. If tlie face of tlie valve is wider than the port, the ex- cess of width is called lap, and may be either steam or exhaust lap. Steiim-lap is an excess of widtli on the outer extremities of the valve-faces, and exhaust-lap an excess on the inner fac,es. The effect of steam lap is to cut off the steam at an earlier point of the stroke, and exhaust-lap causes the exhaust to open later and close earlier than it otherwise would. It must be obvious that the action of the exhaust would be very much deranged if an attempt was made to cut off very short, and it is found, in practice, that tin; limiting ])oint of cut-off with the simple slide- valve is at about two thirds of the stroke.
The travel of the valve is the distance between its two extreme positions. For a valve without lap or lead, the travel is equal to twice the width of the? steam-])ort. If lap is added, tlie travel of tlie valve is equal to twice the width of the port, increased by twice th(! amount of steam-lap on one end.
III. The crcriilnc. — The eccentric, which moves the valve, is a substitute for the crank, and consists of a circular disk secun^d to the shaft, the centre of the disk lying outside of the centre of the sliaft. The diKtance between the centres of the eccentric and the shaft is e(jual to half the travel of the valve. If a valve has neither lap nor l<;jid, tlu^ eccentric is secured to the shaft in such a position that a line joining its centn^ with the centrtM)f a shaft is perpendicular to a line connecting the centre of the shaft and the, c(!ntre of the craid^-])in. If the valves has h^ad, the eccentric must b<! turned on the shaft suflicieiitly to secun; the desired iiiiiount, and if lap is also added to the steam side, the eccentric must b(^ advanced still further. In either of these cases, the amount the (iccentric is moved forward is termed the angular ad- vances of the (jccentric, l)eing the angle niadc; by a line joining the centres of the eccentric and shaft with a lint! drawn tiirough the centre of the sliafi perpeniiiciihir to the line of centres of the
ENGINEERING. 81
crank-pin and shaft. The points in which these two perpendicu- lar lines intersect the shaft should be plainly marked by a centre-punch or chisel, for convenience in adjusting the eccentric.
IV. Proportions of valve and .teat. — The bridge of the valve- seat sliould generally have a width equal to the thickness of the cylinder. The width of the exhaust-port is found by adding the width of the steam-port to the half-travel of the valve, and sub- tracting the width of the bridge.
The length of the valve is equal to the width of the exhaust- port, increased by the width of the bridges and the two faces.
V. To find the lap and travel of the valve, and angular ad- vance of the eccentric, for given points of admission, cut-off, and release. — Draw a horizontal line, A B, and lay off on it, any dis- tance, A C, to represent the length of stroke of the engine. Make E S equal to the length of the conuecting-rod between centres, and S D equal to one half of A C. With 2) as a centre, and D 8 as a radius, describe a circle, which represents the path described by the centre of the crank-pin. The arrow shows the assumed direction of the motion of the engine. Assume some point, E, at which it is desired to have the steam-valve beyin to open when the piston has still to complete the portion E A oi its return stroke. Assume also a point, F, at which the steam is to be cut off when the piston has advanced a distance, E F, and a point, Q, at which the exhaust-valve is to be begin to open when the pis- ton has completed the portion E O oi the stroke. Then, with each of these points, E, F, G, as a centre, and with the length of connecting-rod, ^ «S, as a radius, describe an arc of a circle cut- ting the path of the crank-pin in the three points e, f, g. Join each of these points with the point D, thus determining the po- sition, D e, of the crank at the instant of admission, its position, D f, at the instant of cut-off, and its position, D g, at the instant of release. Bisect the angle e D fbj a straight line, D L ; make D Lot any convenient length, and upon it, as a diameter, describe a circle, and note the point, M, in which it cuts D e. From D as a centre, and with D 31 us a radius, describe an arc of a circle, MB N. Measure the lengths of the lines B 31 and B L, and divide the former by the latter. Subtract the quotient from 1, and di\'ide the width of steam-port by the difference. This gives the travel of the valve. Multiply the travel of the valve by half the quotient obtained above, and the product will be the steam-lap. The angle L B I is the angular advance of the eccentric. Di- vide the length of S R by the length of L B, and multiply half the quotient by the travel of the valve : the product is the steam- lead.
Next produce the line L B, making B 0 equal to B L, and upon Z) 0, as a diameter, describe a circle, noting the point, P, in which it cuts B g, the position of the crank at the instant of re- lease. Divide the length of Z) P by the length of B 0, and multiply half the quotient by the travel of the valve, which gives the exhaust-lap. With Z) as a centre, and i> P as a radius, de- scribe an arc, P T Q, noting the points, T and Q, in which it cuts A B, and the circle whose diameter is B 0. Divide the length of T Why the length of B 0. and multiply half the quotient by the travel of the valve : the product is the exhaust-lead. Through the
82 ENGINEERIlSrG.
point Q draw the line Z) // : tliis is the position of the crank at the instant the exliaust-valve closes and cushion commences. With h as a centre, and A S, the length of the connecting-rod, as a radius, describe an arc cutting the line A B in the point H ; tlieu G II is the portion of the return stroke completed when the exhaust-valve closes.
On account of the angularity of the connecting-rod, the points of cut-off and exhaust closure will vary somewhat on the re- turn stroke. They can be equalized by a slight change in the an- gular advance and length of the eccentric rod.
VI. Exiimple. — The following example will serve to illustrate the application of the preceding principles :
A valve is to be designed for an engine having a cylinder 20 inches in diameter, and a stroke of 2i feet, making 80 revolutions a minute. The length of the connecting-rod is 6^ feet. The valve is to admit steam when the piston has made 0.997 of the stroke, is to close the steam-port at two thirds of the stroke, and open the exhaust when /'(fn of the stroke has been completed.
The area of the i)iston, in s<iuare inches, is 0.7854 times 400 (the square of 20), or 314.16, and the piston-speed is 400 feet per minute ; hence the proper port area is 0.07 times 314.16, or about 22 square inches. Assuming the length of the port to be ecjual to the dianieter of the cylinder, 20 inches, its width will be ./,, of 22, or 1.1 inches. The width of the bridge must be equal to the thick- ness of the cylinder, or \\ inclies. In tlie figure, make J57iS' equal to 2i times A 'C, and E A, 0.997 of A G, A F,io{ A G, and A G, 0.95 of A G. Constructing the positions of the crank corre- sponding to these jioiiits of stroke, and making tli(^ other con- structions as explained above, suppose that the data obtained from the figure l)v measurement are as follows :
Angle li D M, 5^ ; angle M D jST, 108|' ; angle R U P, 151^° ; angle T D Q, 137|-^ ; angle L D I, an(pilar advance of ecrcntric, 40^^° ; 7) M, 0.65 of an inch ; I) L and D 0, each 1.5 inches; D P, 0.19 of an inch ; SB, 0.1 of an inch ; T W, 0.375 of an inch ; (' II, part of return stroke eomplet<d when exhaust closes, O.S~). Dividing D M (0.65) by D L (1.5), the quotient is 0.43+ ; sub- tracting 0.43 from 1, the remainder is 0.57 ; dividing twice the width of steam-])ort, 2.2, by 0.57, the quotient, the travel of the vali)e, is 3.80 inches. Multiplying * of 0.43 bv 3.80, the product, the steam-lap, is 0.83 of an inch. Dividing I) /''(O 19) by D O (1 .5). the quotient is 0.127 ; multiplying \ of 0. 127 by :!.S6, \\\v. ])r<)<luct, the e.r.haiist-lap,\n 0.25 of an inch. Dividing N 11 (0.1) by 1.5, the quo- tient is 0.007 ; multiplving \ of 0.067 bv 3.S6, the product, the steam-lead, is 0.1 3 of an inch. Dividing" 7' 1^(0.375) by 1.5, the ([uotient is 0.25 ; multiplying A of 0.25 by 3.H6, the jiroduct, the exhaust-lead, is 0.4H of an incli. Adding the half-travel of the valve (1.93) to thr; width of the stcain-ixiH , 1.1, the sum is 3.03 ; Hui)tracting the width of the bridge (1.125), th(^ remainder, the width of the exhaust-port, is 1.91 in. TIks sum of the steam lap (0H3), the exhaust-laj) (0.25), and tlie width of the st,eam-i)()rt (1.1), thelinijth of the ralee-faee, iB2. IH inches. The sum of twice the length' of "face (1.3,6), twice the width of bridge (2.25), and the width of the exhaust-port ( 1.91 ), the leiajthofthe ralre, is 8.52 iiichcs. In this trxaniple no attempt has I)im'ii made to secure great accu- racy, and, as the measurements were made from a small sketch,
ENGINEERING. 83
tliere may be considerable errors. lu practice, a scale reading to hundredths of an inch should be used, and the figure should be constructed of full size, if possible. This can generally be done by laying down the positions of the crank in a small sketch, and then transferring them to a large drawing ; or the positions may either be calculated or taken from a crank-table, if one is avail- able. By making the drawing full size, and having marks on the shaft as described above, a template can be constructed from the drawing, for transferring the position of the eccentric to the shaft. It may be remarked, that however carefully the valve is proportioned and the adjustment of the eccentric effected, the en- gineer who desires to be certain that the valve-motion of his en- gine is properly arranged, will make the final test and adjust- ments with the aid of the steam-engine indicator. B.
Testing Small, Engestes. — The apparatus needed is quite sim- ple, and can be readily constructed by the young mechanic. The following embrace the principal points that are generally of in- terest in regard to engines and boilers : Diameter of cylinder, length of stroke, diameters of piston-rod, connecting-rod, crank- pin, valve-stem, fly-wheel, and shaft ; lengths of connecting-rod and crank-pin, weights of whole engine and of fly-wheel, size of ports, stroke of valve, point at which steam is cut off, number of revolutions per minute, clearance at each end of cylinder, pres- sure of steam in boiler, dimensions and weight of boiler, diame- ters of steam-pipe and safety-valve, number of pounds of water evaporated, fuel burned per hour, and power of the engine. Many of these data are obtained at once, by direct measurement or weight. The diameter of the cylinder should be measured when it is at the temperature at which it is ordinarily maintained while running. The point of cut-off can generally be ascertained by removing the cover of the valve-chest, and observing the point at which the steam-valve closes when the engine is moved by hand. This should be done when the parts are heated. The clearance at each end of the cylinder includes not only the space between the piston and cylinder-head at the end of the stroke, but also the volume of the ports. A simple and accurate manner of measuring the clearance is to fill the cylinder with water, when the piston is at one end of the stroke, and then measure the water carefully in a cylindrical or rectangular vessel. The dif- ference between the volume of the water and the volume of pis- ton displacement (area of piston multiplied by length of stroke) will be the clearance. In measuring the piston displacement at the front end of the cylinder, the volume of the piston-rod (area of section of rod multiplied by length of stroke) must, of course, be deducted.
The number of revolutions of the engine per minute can be de- termined approximately by observation ; but errors are apt to re- sult, especially in the case of small engines moving at a high rate of speed. Small shaft-counters can be obtained at a very reasona-ble price, and measurements made with them are far , more likely to be accurate.
Many small boilers are not provided with steam-gauges, so that the pressure of the steam can not be observed directly ; but all such boilers have, or should have, safety-valves, and the pressure of the steam can be determined from them. Secure the valve-
84 ENGINEERING.
stem of the safety-valve to the lever with wire or string, and at- tach a loop to the lever, into which pass the hook of an accurate spring-balance, arranging the loop so that it is directly over the centre of the valve-stem. Then take hold of the upper part of the spring-balance, and lift the valve slightly, noting the reading of the balance. Measure the lower diameter of the safety-valve, and find its area ; divide the reading of the spring-balance by the area of the valve, and the result will be the pressure, in pounds per square inch, at which the steam will raise the safety-valve. Suppose, for instance, that the diameter of the safety-valve is 1 inch ; its area will be about fiftn^ of an inch. Now, if the ten- sion of the spring-balance in raising the valve is 120 lb.s., the pressure at wliicli the valve will rise is the quotient arising from dividing 120 by ]Vi/(hi. or 153 lbs. per square inch. It will be easy to make a table for any particular case, giving the pressure corresponding to each pound or fraction of a pound of tension in the balance ; and by calculating in advance the reading of the balance for any given pressure, the weight can be adjusted on the lever until that tension is obtained, and the valve can thus be graduated to lift at anj' reijuired pressure. Having determined the pressure at which the safety-valve will rise when the boiler is cold, raise the valve by means of the balance, from time to time, when the engine is working, and observe the tension. Find the pressure corresponding to this tension, and subtract it from the pressure at which the valve will be raised by the steam. The difference is the pressure in the boiler at the time. For ex- ample, suppose that in the last case the tension of the balance, on raising the valve when the engine was working, was 50 lbs. The pressure corresponding to this will be 50 divided by r",fo%, or about 04 lbs., so that tlie pressure in the boiler at the time would be the difference between 158 and 04, or 8!) lbs. j)er sijuare inch. By preparing a table showing the pressure in the boiler due to each pound of tension in the spring balance, the pressure at any time can be read off as soon as the indication of the balance is observed.
The amount of water evaporated per hour and the fuel burned can, of course, be readily determined by measurement, drawing the water from a tank of known dimensions, and observing its state at the commencement and close of a trial, being careful to leave the water in the boib-r at the same height at which it was at the commencement, and maintaining this height as constant as possible during th(; experiment. In measuring tlie fuel con- sumed, it is best to draw out the fire at the commencement of the trial, rekindling it as soon as possible, and charging all the fuel used from that time, hauling and quenching tlie fire immediately at tlie closer of tin; trial, and weighing back all fuel that is uncon- suMKid. In the, case of Hinall boilers heated by lamps, a measure- ment of th«i oil used between the beginning and end of th(? trial will gi^nerally l)e suliicient ; and if gas is employed as fuel, it will h(! necessary to attach a meter to the pipts to determine the (|iiaiitity consumed in any given time.
'I'o asc(;rtain tin? power of the engine, the most convenient me- tliiid is, generally, to atta<h a friction-brake, shown in the ac- conipanying engraving, to the bund-wheel. Hollow out two pieces of wood, B and (.', so that they will tit the circumference of
ENGINEERING.
85
the band-wheel, A, and attach light plates of metal, D and E, to tlie sides, so tliat the pieces of wood can not slip off when secured in position. Provide two belts, F, G, countersinking the heads, H
TUE nUCTION-BliAKii.
and I. into the upper piece of wood, so that they can not turn, and put nuts and washers, K and L, on the other ends, so that the two pieces of wood can be clamped on the band -wheel as tiirhtly as is necessary. Make the upper piece of wood somewhat longer than the other, and pass a rod, M, through the end. On this rod weio^hts, N, are to be placed, and the lower end of the rod is hooked to the piston-rod of a small cylinder. O. The pis- ton, P, fits loosely in this cylinder, which is filled with oil or wa- ter ; and the piston has small holes in it, so that it can move up and down without much resistance, if moved slowly, but offers considerable resistance to sudden motion. The action of the ap- paratus will doubtless be apparent to our readers. By tightening the nuts on the bolts, F, G, there will be considerable friction be- tween the band-wheel and the pieces of wood. The rod M must then be loaded with sufficient weight, so that the engine can just move at its regular rate of speed, and keep the npper piece of wood in a horizontal position. The friction on the band-wheel will cause it to become heated, unless some arrangements are made for cooling, either by keeping a stream of water running upon it, or immersing the lower part in a trough in which the water is constantly changed. The small cylinder, O, and piston, P, serve to counteract the effect of sudden shocks, which would otherwise throw the arm of the piece B from a horizontal position. Now it will be plain that, as the band-wheel revolves (constantly maintaining the arm, with the weight attached, in a horizontal position), the effect is the same as if it were lifting this weight by means of a rope running over a windlass, and the distance through which it would lift the weight in a given time is the same as the weight would move if the whole apparatus were free to revolve. If, for example, the wheel makes 300 revolutions in a minute, the distance from the centre of the wheel to the centre of the weight is 1 foot, and the weight is 10 lbs. ; this weight, if free to revolve, would move in each revolution through the cir-
86 ENGIXEERING.
cumference of a circle whose radius is 1 foot, and in a minute W'luld move 300 times as far, or about 1885 feet. The work of the ensrine in a minute, then, will be that required to lift. 10 lbs. through a heifrht of 1885 feet, or 18.850 foot lbs. ; and as one horse-power is the work represented by 33,000 foot lbs. per min- ute, the engine would be developing a little more than half a horse-power.
In makinj; experiments with the friction-brake, the apparatus should be placed loosely on the band-wheel ; and before the weights are attached, a spring-balance should be secured to the arm, at tlie centre of the hole for the rod M, and the reading not- ed when the arm is in a horizontal position. This reading must be added to the weights that are afterwards attached. The hori- zontal distance from the centre of the wheel to the centre of the rod M, should be carefully measured. Then start the engine, with the throttle-valve wide open, and screw tip the nuts K L gra- dually, adding weights at X. It will then only be necessary, when sufficient weights are added, to keep the wheel cool, and occasion- ally adjust the nuts K L, should the brake bind or become too loose from any cause. Should it be difficult or inconvenient to maintain the arm in a horizontal position, note carefully the posi- tion it assumes during the test ; and for the radius to be used in the calculation, measure the distance a h from the centre of the wheel to the centre of the rod M, in a direction perpendicular to the direction of the rod.
Instead of the weights, N, and cylinder, O, a spring-balance may be attached to the end of the rod M. and secured to some fixed support, its readings during the trial being used in place of the attached weights. In this case, also, the weight of the apparatus must be first determined, and added to the readings of the spring- balance. The plan represented in tiie engraving is, however, the best.
Tlie above are, in detail, the methods to be pursued in pre- paring a report of the i)orformancc of small engines and boilers. Although they are far from fullilling all the requirements of a scientific test, they will give very accurate results if carefully conducted. B.
TruRiNE WiiEET.s. Effective power of. — It is important, in se- lecting a good wheel, to be assured that it will furnish amjjle power. After ascertaining a reliable maker, in order to determine the exact size of the whet^l it is necessary that at least one third should be allowed for variations in water levels, and for the lo.ss consecjuent to the wear of wiicels and gates; an<i, in addition, figures should be made, based on but a little mere tluui a half gate of water to the wheel. The best wheels afford almost all of their power at a five-eighths gate or under, and a difference be- tween a half and full gate is not more than sliould l)e the margin necessarv to regulate sjieed. In use it will be found that open- ing gates seven-eighths or fully simply amounts to a large consuin]>tion of water, generally without producing five orten jht cent additional power. Some good wheels give less p)wer when at full than at i)art gates. The rule should be to buy a wIuhO amply sulHcient at not much above half gate, allowance being madi- for overestiiuat.- of power. We think the e\]ierieiu-e of all who have jdaci-d whe«-ls w ith a less liberal allowances will bear
BNGIXEERING. 87
out and confirm this rule. Allowing one fourth for the friction of the sliaftint; of a cotton or woolen mill, without addinfj one third more for a reserve when in actual use, will scarcely fail to cal^se a manufacturer to wish that he had bought a larger wheel. Actual tests, accurately conducted, of ol styles of turbines show the comparative range of effective force, under the best possible advantages, to be as follows : At quarter gate, from 13 to .50 per cent ; half gate, from 11 to 71 per cent ; three-quarter gate, from 31 to 82 per cent, and at full gate, from o2 to 84 per cent, the best wheels giving out about all of their power at from five-eighths to three-quarters openings ; while the lower classes give but little power unless flooded with water, and even then fall far short of the amount claimed for them. Another reason why large wheels should be used is that, almost universally, high and low points of the head and tail waters so reduce the force of wheels as to cause partial stopjaages of machinery, unless there is surplus power when the water is at the ordinarv stage.
THE STEAM-BOILER AXD ITS ATTACHMENTS.
Boiler, Cleaning the. — The flues or tubes of a boiler should be cleaned about once a week, with a brush or scraper. In case incrustation has formed in them, they can be cleaned by a jet of steam from a rubber hose. A boiler should be blown down and cleaned, under ordinary circumstances, about once a month. The fire should first be hauled ; and then, if possible, it is best to let the boiler stand tintil the water becomes tolerably cool, say for 12 hours, after which the water may be allowed to run out. Then remove the man and haudhole plates, enter the boiler, and clean it with scrapers and brushes in every part that can be reached. It should then be washed out with cold water from a hose, and this washing with a hose is the only means of cleaning those parts of a boiler that can not be reached by hand. There are many boilers into which a man can not enter, and of course these can only be washed out. When the fire is hauled, all leaks in the boiler should be repaired. Leaky parts exposed to the fire must have hard patches riveted on ; in other places soft patches secured by bolts can be used, each patch having a lip around it, and the joint being made with a putty composed of red and white lead. Leaky rivets or seams can sometimes be made tight by calking. Small leaks around the ends of tubes can often be stopped in the same way, but as a general thing a leaky tube must either be replaced or plugged. To plug a tube, drive a white-pine plug tightly into each end, and cut it off even with the tube-heads ; then pass a bolt through the tube, with cup washers on each end, and screw it up tightly, putting putty under the washers. B.
Boilers, Cylindrical. — Toflndthe necessary tliickness in inches for the shell. — Multiply the pressure of steam in pounds per square inch by the diameter of the boiler in inches, and multiply this product by 0.0002 for a copper boiler with single-riveted shell ; by 0.0001563 for a copper boiler with double-riveted shell ;
88 ENGINEERING.
by 0.0001316 for a wrouglit-iron boiler with single-riveted shell ; by 0.0001111 for a wrouo^ht-irou boiler with double-riveted shell ; by 0.0001 for a steel boiler witli single-riveted shell ; and by 0.00008333 for a steel boiler with double-riveted shell.
In illustration of the rule, suppose that it is required to find the necessary tiiickuess for the shell of a copper boiler 60 inches in diameter, double riveted, for a pressure of 40 ll)s. per square inch.
First take the product of 40 and 60, which is 2400, and multiply this by 0.00()ir)63, which gives 0.375, or 'j of an inch, as the neces- sary thickness.
To find the safe pressure in pounds per square inch. — Divide the thickness of the plate in inches by the diameter of the boiler in inches, and multiply the quotient by 5000 for a copper boiler with single-riveted shells ; by 6400 for a copper boiler with double- riveted shell ; by 7600 for a wrought-iron boiler with sini^^le-rivet- ed shell ; by 9000 for a wrought-iron boiler Avith double-riveted shell ; by 10,000 for a steel boiler with single-riveted shell ; and by 13,000 for a steel boiler with double-riveted shell.
Thus, to find tlie safe pressure for a boiler 33 inches in diame ter, the shell being made of wrought-iron plates \ of an inch thick, single-riveted : First divide -^ by 33, which gives i^^, and multiply this by 7600, the product, 59g^ lbs. per square inch, being the ])ressure required.
Thickness, in inches, of flat heads (not stayed). — Multiply the scjuare root of the pressure in lbs. per square inch by tlie radius of the shell in indies, and by 0.013333 for a head of copper ; by 0.010541 for a head of wrought-iron ; and by 0.0081649 for a head of steel.
A steel boiler has a diameter of 24 inches, and the pressure of the steam is 60 lbs. per square inch : The thickness of the head is the product of 7.746 (the square root of 60), 12, and 0.0081649, which is equal to 0.7766, or about ;i| of an incli.
Safe pressure, in pounds per scpiare incJi, for flut heads (not stayed). — Divide the square of the tliickness of the plate in inch- es bv the square of the radius of tlie shell in inches, and luulti- plv the (luotient by 5625 for a head of cop])rr ; l)y !)000 for a liead of wrouglit-iron ; and by 15.000 for a head of steel.
Suppose the heads of a boiler are of steel, I inch in thickness, and that the diameter of the boiler is 24 inches : .25 (the square of \), divided l)y 141 (the squan^ of the radin.s), is .00174, and the l)roduct of .00174 and 15,000, 26 lbs., is tin; iiressun; required. H.
Bf)ri.KKs, Heating surface of. — Note : In lln' following rules all dimensions ar<i to be taken in feet.
(a) (U/lindrical boilers. — Take the product of (1) tlie diameter of tlie boiier, (2) the length of the boiler, and (.3) 1.5708.
Sii])]iose n given boiler has a diameter of ;56 inches, and a h'Mirh of 20 feet, its lieating surface is the product of 3, 20, and 1.5708, or about 94J scpiare feet.
(h) Cylindrical flue boilers. — Take the product of the diameter of the boih-r, the'length, and 1.5708, and add it to the product of (I ) interior diameter of line, (2) length of line, {;]) number of ihu'S, an<l (1)3.1416.
Snp])ose that a line boiler is I feet in dianietei-, 22 feet long, and has two flues, each with an interior diameter of 15 inches. Then the heating surface is <'qual to the jiroduct of 4. 22, and 1.5708, or
I
KNGIJVEEBING.
89
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Internal surface in square inches, per foot of length. |
i> CO CO OJ l- iO Ci iO Ci CO t^ iO CO QO IC CQ i> t-~ |
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Internal surface in square feet, per foot of length. |
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outside siirfiice in square inches, per foot of length. |
T-l lO 1-1 ■* 00 O? t^ tH O '^ GO £>• 1.-5 tH 05 00 CO |
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£-ooira-Tt<'*cocoojcQi-ic;CiOOOco-rtC5i^ ■^iOOl-COOSO-^OlCO^lOOOOC^JOOCOt- ■i-lT-lTHrH-T-li-lT-li-lOJOiCOCOCO |
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Outside surface in square feet, per foot of length. |
0}l--0iO-rH10 '^CSCOOCC^i-H QOO'+O'J t-0^'»COCS'* 100»T-Ht-OOCSOCQ^OGO o:? Ci iO C? CO lO IN GO LO 1-H 00 ^ £> O fi CO C; O i-i CO 0^ ^ O O CO t- L- CO C3 C5 O T-H CO iO 00 O CO o |
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Internal diameter in feet. |
Ol 00 £- *7 00 00 1- iC t^ irti GO Oi lO CI T-H O ^ O rH ^ o -^ C» -^ C? 01 o? »o cs o C5 ^ CO lO £^ C5 T^ CO O I- C5 -rt »0 C: t- lO CO CJ C5 Ot-HT-li-iTHTHC^OiWO^OJCOCOCOTitiOOC^t.^ |
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Internal diameter in inches. |
OOOCOt-HCOOOCOOOt— lO-i-HCOCOOl:^i>-f>^GS T-H CO iO GO O SQ O I- O C? lO t- (?} £^ «? O O O iO |
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Thickness in inches. |
(W CO J-O Lt! iO C5 O CJ -^ -^ CO l--:! IC lo co C-GOClCiOSOOOiNOJCJCOCO-^OCOOOOO OOOOOi-HT--,-l,-l,-ITH,-,,-lrH,-H,-l^rHCJ OOOOOOOOOOOOOCJOOOOO |
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Outside diameter in feet. |
c^ 00 c- lo CO ffj 00 i> »o CO t~ CO I- CO '^iOlfflCOf^OOO Ot-iWCOIOO coo CO OOJ-^OOOO'MlOt-CS-'-HCOl^— 1 OOOIOCO ,-1 ^ -rt ^ T-H C"* O"? 0> Oi Ol CO CO CO ^ l.t' <o O t^ GO ooooooooooooooooooo |
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Outside diameter in inches. |
lO to lO ,_ »0 lO LO OJJCt- CQlOt- CQiOt^ lO ^' T-H ,-; (N oj <?:(■ ei CO CO CO CO -# ^ lo o i^ 00 ej o T-H |
90
ENGi:SEEEING.
nearly 138i, increased by tlie product of 1.25, 22, 2, and 3.1416, or about 172f, making tlie total lieating surface 311 square feet.
(c) Cylindrical tubular boilers. — Find the product of the diame- ter of the boiler, the length, and 1.5708, and add this to the pro- duct of the length of the boiler, the number of tubes, and the heating surface of a tube per foot of length.
The preceding table gives the heating surface per foot of length for the standard sizes of tubes.
LOCOMOTIVE liOlI.ER.
JSxample. — A cylindrical tulmliir boiler has a diameter of 42 inches, is 10 feet long, and contains 40 tubes, each 4 inches out side diameter.
The i)roduct of 3A, 10, and 1.5708 is nearly 88.
The i)roduct of 10, 40, and 0.977 (the internal surface of the tube, p(M- running foot) is about 015, so that the -whole heating surfaces is 703 s(|uare feet.
((I) Lorimiotin' hi'ilcrx. — I. Add together the following cjuanti- ties : (1) Tlie product of the length of tin- line l)()unding the croHH-section of t lie furnace, and the length of the furnace. (2) Twice the area of the cross-section of the furnace. (3) The pro- duct of the hiiigth of the tubes, the niunber of tubes, and the heating surface of ii tube per foot of lengtli.
II. Sul)tiiict from tliis sum tin' sum of the following (piauti- ties : (I) Tlie area of the lurnace-door. (5) Tlie product of the luiMiber of tu])e8, the Hcjuare of the iMternal dianuitcT of a tube, and 0.7H54.
ENGINEEEING.
91
As an e'xample of the use of this rule, suppose it is required to determine the heating surface of a boiler having tlie dimensions noted in the entrravinfrs. Fig. 1 being a cross-section of the
L( ICOMOTIVE BOILEK.
boiler at the furnace, showing also the furnace door iu dotted outline, and Fig. 3 a longitudinal section. (1) The length of the line bounding the cross-section of the furnace is the sum of twice 3.5, 1.5708, and 3.5, or 11.07, and the product of 11.07 and 4 is 44.28. (2) The area of the cross-section of the furnace is the sum of 3.5 squared, 2i times +, and 0.7854 divided bv 2, or about 13.89. Twice 13.89 is 27.78. (3) The product of 8, 20" and 0.977 is 157.32. The sum of 44.28, 27.78, and 157.32 is 229.38. (4) The area of the furnace-door is the sum of 1.5 times 1.25, and 0.3927 times 1.5 squared, or about 2.76. (5) The product of 20, 0.311 squared, and 0.7854, is about 1.52.
The smn of 2.70 and 1.53 is 4.28. The difference between 229.38 and 4.28 is about 325 square feet, tlie heating surface required.
(e) Vertkal boilers. — I. Take the sum of the following quanti- ties : (1) The product of the diameter of furnace, height of same, and 3.1416. (2) The product of the diameter of the furnace squared and 0.7854. (3) The product of the number of tubes, length of same, and heating surface per foot of length.
II. Subtract from this sum the product of the number of tubes, the internal diameter of a tube squared, and 0.7854.
Example. — Required, the heating surface of a vertical boiler with the following dimensions : Diameter of furnace, 24 inches ; height of furnace, 18 inches ; 40 tubes, each 3 inches outside di-
92
ES^GLfiEEBlXG.
ameter, 6 feet long. (1) The product of 2, 1.5, and 3.1416 is 9.43. (2) The product of 4 and 0.7804 is 3.14. (3) The product of 40, 6, and 0.4739 is 113.74. The sum of 9.43, 3.14, and 113.74 is 126.3. The product of 40,0.02374 (the square of 0.1508), and 0.7854 is about 0.73. The heating surface is the difEerence be- tween 126.3 and 0.72, which is about 125.6 square feet. B.
BoiLEKS, Horizontal, Setting. — The best way is to have the fire-box at least as wide as the boiler, and have as much heating surface as possible ; but below the water-line all passages should be made large, so as to allow a free passage to the heated gases, and where they leave the boiler, a damper should be provided. The bridge-wall should be high enough to prevent coal from being thrown over, and the grates low enough to allow ample room for combustion. Nothing can be gained by putting the fire near the boiler or contracting any of the passages ; it is better to let the heat diffuse itself fully throughout the entire heating surface.
Boilers, Priming in. — If your boiler primes, either " swap" it off for another or superheat your steam moderately ; but beware of anti-priming doctors and their remedies.
Boilers, Rules for firing under. — (1) Begin to charge the fur- nace at tlie bridge end, and keep firing to within a few inches of the dead-jjlate. (2) Xever allow the fire to be so low before a fresh charge is thrown in, so that there shall be at least 4 or 5 inches of clear, incandescent fuel on tlu- l)ars, e(iually spread over the whole. (3) Keep the bars constantly and equally covered, particularly at the sides and bridge end, when^ the fuel burns away most rajmlly. (4) If the fuel burns une(]ually or in holes, it must be leveled and the vacant spaces filled. (5) The large coals must be broken in ])ieces not larger than a man's fist. (6) Wliere the ash-])it is shallow, it must fr(M|U('ntly be cleaned out ; a bodv of hot cinders will overheat and burn the bars.
■^^^'
ll illlllliiPiil
ffl:
C'lilMNKYS, To Htraighten tall. — Ilnve a number r)f oak wedges made of HuHicient lenglli to pass through tlu-, entire thickness of
ENGINEERING. 9^
the chimney and project sufficiently on the outside. Place them in sets of three each, one over the other, as shown in the en- graving, having the surfaces in contact straight and smooth, and black-leaded to diminish friction. Commence on the oppo- site side to that in which the chimney leans ; cut through to the inside, insert one set of wedges, and wedge above and under them until they take a bearing. Repeat the process around the chim- ney, except on the lowest side, leaving spaces of a foot or more between each set of wedges. Then, by driving the centre wedge in each set inwards, as much of the chimney as rests on them is gradually lowered just at the places and to the amount required to bring it to an exact perpendicular. When that is done, brick up the intervening spaces, loosen and withdraw the wedges, and brick up in their places. This requires careful and skilful work.
Chimxeys, Proportioning. — The general rule is to make the cross-section of the chimney, which maybe either round or square, from ^ to Yjf of the grate-surface, and the height from 50 to 70 feet.
To determine the amount of coal which will be burned per square foot of grate per hour, with good proportions, by Professor Thurs- ton's rule. — Subtract one from twice the square root of the height. Example : What will be the amount of coal burned per square foot of grate surface per hour, the chimney being 49 feet high, and suitably proportioned ? The square root of 49 is 7 ; twice 7 is 14 ; 14 less 1 is 13, which is the amount of coal required in pounds.
To determine tJie height required to give a certain rate of com- bustion.— Add 1 to the weight to be burned per square foot per hour ; divide by 2 and square the quotient. Example, same as above, worked backwards, thus : What height of chimney is re- quired to burn 13 pounds of coal per square foot of grate sur- face per hour ? 18 and 1 are 14 ; 14 divided by 2 is 7 ; the square of 7 is 49, which is the height of the chimney in feet.
Co.\L, Effect of damp air on. — It has been found by recent experiments on this subject, that the loss in weight, dite to a slow oxidation and to the disengagement of gases which form the richest part of bituminous coal, may equal one third of the ori- ginal weight. The heating power in such coal was lowered to 47 per cent of its former capacity. The same coal exposed to the air, but in a closed receptacle, did not lose more than 25 per cent of gas and 10 per cent of heating power. Bituminous coals alter most rapidly. This shows the disadvantage of damp cellars, and of leaving coal uncovered for long periods and subject to bad weather.
CojrBUSTioN AND FuKL. — The principal constituents of coal are carbon, hydrogen, water, a little sulphur, ashes and clinker, the latter two substances consisting generally of silica, alumina, iron, lime, magnesia, and oxide of manganese. The principal combus- tible constituent of anthracite is fixed, uncombined carbon. The free-burning or semi-bituminous coals contain a considerable amount of hydrocarbon or volatile combustible matter, and bitu- minous caking coals have a larger percentage of volatile combus- tible.
If a mass of coal is brought to a sufficiently high temperature
04 ENGINEERING.
(probably something above 1000' Fahr.), the combustible mate- rials enter into chemical combination, and as much heat is given out as would be required to decompose the resulting products into their elements. When coal is burned the water is first expelled ; then the sulphur, if any is contained, is consumed, forming sul- phurous oxide ; after this the hydrogen in the volatile combusti- ble matter unites with oxygen, forming water ; and the carbon set free unites with oxygen, forming carbonic dioxide, if the tem- perature is sutliciently high and enough oxygen is present, or, under less favorable circumstances, either forming carbonic oxide or passing off unconsumed, as soot. The combustion of the fixed carbon next begins, the product of the combustion being carbonic dioxide or carbonic oxide, so that liually nothing is left except the ashes and clinker.
It may be well to trace the effect of these various combina- tions : The water contained in the coal is expelled in the form of steam, so that it carries off some heat, and is a positive disadvan- tage. The complete combustion of a pound of sulphur produces about 4000 units of heat, but the amount of sulphur in coal is usually so slight that its heating qualities scarcely disserve to be regarded. The action of tlie sulpliur on the material of the boiler is, however, a very serious matter. It has not yet been determin- ed by experiment what per cent of sulphur is sufficient to render a coal unfit for use in a furnace, but it is well known tliat "many of the Western coals produce very bad effects when employed in locomotive boilers. A pound of hydrogen combining with oxy- gen, forming 9 pounds of water, has a heating power of 02,033 units. It seems doubtful, however, whether this amount of heat is available from tiu; combustion of hydrogen in a boiler. The experiments by which tliis value was determined wer(> made u])on liydrogen in the gaseous stat(i, and the steam resulting from the combustion was condensed. Now tiie hydrogen in coal is ordi- narily combined with carbon, and frequently with nitrogen, so that it must b(; separated from the coiul)ination l)efore it can be united with oxygen, and heat is required for this separation. •Vgain, in a boiler thr ])rodu<;ts of combustion usually pass into llu; chimney at such a iiigh ti^mptu'ature tluit the water, wiiich is tlie result of the combustion of the hydrogen, jjasses off in the form of steam, and thus carries off a considerable (luantity of wliat is coinmr)iily known as latent heat. Tiiis subject is one vvhicli liiis been but little considinvd by experimenters, and is worthy of more extcMuhjd inv(^stig;itioii. The volatiit? comljusti- bh; matter of i-oal generally contains oxygen in comliination, and tiiis must b(! ciiangi'd into the gaseous state before being unittid with the hydrogen, an operation that n^quires as much lieat as results from tlie new combination, llciiice it is <rertain that tlio amount of liydrogen contained in coal must be (limiiiished by one eiglith of the weight of the oxygen liefore attempting to form any estimate of its heating ipialities.
The cariion of llie coal, as has been aln^ady stated, will unite with oxygen, forming (carbonic dioxide, and may afterwards lake U|) more carbon, hik! lie converted into carbonic oxide. Now the re.-tull of the coiiipleti- combustion of a pound of curb m is I'ji lbs. of cariioiiic dioxide, and the cimilmstion piodiices 11,000 units of heat. But a pound of carbon iiiiperfcictly Imrned produces 2J-
ENGINEERING.
96
|
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10 |
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CI 1—1 |
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10 |
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piinod ono Aq 'o?lE i^ put! uio.ij •pajBJodBAB aajBAi jo sp;inOc[ |
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96 KNGINEEEING.
pounds of carbonic oxide, and only 4400 units of heat. In a fur- nace where the combustion is imperfect, tlie action is iisually as follows : A pound of carbon is at first completely burned, fori-iung 3| pounds of carbonic dioxide, and then takes up another pountl of carbon, producing 4^ pounds of carbonic oxide and 8800 units of heat. This carbonic oxide, however, if supplied with a suffi- cient amount of air, will burn and again form carbonic dioxide, so that the full effect of the combustion of the carbon will be realized. A practical application of this principle is seen in the combustion-chambers in boilers, which are designed to complete the combustion of the gases after they leave the furnace.
Having disposed of the materials of the coal which escape into the chimney of a boiler, the ashes and cliulier that remain should be considered. The effect of these substances is injurious in se- veral ways : they choke up the furnace, preventing free access of the air to the combustible materials, and instead of entering into combinations and producing heat, they require to be heated to the temperature of the furnace, and are then removed, without hav- ing produced an equivalent for the heat expended ujion them.
In ordinary boiler-furnaces, the amount of air required for the combustion of 1 pound of coal is about 24 pounds, or between 280 and 300 cubic feet.
For a table of the qualities of American coal from various loca- lities, compiled from Prof. Johnson's Report, see page 95. B.
Feed-Wateu Heaters, Gain from the use of. — A unit of heat is the amount of heat required to raise the temperature of a pound of water one degree, the water being at th(^ temi)erature of maxi- mum density, about 39.1° Fahrenheit. The table below shows the number of units of heat required to convert one pound of wa- ter, at the temperature of 32", into steam of various pressures.
|
Pressure of steam |
Pressure of steam |
||
|
ill 11)9. per sq. in., |
Uoitsof hetit. |
in 11)8. per 8<i. in., |
Units of Iieat, |
|
by gaii-;e. |
by gauge. |
||
|
1 |
1148 |
10 |
1155 |
|
20 |
1161 |
30 |
1105 |
|
40 |
1169 |
50 |
1173 |
|
GO |
1170 |
70 |
1178 |
|
80 |
1181 |
90 |
1183 |
|
100 |
1185 1189 . . . . 1192 |
110 |
1187 |
|
120 |
130 |
1190 |
|
|
140 |
150 170 |
1193 |
|
|
100 |
1195 |
1190 |
|
|
180 |
1198 |
190 |
1199 |
|
200 |
1200 |
In a non-condensing engine, if the exhaust steam escapes di- rectly into tiu! atmospllen^ it carrii-s off most of the lieat tiuit was |)reviously iiiipiirte<l to it by the coai in the furnace. This may l)e illustrated i)y an exain|)ie.
Suppose the steam is admitted into the cylinder of an engin(! at a pressurt! of 90 poiiiids ])er s(|uare inch, and exhausted at a pres- sure of 1 pound above the atmosphere, and that the temperature of tlie fi-i-d water is 70 . if the f.-ed wiiter had l)een at 32', it will he seen that eacli jjound of water would have re(|uire(l 1183 units yf heat to convert it into steam of !)(» jiounds pressure ; but since
ENGINEERING. 97
tlie temperature of the feed was 38" above 32°, 38 units less, or 1145, will be necessary. The exhaust steam carries away 1148 less 38, or 1110 units of the heat that has been imparted to the steam by the coal, so that about 96.94 per cent ot the heat is thrown away. Now, it costs money to heat this water, and the steam-user who pays $6.50 a ton for coal, which converts 15,000 pounds of water into steam, might make up an account some- what after this manner: "After evaporating 15,000 pounds of water at a cost of $0.00043+ per pound, I allowed 14,541 pounds to escape into the air without rendering me any equivalent, and only utilized 459 pounds in my engine ; so that really I pay at the rate of $0,014+ for every pound of water used."
There are many steam-users to-day who could readily make up an account somewhat like the preceding.
Now suppose that the steam-user, being convinced of the folly of paying for coal to raise steam wliich is blown away without doing any good, attaches a heater to his exhaust-pipe, and so raises the temperature of the feed-water to 300', instead of TO'', as before. If this is done, and the heater is a good one, which does not increase the back pressure, each pound of water requires 130 units less for its evaporation, and each pound of exhaust- steam carries away 130 units less than before ; and the steam-user can make up his account anew, as below :
"One ton of coal now evaporates about 16,900 pounds of water, at a cost of $0.00038 per pound, and 600 pounds of this water are utilized in the engine ; so that 1 now pay $0.0108 for each pound of water that produces useful effect."
If he had an engine of 100 horse-power, using 30,000 pounds of steam a day, and working 300 days in a year, he would find that the difference in his coal l)ill, before and after the change, would be the difference between $3870 and $3420, or $450. B.
Fire-Clay for boiler-furnaces. — Take common earth, well mixed with water, to which is added a small quantity of rock- salt ; let the water stand until the salt dissolves, which will take about 2 or 3 hours. It is then ready for use. Apply it as fire- clay is used, and your furnace will stand much longer.
Flue-Sheets, To calk leaks in.— Use a reflector (a tin plate will do) adjusted in front of the furnace-door, so as to throw light on to the flue-sheets, while calking leaks.
Flues, Whovgkt-Iros.— Thickness in inches of a wrought-iron flue exposed to external pressure : I. Find (1) the product of the diameter of the flue in inches, (2) the length of the flue in feet, (3) the pressure of steam in lbs. per square inch, and (4) .000,009,091.
II. Extract the square-root of this product.
Suppose, for example, that a flue is 12 inches in diameter and 6 feet long, and that the pressure of steam is 40 lbs. per square inch : The product of 12, 6, 40, and 0.000,009,091 is about 0.02618, and the square-root of this number is 0.1618+, or about -j4j of an inch. It will be observed that the thickness of a flue increases directly as the length. Thus, other things being equal, a flue that is 12 feet long must be twice as thick as one that has a length of 6 feet. In making long flues, it is common to strengthen them at intervals by bands, thus converting them into a series of short flues, so far as the strength is concerned.
98 ENGINEERING.
Safe pressure in lbs.j)cr square inch for a wroxght-ircn flue exposed to external j)ressure : Multiply the squsire of the thickuess in inches bv 110,000, and divide this product by the product of (1) the diameter of the flue in inches, and (2) the length of the flue in feet.
Exeimple. — What is the safe pressure for a flue 15 inches in diameter, 8 feet long, and f of an inch thick '?
The product of 0.140,625 (the square of the thickness) and 110,- 000 is 15,468.75. Dividing this by 15 times 8, or 120, the quotient i.s about 128.9 lbs., the pressure required. B.
Gauges, mercurial steam. Keeping clean. — This can be done by putting a little glycerine or sulphuric acid on the surface of the mercury. This serves as a lubricator of both glass and metals, and prevents their adhi'sion.
(tauges. Water and steam. — When a boiler is in use, the gauge-cocks should frequently be tried to see that they are not choked up, and the glass gauge should often be blown out. After ascertaining the proper place iov tlie weight on the lever of the safety-valve, a stick should be secured to the lever with wire, so that the l)all can not be moved out any further. A cord should be secured to the safety-valve lever, within easy reach of the engi- neer, so that the valve can be opened by hand if it sticks, and the safety-valve should be tried at least once every day, to ascer- tain whether or not it is in working order.
A steam-gauge should be tested at least once a year, and the engineer should frequently try its accuracy by allowing the steam to raise the safety-valve, and noting the pressure shown by the gauge. The hand of a steam-gauge sometimes sticks, and the engineer should taj) the face of thegauge lightly several times a day, to assure himself that it is in working order. He may also shut off the steam from the gauge-pijje, and open the drip- cock, noting whether the hand goes back pronijttly to 0, and re- turns to the former reading when steam is again turned on.
In testing a boiler, warm Avater should be used, and a better test, when this is possible, is to enter the boiler and make a tliorough internal examination.
In leaving a l>()iler for tin- night, the fire may either be hauled or banked. If it is to be l)anked, it should first be cleaned and then puslied back and covered with coal, the b(»iler being left with the furnace-door open and the damper closed. B.
Joints, Rivktkd, Proportions of. — {a) Diameter of riret in inehes : Multiply the thickness of plate in inches l)y 3 for plates up to f of an inch thick, by 1.5 for plates from f to J of an inch thick, by 1.25 for jilatr-s from § to J of an inch thick, and l)y 1.125 for plates from J to 1 inch thick.
{h) Lemjth <f rirrt iinder the head, in inches : Multiply the tliicknesrt of the ]>hite in ini'hcs by 4.5.
{c) Distance between ricets, fnnn centre to centre, in inches : (1) Sinf/lc-rire.led joi/its : Multii)ly the thickness of jilate in inches by (! for ])lates up to J of an inch thick, l)y 5 for plates from ^ to 8 of an incli thick, by 4 for ])Iates from | to | of an imh lliick, and by :{ for platfs from i, to 1 inch thick.
(2) /'Jach line of rirets, (fmtldi -rirefed Juiiits : -Multiply the tliicl;- uoss of the plate in inches by 7 for plates up to i of an inch thick,
ENGINEERING.
99
by 6 for plates from J to -j^- of an inch tliick, by 5 for plates from uf to Tb' of an inch thick, and by 4 for plates from t^^ to 1 inch thick.
(d) Lap to be given to joint, in, inches: (1) Single-riveted joints : Multiply the thickness of plates in inches by 6 for plates up to f of an inch thick, by 4.5 for plates from |- to f of an inch thick, and by 4 for plates from f to 1 inch tliick.
(2) Double-riveted joints : Multiply the thickness of plate in in- ches by 10 for joints up to f of an inch thick, by 7.5 for joints from I to f of an inch thick, and by 6.7 for joints from f to 1 inch thick.
A table is appended, giving the thickness of plate in decimals of an inch, varying by sixteenths :
|
Halves. |
Fourths. |
Eighths. |
Sixteenths. |
Decimals. |
|
1 |
1 3 |
1 |
0.0625 |
|
|
3 |
0.125 |
|||
|
3 |
0.1875 |
|||
|
4 ...:..:.. |
0.25 |
|||
|
2 |
3 |
5 |
0.3125 |
|
|
6 |
0.375 |
|||
|
4 |
7 |
0.4375 |
||
|
1 |
8 |
0.5 |
||
|
3 4 |
5 |
9 |
0.5625 |
|
|
10 |
0.625 |
|||
|
6 7 |
11 |
0.6875 |
||
|
12 :.. . |
0.75 |
|||
|
13 |
0.8125 |
|||
|
14 15 |
0.875 |
|||
|
8 |
0.9375 |
|||
|
3 |
16 |
1 |
||
The following example will serve to illustrate the rules : What should be the proportions of a single-riveted joint for a boiler made of plates -| of an inch thick V
Diameter of rivets is twice 0.125, or J of an inch. Length of rivets under head is 4.5 times 0.125, or -,\- of an inch. Distance between centres of rivets is 6 times 0.125, or f of an incb. Lap of joint is 6 times 0.125, or f of an inch. B.
Lead, Effect of steam on. — Lead iu contact with steam under pressure of over 10 lbs. per square inch very soon loses its strength, and it is therefore good neither for packing joints nor for conveying steam.
Pipes, Steam, Burst. — Steam-pipes which have cracks in them from having burst, may be repaired by heating and then soldering them.
Pipes, Ste.\m, Condensation in subterranean. — To prevent this, inclose the pipe in another larger pipe, and fill the space between the two with plaster-of-Paris or charcoal. The outside pipe should be water- tight.
Pipes, Steam, Isolating material for. — Take 182 lbs. limestone, 385 lbs. coal, 275 lbs. clay, and 330 lbs. sifted coal-ashes. This is finely pulverized, and mixed with 660 lbs. water, 11 lbs. sul-
100 ENGINEERING.
phuric acid at 50" B., and about 160 lbs. calves' hair or liog- bristles. Tlie compound is applied to the pipes in coats of 0.4 inch thickness, repeated until a thickness of an inch and a half is obtained, when a light covering of oil is given.
Pipes, Steam, To prevent cracking, from freezing. — Steam-pipes apt to fill with condensed water and burst from freezing should have small holes with plugs to them, the plugs to be taken out at night.
Sawdust as Fuel, To burn. — A saw-mill owner solves the problem of using saw-dust as fuel as follows. His boiler was a return tubular, 14 feet 0 inches long and 54 inches in diameter, with 04 three-inch tubes, and brick firebox 48 x 56 x 27 inches high ; bridge- wall was 7 inches at centre, rounded to the sides of boiler. He states : "I lowered the bridge-wall 13 inches (keeping the same circle as before), lowered the paving in rear of firebox to a level with the grate-bars, and obtained a barrel of furnace-slag from 3 to 7 or 8 inches in size and 1 or li inches tliick, which I placed on the grate-bars, about half covering them. I fired with wood ; and when the slag got heated, I threw in the sawdust, which burned very well but smoked fear- fully (clouds would arise from the smoke-stack). I then intro- duced a 21nch pipe, with about fifty ^-inch holes, directly behind the bridge-wall, leaving l)oth ends of pipe open ; after which, I never had a particle of trouble either in keeping up steam or in burning up the smoke. Not even in firing up did I ever see any smoke come out of the stack, which was 30 feet high and 32 inches square, enlarged near top and to the top to 30 inches in- side measurement. I forgot to state that I covered the top of boiler with sheet-iron, tlien laid brick on it, covering the inter- stices with sand. The sheet-iron was to prevent the sand from wedging off the wall when tlie boiler expanded." A system of alternate firing, and with grates so arranged as to peimit some charred fuel to fall througli and burn in the ashpit, gives the best results.
Scale in Stkam-Boflers, Prevention of. — (1) Use as pure water as your locality affords. (3) Clean and scrape your boiler as often as you possibly can. (3) Blow off without excess. (4) In case of salt or brackish waters, never use steam of over OO lbs. i)ri'.ssiir(^ to tlie sij. in. (5) In case of suli)hateof lime waters, ncn'cr use steam of over 70 lbs. pressure. (6) In case of water holding carbonate of lime in solution, pass it through a feed- water heati'P made liot by exhaust steam or waste heat. (7) In case; of muddy waters use large feed-water cisterns or reservoirs, Oh tin- l)ottom of which the suspended earthy matters will soon form a soft deposit, when tlu; surface water can be drawn ofi' for use. Winm using hard water, save the drippings of the exhaust- j)ipe, and tin; condensation of tlio safety-valve blow-oiT, and from the cylinder, and use the water thus obtained to fill tlio boiler after blowing off. The result will be surprising in its ef. feet in loosening scale.
Slack, To burn as fuel. — A correspondent, who has practical- ly inv(;Htigated this subject extensivc-ly, says : Slack nMpiires the grate bars to be very open. I have used bars with open-
ENGINEERING.
101
Ings of li inches. The only secret in using slack with any kind of a furnace is to have the grate-bars open enougli so that the fire can be l^ept open from the under side of the grates with the poker. Some coal, of course, will go through at first ; but coarse coal and wood can be used to start with, and what falls through the grate must be raked out and put in again. The coal will soon cake so that it will not waste. Make the furnace wider than usual, in building it, with doors in the side of the front, similar to furnaces for burning sawdust. For some varieties of coal, it will be found beneficial to wet the coal before throwing it into the furnace ; this helps to run the coal together. Then put in the coal at the side doors, and let it alone till it cakes ; then with the poker roll it into the centre of the fire. It will be in large lumps and will not waste, and there will always be a good fire in the centre. Never smother it with fresh coal. A system of introducing comminuted fuel with the air required for its combustion, by means of a fan-blower, has been introduced by a Boston firm.
Specific Heat. — Table showing the number of units of heat re- quired to raise the temperature of one pound of a substance one de- gree Fahrenheit.
Copper. 0.09515
Corrosive sublimate. . . . 0.06889
Corundum 0.19762
Diamond 0.14687
Ether (liquid) 0.50342
" (vapor) 0.48100
Fusel Oil 0.56400
Galena 0.05086
Glass 0.19768
Glucinum 0.23080
Gold 0.03244
Graphite 0.20083
Hydrochloric acid 0.18450
Hydrogen 3.40900
Ice 0.47400
Iceland spar 0.20858
Indium 0.05700
Iodide of mercury 0.04197
" potassium 0.08191
" silver 0.06159
Iodine (solid) 0.05412
(liquid) 0.10822
Iridium 0.03259
Iron 0.11380
Iron pyrites 0.13001
Lead (solid) 0.03065
" (liquid) 0.04020
Lithium 0.94080
Magnesium 0.24990
Manganese 0.12170
Marble 0.20989
Mercury (liquid) 0.03332
|
Air |
0.23740 |
|
Alcohol (liquid) |
0.61500 |
|
" (vapor) |
0.45340 |
|
Aluminum |
0.21430 |
|
Ammonia (vapor) |
0.50830 |
|
Anthracite coal |
0.20100 |
|
Antimony |
0.05077 |
|
Aragonite |
0.20850 |
|
Arsenic |
0.08140 |
|
Benzine |
0.45000 |
|
Bismuth (solid) |
0.03084 |
|
(liquid) |
0.03630 |
|
Bituminous coal |
0.20085 |
|
Boron |
0.25000 |
|
Brass |
0.09391 |
|
Bromine (liquid) |
0.10700 |
|
" (gas) |
0.05550 |
|
Cadmium |
0.05669 |
|
Carbonic acid |
0.21630 |
|
" oxide |
0.24500 |
|
Chalk |
0.21485 |
|
Charcoal |
0.24150 |
|
Chloride of barium |
0.89570 |
|
" " calcium. .. . |
0.16420 |
|
"lead |
0.06641 |
|
" " magnesium |
0.19460 |
|
" " manganese. |
0.14250 |
|
Chloride of strontium. . |
0.11990 |
|
"zinc |
013618 |
|
Chlorine (gas) |
0.12100 |
|
Chromium |
0 12000 |
|
Cobalt |
0.10730 |
102
ENGINEERING.
Mercury (solid) 0.03192
Molybdenum 0.07218
Nickel 0.11080
Niobium 0.06820
Nitrate of sodium 0.27821
" silver 0.14:r)'j
Nitre 0.2:!s:,j
Nitric oxide 0.28150
Nitrogen 0.24380
Nitrous oxide 022380
Oil of turpentine (liq'd) 0.4G727 " " " (vapor). O.oOGlO
Olefiant gas 0.40400
Olive oil 0.31000
Osmium 0.03113
Oxygen 0.21750
Palladium 0.05928
Petroleum 0.46840
Phosphorus 0.18870
Platinum 0.03243
Potas.sium 0.10956
Rhodium 0.05803
Ruthenium 006110
Salt 0.17295
Sapphire 0.21737
Selenium 0.
Silica 0.
Silicon 0.
Silver 0,
Sodium 0.
Steam. ... 0.
Steel 0.
Sulphide of carbon 0.
" zinc 0
Sulphur (native) 0.
(purified) 0
(liquid) O
Sulphuric acil 0
Tantalum 0,
Tellurium 0
Thallium 0
Thorhium 0
Tin (solid) 0
" (liquid) 0
Tungsten 0
Uranium 0
Vanadium 0
Water 1.
Wood spirit 0
Zinc 0
07446 19132 ,17740 ,05701 29340 48050 11750 ,15700 .12813 ,17760 ,20259 ,23400 34300 .04840 .04737 .03355 .05800 05623 06370 .03342 06190 .08140 00000 64500 09555 B.
Staved Sukface, Safe pressure, in lbs. per square inch, for a. — Divide the scjuare of the thickness of the jdate in inches, by the square of the distance between stays, in inches, and multiply the (juotient by 16,875 for a cojjper plate, by 27,000 for a wrought-iron plate, and by 45,000 for a steel i)late
JSxanqjle. — What is the safe jiressure for a plate of wrought iron, i of an inch thick, secured by stays G inches from centre to centre ?
The quotient arising from dividing 0.0625 (the square of i) by 36, is 0.00174. Multii)lying 0.00174 by 27,000, the product is the required pressun;, about 47 lbs. per scjuare iucli. B.
Stayed Suuface, Thickness of, in inches. — Multiply the square root of the pressure, in lbs. i)er scjuare inch, by the dis- tance between centres of stays in inches, and nuiltii)ly this ])ro- ducl by 0.007698 for a (•<)i)|M'r pint.-, by 0.()()6()S5S for a wroiight- injn jjlate, l)y 0. 00171 II for a stci'l ))latc.
For a cop])ir lire box, in which the stays are 10 inches apart from centre to centre, and the pnissure f)f steam is 60 lbs. : The thickness of plate is th(! product of 7.7 Ki (the scjuare root of 60),
of an B.
wliicli is e(|iial to 0.596, or about \'i
10. and 0007698 inch
St.\y, Proper diameter for a, in inches.— Multiply tlie distance between stays, in inclies, by tlir- winare root of the ])ressure, in pounds per sipiure inch, and nniltiply this prodiu-t by 0.0206 for a c |)per stay, by ().OI7«4 lor a wrought iron stay.
Era mplc.—Wi' hat is tlie proi)er diameter loi wrought-iron
ENGHSTEERIIfG. 1 03
stays, 6 inches between centres, tlie pressure of steam being 75 i:)ounds per square inch ?
This is the in-oduct of 6, 8.66 (the square root of 75), and 0.01784 ; which is equal to 0.92697, or about |f of an inch. B.
Stats, Distance between, in inches. — Divide the thickness of tlie plate, in inclies, by the square root of the pressure, in lbs. per square iucli, and multiply the quotient by 180, if the stayed surface is copper ; by 164, if the stayed surface is wrought iron ; by 212, if the stayed surface is steel.
Suppose the fire-box of a boiler is to be made of steel plates, f of an inch thick, and the pressure of steam is to be 100 lbs. per square inch.
Divide 0.375 by 10, and multiply the quotient, 0.0375, by 212 ; which gives 7.95, say 8 inches, as the proper distance between stays. B.
Note. — The rules for stayed siirfaces and flat boiler-heads are adapted from methods explained bv Dr. Grashof in " Die Festig- keitslehre," Berlin, 1866.
VaXiVE, Safety, A simple test for determining the accuracy of. — Secure the valve-stem of the safety-valv^e to the lever with wire or string, and attach a loop to the lever, into which pass the hook of an accurate spring-balance, arranging the loop so that it is directly over the centre of the valve-stem. Then take hold of the iipper part of the spring-balance, and lift the valve slightly, noting the reading of the balance. Measure the lower diameter of the safety-valve, and find its area ; divide the read- ing of the spring-balance by the area of the valve, and the result will be the pi-essure, in pounds per square inch, at which the steam will raise the safety-valve. Suppose, for instance, that the diameter of the safety-valve is 1 inch ; its area will be about fuWo of an inch. Xow, if the tension of the spring-balance in raising the valve is 130 lbs., the pressure at which the valve will rise is the quotient arising from dividing 120 by -/tAnnj) or 153 lbs. per square inch.
A table is appended, gi^^ng the areas of valves for the ma- jority of cases that occur in practice :
Table of Areas of Valves of Different Diameters. Diameter of valve in inches. Area of valve in square inclies.
i or 0.5 13-64 or 0.19635
f or 0.625 5-16 or 0.30G80
for 0.75 7-16 or 0.44179
i or 0.875 19-32 or 0.60132
1 25-32 or 0.7854
li or 1.25 1 15-64 or 1.2272
H or 1.5 1 49-64 or 1.7671
li or 1.75 2 13-32 or 2.4053
2 3 9-64 or 3.1416
2i or 2.5 4 29-32 or 4.9087
3 7 1-16 or 7.0686
3ior3.5 9 5 8 or 9.6211
4 13 9-16 or 12.5664
• , 4| or 4.5 15 29-33 or 15.9043
104 ENGIXEERING.
Diameter of valve in inches. Area of valve in square inches.
5 19 41-64 or 19.635
5i or 5.5 28 49-64 or 23.7583
6 28 9-82 or 28.2744
B.
Vi LVE, Safety, Hints concerning the. — Some convenient ar rangi nieut, such as a cord or lever, should be fitted to a safety- valve, so that it can readily be opened by hand ; and the valve should be moved at least once a day, to keep it in good workiuj; order. A simple experiment to determine whetlier or not the valve is in truth a safety valve can readily b(=i made by everv steam-user. It will only be necessary to shut off tlie steam from the engine, or wlierever else it is used, and making up a good fire in the boiler, observe whether the pressure increases materi- ally beyond the point for which the valve is set. This experiment can be made without the slightest danger, since, if the valve will not relieve the boiler automatically, it can be opened to anv desired extent by hand. Any one can readily perceive the ini- portance of making this test, for with a good safety-valve in working order, the chances of a disastrous boiler explosion are greatly diminished. B.
Valve, Safety, Proper diameter, in inches, for a. — This de- pends upon (1) the steam-pressure to which the valve is ex- posed ; (2) the lift of the valve ; (3) tlie (luautity of steam that must be discharged in a given time, in order to prevent an in- crease of pressure. These quantities having been determined, it is necessary to calculate (1) the area of opening required in order to discharge tlie given quantity of steam ; (2) tlie diameter of a valve tliat will afford the required area of opening with the given lift.
The method of making these calculations is explained below.
A. IJie area of apening, in squ<tre inches, required, in order that a safety-valve may prevent the increase of steam-pressure beyond a given point.
(a) For stationary and marine boilers with natural draft : Take the product of (1) the area of the grate-surface in .-square feet, and (2) 2.63, and divide tliis product by the steam-pressure as shown by gauge, increased by 14.7.
{b) For stationary and marine Ijoilers with forced draft : Take the ])rodui-t of (1) the area of the grate surface in square feet, and (3) 4.08, and divide this product by the stcam-prt's.siire as shown by gaiigi;, increased l)y 14.7.
(c) For loaunotive boilers : Take the i)roduct of (1) the area of the grate-surface in stjuare feet, (2) 11.67, and divide this l)r<Kluct by the steam-pressure as shown bv gauge, increased by 14.7.
'I'o illiistriite the rules, su])pi)se that the steam-])ressuro in a locomotive jjoiler is 150 lbs. by gauge ; wliat is tlie proi)er area of opening for the esfMipt; of steam by the safety-valvo, the grate- Hurfaci^ l)eing 16 scjnare U'vX't
The product of 1(1 and 11. ((7 is 186.72, and the quotient arising from dividing' thi.s In tin- sum of 150 and 14.7, or 161.7, is about llVo square ini'hes, whi(;h is the recjuired area of opening.
ENGINEERING.
105
Divide this (2) tlie sine of
B. The diameter of valve, in inches, required, to afford the neces- sary area of opening loith the given lift.
(rt) When the lift of the valve is equal to or less than the depth of the seat : Diminish the required area of opening by the product of (1) the square of the lift, in inches ; (2) the square of the sine of the angle of bevel of the valve ; (oj the cosine of the angle of bevel of the valve, and (4) 3.1416. difference by the product of (1) the lilt in inches the angle of bevel of the valve, and (3) 3.1416.
(6) When the lift of the valve is greater than the depth of the seat : Diminish the required area of opening by the product of (1) the square of the depth of seat, in inches ; (2) the square of the sine of the angle of bevel of the valve ; (3) the cosine of tlie angle of bevel of the valve, and (4)3.1416. Divide this difference by 3.1416 times the sum of (1) the depth of seat in inches, multiplied by the sine of the angle of bevel of the valve, and (2) the difference between the lift and the depth of seat, in inches.
A table of sines and cosines of angles from 20° to 50° will be found below, and an example is appended in illustration of the rules.
|
Angle. |
Sine. |
Cosine. |
Angle. |
Sine. |
Cosine. |
|
20° |
.342 |
.940 |
36° |
.588 |
.809 |
|
21° |
.358 |
.934 |
37° |
.602 |
.799 |
|
22° |
.375 |
.927 |
38° |
.616 |
.788 |
|
23° |
.391 |
.921 |
39° |
.629 |
.777 |
|
24° |
.407 |
.914 |
40° |
.643 |
.766 |
|
25° |
.423 |
.906 |
41° |
.656 |
.755 |
|
26° |
.438 |
.899 |
42° |
.669 |
.743 |
|
27° |
.454 |
.891 |
43° |
.682 |
.731 |
|
28° |
.469 |
.883 |
44° |
.695 |
.719 |
|
29° |
.485 |
.875 |
45° |
.707 |
.707 |
|
30° |
.500 |
.866 |
46° |
.719 |
.695 |
|
31° |
.515 |
.857 |
47° |
.731 |
.682 |
|
32° |
.530 |
.848 |
48° |
.743 |
.669 |
|
33° |
.545 |
.839 |
49° |
.755 |
.656 |
|
34° |
.559 |
.829 |
50° |
.766 |
.643 |
|
35° |
.574 |
.819 |
Example. — A safety-valve has a bevel of 33°, a depth of seat of i inch, and is required to give an area of opening of 2 inches, with a lift of \ inch. What should be its diameter?
Square of depth of seat 0.0625
Square of sine of 33' 0.297
Product 0.019
Cosine of 33= 0.839
Product •- 0.016
106 BNGINEEUING.
Product (broujrlit forward) 0.016
Multiply by i5.1410'
Product 0.05
Area of opening 2.00 in.
Subtract 0.05
DifEerence is 1.95
Depth of seat 0.25
Sine of 33° 0.545
Their product 0.136
Multiply by 3.141C
Product 0.427
Lift 0.50
Subtract depth of seat 0.25
The difierence is « . . .0.25
Multiply by 3.1416
And the product is 0.785
Add 0.427
1.212 Now 1.95 divided by 1.212 gives the diameter of valve, 1.61 inches, nearly. B.
V.\LVK, Safety, Proportions of parts of. — 1st. To find the pres- sure per square inch (it which (Kjimn caloe mill open. Measure the following distances horizontally from the fulcrum to (1) the centre of the valve-stem ; (2) the centre of tlie weight ; (3) the centre of gravity of the lever, or the point on whicli it will bal- ance if jilaced upon a knife-edge. Measure the diameter of the valve, and determine its area, eitlier from a table or by multiply, ing the square of tlm diameter by 0.7H54. Find the weight of
(1) the valve; (2) the lever; (3) the ball. Multiply (1) the weight of the ball by its liorizontal distance from the fulcrum ;
(2) the weiglit of the lever by its horizontal distance from the fulcrum ; (3) the weight of th(i valve by its horizontal distance from \\\v. ful(Tum ; (4) tlu; area of the valve by its horizontal distance from the fulcrum. Add togetlu'r thelirst three proilucts and divide the sum by the fourth product.
Hxdinplc. — A givtMi safety-valve has a weight of 50 lbs. 21 inches from th(! fulcrum, th(! lever weighs (i lbs., and its (•eiitr(^ of irravity is 15 inches from the fulcrum ; the weight of i\w valv(^ is 2 lbs., and its centre is 4 inches from the fulcrum. The dia- met(!r of tlie valve is 2 inches. At what pressure will the valve b(!gin to riseV
Scjuarc! of diameter 4
Multiply by 0.7H5I
Area of valve in stpiare inclies 3.1416
(1)50 times 24 is 1200 ; (2) 6 times 15 is 90; (3) 2 times 4 is
ENGINEERIXG. 107
8 ; (4) 4 times 3.1416 is 12.5G64. The sum of (1), (2), and (3) is 1298, which divided by 12.5604 (the fourth product) is 103.03, the pressure in lbs. per square inch at which the valve will open.
2d. I'd find where to place the weight on a safety-valce so that it shall open at a given pressure of steam. Multiply (1) the weight of the lever by the horizontal distance of its centre of gravity from the fulcrum ; (2) the weight of the valve by its horizontal distance from the fulcrum ; (3) the area of the valve by the pressure of steam in lbs. per square inch, and by the horizontal distance of the valve fi'om the fulcrum. Add together the first two products, subtract their sum from the third product, and di- vide the difference by the weight of the ball.
Example. — The ball of a safety-valve weighs 100 lbs., the lever weighs 10 lbs., the valve weighs 2 lbs., and has a diameter of 3 inches. The distance of the centre of gravity of the lever from the fulcrum is 25 inches, and the distance of the centre of the valve from the fulcrum is 5 inches. How far from the ful- crum must the valve be placed, in order that the lever may open at a pressure of 100 lbs.?
Area of valve, 7.07 square inches.
(1) 10 times 25 is 250 ; (2) 2 times 5 is 10 ; (3) the product of 7.07, 100, and 5, is 3535. Adding togetlier products (1) and (2), we have as their sum 260 ; subtracting this from 3535, the third product, we have 3275. Dividing this difference by 100, the weight of the ball, we have 32.75, or 32f inches as the distance from fulcrum to ball.
To find ichat diameter a safety-valve must have, the other ixirts be- ing known to open at a given steam pres.szire. Multiply (1) the weight of the ball by its horizontal distance from the fulcrum; (2) the weight of the lever by the horizontal distance of its centre of gravity from the fulcrum ; (3) the weight of the valve by the horizontal distance of its centre from the fulcrum ; (4) the pres- svtre of steam in pounds per square inch by the horizontal dis- tance of the valve from the fulcrum, and by the number 0.7854. Add together the first three products, divide their sum by the fourth product, and take the square root of the quotient.
Example. — Weight of ball, 00 lbs. ; lever, 7 lbs. ; valve, 3 lbs. Distances from fulcrum : ball, 30 inches ; centre of gravity of lever, 16 inches ; centre of valve, 3 inches. Pressure of steam, 70 lbs. per square inch. What should be the diameter of the valve ?
(1) The product of 60 and 30 is 1800 ; (2) the product of 7 and 16 is 112 ; (3) the product of 3 and 3 is 9 ; (4) the product of 70, 3, and 0.7854 is 164.934. The sum of the first three products, 1800, 112, and 9, is 1921. Dividing this sum by 164.934 (the fourth product), we have 11.647 inches. The square root of this number is 3.41 -i- inches, which by the rule is the required dia- meter of the valve. B.
Valve, To find the angle of bevel of a. — This is the angle of inclination /c a, or e d h, to a vertical line. Make the following measurements : (1) greatest diameter, g h, of valve, in inches ; (2) least diameter, a h, of valve, in inches ; (3) depth, a k, of valve, in inches. Divide the difference of the greatest and least
108
ENGINEEKING.
diameters by tlie depth of seat. Find the angle whose tangent is nearest this quotient, in the accompanying table of tangents.
C d
Table of Tangents from 20° to 50°.
Example. — The greatest and least diameter of a valve are 4 G-10 and 4 inches, respectively, and the depth is \ inrli. Wliat is the bevel 'i
(Jreati'st diameter 4.(i
Least diameter 4.
2)0. (J
0.5)0.3
Tangent of angl<' of incliimtion O.G
From tin- tablf, it appears tliiit tlic angii! corresponding to this is nearly lil . 1^-
ValvK, To liiid tlif arrii of (>|iciiiiii,', in S(|iiiur iiiciii'.s, of a, due to a given lift. — ('/) VViicn ilir lift <>f tin' vulve is equal
ENGINEERING. 109
or to less than the depth of seat : Find the product of (1) the diameter of the valve, in inches ; (3) the lift, in inches ; (3) the sine of the angle of bevel of the valve, and (4) 3.1416. Add this to the product of (1) the square of the lift, in inches ; (2) the square of the sine of angle of bevel of the valve ; (3) the cosine of the angle of bevel of the valve, and (4) 3.1416.
(6) When the lift of the valve is greater than the depth of seat : Find the product of (1) the diameter of the valve, in inches ; (2) the depth of seat, in inches ; (3) the sine of the angle of bevel of the valve, and (4) 3.1416. Find the product of (1) the square of the depth of seat, in inches ; (2) the square of the sine of the angle of bevel of valve ; (3) the cosine of the angle of bevel of valve, and (4) 3.1416. Find the product of (1) the diameter of the valve, in inches ; (2) the difference between the lift and the depth of seat, in inches, and (3) 3.1416. Take the sum of these three products.
Example. — The diameter of a valve is 4 inches, the bevel is 35°, and the depth of seat ^ of an inch. What is the area of open- ing for a lift of f of an inch ?
The product of 4, 0.25, 0.574 (the sine of 35=), and 31416 is 1.8.
The product of the square of 0.25, the square of 0.574, 0.819, (the cosine of 35°), and 3.1416 is 1.85.
The product of 4, 0.125 (the diflference between the lift and depth of seat), and 3.1416 is 1.57.
The sum of 1.8, 1.85, aad 1.57 is 3.42 square inches, the area of opening required, B.
BELTS, PULLEYS, AND SHAFTING.
Belt-Holes, Laying out, through floors.— If a belt is to be carried from a pulley on an overhead shaft to one on any floor above, tlie distance from centre of lower shaft to ceiling— under side of floor — should be measured and noted ; then the thickness of floor ; next the distance between top of floor and centre of upper shaft. If one pulley or shaft is directly over the other, the size of pulleys and width of belt being known, you have all the data necessary if you measure the distance of one shaft from the wall of building, which is done by dropping a plummet from centre of shaft or diameter of pulley, and measuring to the wall from that point. From these data, whether the two shafts are in the same vertical plane, whether the diameters of the pul- leys are equal, and whether the belt is to be carried through one, two, three, or even four floors or not, the intelligent mechanic can lay out a diagram that will enable him to cut his belt-holes ac- curately. The diagram may be laid out full-size on a swept floor, or, on a reduced scale, on a board or sheet of paper. ]SIea- sures thus made can easily be transferred to the floor through which the holes are to be made.
110 ENGINEERING.
BELT-LACixa, Eel-pkin. — A mill-owner says : " Eel-skins make the best possible strings for lacing belts. One lace will outlast any belt, and will stand wear and liard usage wliere hooks or any other fastenings fail. Our mill being on the bank of the river, we keep a net set for eels, which, when wanted, are taken out in the morning and skinned, and the skins are stuck on a smooth board. When dry, we cut them in two strings, making the eel-skin, in three hours from the time the fish is taken from the water, travel in a belt."
Belt-Lacings, Holes for. — The strain on belts is always in the direction of their length, and therefore holes cut for the reception of lacing slioiild be oval (the long diameter in line with the belt). In ])utting or meeting belts, the crossings of the lacings should be on the outside.
Belt passinc; over t'wo Pui^leys, To find the length of a. — Measure the distance between the centres of the pulleys, the diameters of the pulleys, and the thickness of the belt. Add the thickness of the belt to the diameter of a pulley, and this gives the effective diameter. Half this is the effective radius, and it is to be noted that the effective radius, or tlu' effective diameter, of a pulley should generally be used in all calculations relating to belts and pulleys. In making such calculations, care must be taken, also, to liave all the dimensions in the same unit, feet or inches. In general, it is well to reduce all dimensions to feet.
To illustrate the ])receding remarks, suppose that the diame- ter of a pulley is 10 inches, and that the thickness of the belt passing over it is f of an incli. What is the effective radius, in feet? Ati.s. The effective diameter is lOg inches ; hence the effec- tive radius is o.^*,; inches. 5 inches is 0.417 ft. ,'',, of an inch is 0.010 ft. Hence 5,=^,; inches is 0.433 ft.
There are two cases to be considered, one in which the belt ia crossed, and the other in which it is open.
To find the length of a cronxed belt pnssiDf/ orrr tiro judlci/s :
(1) Divide the sum of the radii of the two pulleys by the dis- tance between their centres, and lind from the table of factors the factor corres|)onding to this quotient.
(2) Multii)ly the factor so found by the sum of the radii.
(3) Multiply the sum of the radii by the number 3.141G.
(4) Siil)tiart tins sijuare of the sum of the radii from tlu; 8(juare of the distance Ix-twcen centres, and take the s(|uare root of the remainder. Multiply tlie (juantity so obtaiiu'd liy 2.
(5) Take tlie sum of the quantities obtained by (2), (3), and (4). Krampfr. — Tlu; radius of one pulley is 42 inches, of the other
3(» ; tlie distance between centres of pulleys is 12 feet, and the tliickness of tlie lielt is \ of an imli ; rei|iiiir(l, the length of tlu^ belt.
'I'iie efff'ctive radii an; 3.51 fi^rt and 3.01 feet.
(1) Sum of radii, 0.520. Distaiwe betwi-en centn^s, 12. Quo- tient of first (|uantity divided by second, 0.51. Factor in talih: I'orrespnnding lo this quotient, 1.141.
(2) i.ni innitii)iied hy i\.r,':>, 7.430 t .
(3) 0.541 multipli.-d by 3. 1.41(..20.4H3 + .
ENGINEERING.
Ill
(4) Square of distance between centres 144.
Square of sum of radii. . 42.51
Difference 101.49
Square root of difference, 10.074 + . 10.074 multiplied by 2, 30.148.
^ (5) Sum of 7.439, 20.483. and 20.148, 48.07 feet, or 48 feet and U of an inch, length of belt required.
Table of Factors for Determining the Length of Belts.
|
Quotient. ! |
Factor. ' |
Quotient. |
Factor. |
|
0.01 |
0.020 |
0.35 |
0.716 |
|
0.02 |
0.040 1 |
0.36 |
0.737 |
|
0.03 |
0.060 i |
0.37 |
0.758 |
|
0.04 |
0.080 ' |
0.38 |
0.780 |
|
0.05 |
0.100 |
0.39 |
0.802 |
|
0.06 |
0.120 |
0.40 |
0.823 |
|
0.07 |
0.140 |
0.41 |
0.845 |
|
0.08 |
0.161 |
0.42 |
0.867 |
|
0.09 |
0 180 |
0.43 |
0.890 |
|
0.10 |
0.201 |
0.44 |
0.912 |
|
0.11 |
0.220 |
0.45 |
0.934 |
|
0.12 |
0.241 |
! 0.46 |
0.956 |
|
0.13 |
0.261 |
0.47 |
0.979 |
|
0.14 |
0.281 |
0.48 |
1.002 |
|
0.15 |
0.301 |
0.49 |
1.025 |
|
0.16 |
0 322 |
i 0.50 |
1047 |
|
0.17 |
0.342 |
; 0.51 |
1.070 |
|
0.18 |
0.362 |
0.52 |
1.094 |
|
0.19 |
0.383 |
0.53 |
1.118 |
|
0.20 |
0.403 |
0.54 |
1.141 |
|
0.21 |
0.424 |
0.55 |
1.165 |
|
0.22 |
0.444 |
0.56 |
1.189 |
|
0.23 |
0.464 |
i 0.57 |
1.214 |
|
0.24 |
0.485 |
1 0.58 |
1.238 |
|
0.25 |
0.506 |
' 0.59 |
1.262 |
|
0.26 |
0.527 |
0.60 |
1.287 |
|
0.27 |
0.547 |
0.61 |
1.312 |
|
0.28 |
0.568 |
0.62 |
1.338 |
|
0.29 |
0.589 |
. 0.63 |
1.364 |
|
0.30 |
0.610 |
0.64 |
1.389 |
|
0.31 |
0.631 |
0.65 |
1.415 |
|
0.32 |
0.652 |
' 0.66 |
1.443 |
|
0.33 |
0.673 |
i 0.67 |
1.469 |
|
0.34 |
0.694 |
0.68 |
1.496 |
|
Quotient. |
Factor. |
|
0.69 |
1.533 |
|
0.70 |
1.551 |
|
0.71 |
1.580 |
|
0.72 |
1.608 |
|
0.78 |
1.637 |
|
0.74 |
1.666 |
|
0.75 |
1.696 |
|
0.76 |
1.727 |
|
0.77 |
1.758 |
|
0.78 |
1.790 |
|
0.79 |
1.822 |
|
0.80 |
1.855 |
|
! 0.81 |
1.888 |
|
; 0.82 |
1.923 |
|
' 0.83 |
1.958 |
|
I 0.84 |
1.995 |
|
0.85 |
2.033 |
|
0.86 |
2.071 |
|
0.87 |
2.111 |
|
0.88 |
2.152 |
|
0.89 |
2.195 |
|
0.90 |
2.240 |
|
0.91 |
3.387 |
|
0.92 |
2.336 |
|
0.93 |
3.389 |
|
0.94 |
2.446 |
|
0.95 |
2.507 |
|
0.96 |
2.574 |
|
0.97 |
2.651 |
|
0.98 |
2.743 |
|
0.99 |
2.859 |
|
1.00 |
3.143 - |
To find the length of an open belt passing orer tiro pullei/s : (1) Divide the difference of the radii by the distance between
112 ENGINEERING.
centres, and find fro-.u the table of factors the factor correspond- iiig to this quotient.
{2) Multiply the factor so found by the difference of the radii.
(3) Multiply the sum of the radii by the number 3.1410.
(4) Subtract the square of the difference of the radii from the square of the distance between centres, and take the square root of the remainder. Multiply the quantity so (obtained by 2.
(5) Take the sum of the quantities obtained by (3), (3), and (4). It will be observed that these rules require only simple arith- metical operations.
Example. — Given, diameter of driving-wheel, 36 inches; of driven wheel, 9 inches ; distance between centres, 5 feet ; thick- ness of belt, \ of an inch ; what is the length of tlie bellV
Effective radii, 1.505 and 0.3S0 feet. (1) Difference of radii, 1.125. Distance between centres, 5. Quotient, 0.33. Factor in table corresponding to this quotient, 0.404. (3) 0.404 multiplied bv 1.135, 0.533. (3) Sum of radii, 1.885. 1.885 multiplied by 3.1416, 5.933.
(4) Square of distance between centres 35.
Square of difference of radii 1.366
Difference 33.734
Square root of difference, 4.873. 4.873 multiplied by 3, 9.744. (5) Sum of 0.533, 5.933, and 9.744, 16.188 feet, or 16 feet 2^ inches, length of belt. B.
Belts, Power transmitted by leatlier. — By the aid of the ac- companying tables, now ])ubli8h(;d for the first time, it will be easy for any one to ascertain the amount of power that can be safely transmitted by good leather belts under ordinary circum- stances. It is scarcely necessary to add that the power trans- mitted by a belt in any special case can only be ascertained by experiment. All that can b(! done by the most elaborate rules is to show what power ought io be transmitted if a belt is properly arranged. The tables and accompanying rules will be useful, therefore, in calculations of the widih of belt retjuired to do a definite amount of work under given circumstanc^^s. With these preliminary explanations, the use of the tables will be illustrated.
I. Other tMiifjs heiiuj cfiuid, the power trnnstnitted hi/ a belt de- pends upon the arc of raittwt and the xpeed <>f the belt.
II. To find the arc of contact between a belt and a pulley, by the aid, of the neeonipanyliKj table.
Firnt \fethod. — .Measure the liMigth of tin- portion of th(^ cir- ciiiiifcri'iicc of tin; ])ii]lcy that is in contact with the belt, and tbe diamclcr of the pulh^y. Divide; the first measurement by the radius of the ])ulley, which gives the length of the arc of contact for a circle wliose radius is I. Mud tlic nuinbi-r nearest to this in the column of t!ie talile liiMdrd " i>c'iii:tli of arc for a radius of 1," and till- rc(juirrd imglc will i)r found in tlii; same liori- zo.ital lint' of tin; next column, to the UdV, Invaded " Arc of con- tact. "
ENGINEERING.
113
lule for Finding the Are of Contact of a Belt loith a Pulley.
|
El |
Both pulleys, crossed belt, and large pulley, open belt. |
Small pulley, open belt. |
||
|
< z O |
Arc of contact. |
Length of arc for a radius of 1. |
Arc of contact. |
Length of arc for a radius of 1. |
|
0.00 |
180° |
3.142 |
180° |
3.142 |
|
.01 |
181" |
3.162 |
179° |
3.122 |
|
.02 |
182° |
3.182 |
178° |
3.102 |
|
.03 |
183° |
3.202 |
177° |
3.082 |
|
.04 |
185° |
3.222 |
175° |
3.062 |
|
.05 |
186° |
3.242 |
174° |
3.042 |
|
.06 |
187° |
3.262 |
173° |
3.022 |
|
.07 |
188° |
3.282 |
172° |
3.002 |
|
.08 |
189° |
3.303 |
171° |
2.981 |
|
.09 |
190° |
3.322 |
170° |
2.962 |
|
.10 |
192° |
3.343 |
168° |
2.941 |
|
.11 |
193° |
3.362 |
167° |
2.922 |
|
.12 |
194° |
3.383 |
166° |
2.901 |
|
.13 |
195° |
3.403 |
165° |
2.881 |
|
.14 |
196° |
3.423 |
164° |
2.861 |
|
.15 |
197° |
3.443 |
163° |
2.841 |
|
.16 |
198° |
3.464 |
162° |
2.820 |
|
.17 |
200° |
3.484 |
160° |
2.800 |
|
.18 |
201° |
3.504 |
159° |
2.780 |
|
.19 |
202° |
3.525 |
158° |
2.759 |
|
.20 |
203° |
3.545 |
157° |
2.739 |
|
.21 |
204° |
3.566 |
156° |
2.718 |
|
.22 |
205° |
3.586 |
155° |
2.698 |
|
.23 |
207° |
3.606 |
153° |
2.678 |
|
.24 |
208° |
3.627 |
152° |
2.657 |
|
.25 |
209° |
3.648 |
151° |
2.636 |
|
.26 |
210° |
3.669 |
150° |
2.615 |
|
.27 |
211° |
3.689 |
149° |
2.595 |
|
.28 |
213° |
3.710 |
147° |
2.574 |
|
.29 |
214° |
3.731 |
146° |
2.553 |
|
.30 |
215° |
3.752 |
145° |
2.532 |
|
.31 |
216° |
3.773 |
144° |
2.511 |
|
.32 |
217° |
3.794 |
143° |
2.490 |
|
.33 |
219° |
3.S15 |
141° |
2.469 |
|
.34 |
220° |
3.836 |
140° |
2.448 |
|
.35 |
221° |
3.858 |
139° |
2.426 |
|
.36 |
222° |
3.879 |
138° |
2.405 |
|
.37 |
223° |
3.900 |
137° |
2.384 |
|
.38 |
225° |
3.922 |
135° |
2.362 |
|
.39 |
226° |
3.944 |
134° |
2.340 |
|
.40 |
227° |
3.965 |
133° |
2.319 |
|
.41 |
228° |
3.987 |
132° |
2.297 |
|
.43 |
230° |
4.009 |
130° |
2.275 |
|
.43 |
231° |
4.032 |
129° |
2.252 |
|
.44 |
232° |
4.054 |
128° |
2.230 |
|
.45 |
234° |
4.076 |
126° |
2.208 |
|
.46 |
235° |
4.098 |
125° |
2.186 |
|
.47 |
2:^6° |
4.121 |
124° |
2.163 |
|
.48 |
237° |
4.144 |
12:}° |
2.140 |
|
.49 |
239° |
4 167 |
121° |
2.117 |
|
.50 |
240° |
4.189 |
120° |
2.095 |
114
ENGINEEKING.
Table for Finding the Arc of Contact of a Belt tcitJi a Pulley.
(Continued.)
|
^ |
Both pulleys, crossed belt, and large pulley, open belt. |
Small pullej% open belt. |
||
|
1 CONSTAK |
Arc of contact. |
Length of arc for a radius of 1 . |
Arc of contact. |
Length of arc tt a radius of 1. |
|
.51 |
241° |
4.212 |
119° |
2.072 |
|
.52 |
243° |
4.236 |
117° |
2.048 |
|
.53 |
244° |
4.260 |
116° |
2.0^ |
|
.54 |
245° |
4.283 |
115° |
2.001 |
|
.55 |
247° |
4.307 |
113° |
1.977 |
|
.56 |
248° |
4.331 |
112° |
1.953 |
|
.57 |
250° |
4.356 |
110° |
1.928 |
|
.58 |
251° |
4.380 |
109° |
1.904 |
|
.59 |
252° |
4.404 |
108° |
1.880 |
|
.60 |
254° |
4.429 |
106° |
1.855 |
|
.61 |
255° |
4.454 |
105° |
1.830 |
|
.62 |
257° |
4.480 |
103° |
1.804 |
|
.63 |
258° |
4.506 |
102° |
1.778 |
|
.64 |
260° |
4.531 |
100° |
1.753 |
|
.65 |
261° |
4.557 |
99° |
1.727 |
|
.66 |
263° |
4.585 |
97° |
1.699 |
|
.67 |
264° |
4.611 |
%° |
1.673 |
|
.68 |
266° |
4.638 |
94° |
l.WO |
|
.69 |
267° |
4. 065 |
93° |
1.G19 |
|
.70 |
269° |
4.693 |
91° |
1.5'Jl |
|
.71 |
271° |
4.722 |
89° |
1.562 |
|
.72 |
273° |
4. 750 |
88° |
l.o:i4 |
|
.73 |
27'1° |
4.779 |
86° |
1..505 |
|
.74 |
275° |
4.808 |
85° |
1.476 |
|
.75 |
277° |
4.8:^8 |
83° |
1.446 |
|
.76 |
270° |
4.86«J |
81° |
1.415 |
|
.77 |
281° |
4.900 |
79° |
1.384 |
|
.78 |
283° |
4.932 |
77° |
1.3.->2 |
|
.79 |
284° |
4.9&1 |
76° |
1.320 |
|
.80 |
286° |
4.9!>7 |
74° |
1.387 |
|
.81 |
288° |
B.CCiO |
72° |
1.2.54 |
|
.82 |
290° |
5.(Hi5 |
70° |
1.319 |
|
83 |
292° |
5.KX) |
68° |
I.IM |
|
.84 |
294° |
5.137 |
6<i° |
1.147 |
|
.85 |
296° |
5.174 |
M° |
1.110 |
|
.86 |
299° |
5.213 |
61° |
1 (171 |
|
.87 |
801O |
5.2.'>3 |
59° |
1 ();il |
|
.88 |
808° |
6.294 |
57° |
(1 '.190 |
|
.89 |
306° |
5..S:}7 |
54° |
0.9-17 |
|
.90 |
308° |
5.382 |
.'J2° |
0.902 |
|
91 |
311° |
5.429 |
49° |
0.8.-)5 |
|
.92 |
314° |
5.478 |
46° |
0.8(16 |
|
.98 |
817° |
5.581 |
48° |
o.7.'>:i |
|
.94 |
820° |
5.588 |
40° |
0.(i9C> |
|
.95 |
824° |
5.(M9 |
:«i° |
(t.(kJ5 |
|
.96 |
888° |
5.716 |
32° |
()..")C)8 |
|
.97 |
832° |
5.793 |
28° |
0.491 |
|
.98 |
837° |
5.885 |
iSl" |
0:VM< |
|
.99 |
844° |
li.OOl |
1(1" |
(l.-JKJ |
|
1.00 |
aio° |
6.284 |
(I" |
0 (KM) |
ENGLXEERIXG. 115
Example. — Suppose the length of tlie circumference of a pul- ley in contact with a belt is 8A feet, and the diameter of the pulley is 4 feet. The quotient arising from dividing 8^ by 2 (the radius of the pulley) is 4.25, and the number in the table nearest to this is 4.26, showing that the required arc of contact is about 244°.
[It is to be noted that, in calculations of this kind, the effective radius of the pulley should be used (see page 110), and all dimen- sions must be referred to the same unit of measurement.]
Second Method. — Measure the effective diameters of both pul- leys, and the distance between their centres. There are two cases to be considered :
(a) To find the arc of contact for a crossed belt.
Divide the sum of the radii of the two pulleys by the distance tween their centres ; find in the column of constants the nearest number to the quotient, and pick out the corresponding angle.
Example. — Diameter of driven pulley, 20 inches ; of driving pulley, 24 ; distance between centres, 8 feet. What is the arc of contact on each pulley of a crossed belt passing over them ? Sum of radii, 1.8333 feet. 1.8333 divided by 8 is 0.23, nearly. From the table, it appears that the angle required is 207\
(b) To find the arc of contact for an open belt.
Divide the difference of the radii of the two pulleys by the distance between their centres, and find the angles corresponding to the constant nearest to the quotient, in the table.
Example. — In the case of an open belt passing over two pul- leys, the following dimensions are given : Diameter of driving pulley is 5.25 feet; diameter of driven pulley is 3.5 feet; dis- tance between centres is 9 feet. The difference of radii (0.875) di- vided by 9 is 0.097-]-. Neare.st constant in table, 0.1, correspond- ing to an angle of contact of 192' on the driving, and 168° on the driven pulley.
[These rules are founded on the assumption that the belt is drawn perfectly tight between the pulleys. Where there is much deviation from this, in practice, it is better to emjjloy the first method.]
III. To find the speed of a helt, infect, per minute.
Multiply the diameter of either imlley, in feet, by 3.1416 times the number of revolutions that it makes per minute.
Example.— \ belt passes over a pulley that is 3 feet in diame- ter, and makes 200 revolutions a minute". The speed of the belt is the product of 3, 3.1416, and 200, or about 1885 feet per minute.
ly. To find the potcer that can he safely transmitted by a good leather belt of given width, passing over smooth iron jniUeys, and running at a given speed, the arc of contact beinq als', given.
This IS determined by means of the second table Find the horse-power for a belt one inch in width, for the nearest arc of contact in the table, and the nearest speed of belt, and multinlv this by the width of the belt. If the belt is open, and the pul- leys have different diameters, take the angle of contact made by the belt with the smaller pulley.
116
ENGINEERING.
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ENGINEERING.
119
Example. — What horse-power can be transmitted by a leather belt 10 inches wide, making an angle of contact of 80' with the smaller of the two pulleys over which it passes, and having a speed of 2400 feet per minute? Ans. — Horse-power for a belt 1 inch wide and 2000 feet speed is 1.802 ; horse-power for a belt 1 inch wide and 400 feet speed is 0.3G0 ; therefore, by addition, horse- power of 1 inch belt for 2400 feet speed is 2.162;" and for 10 horse- power, 10 times 2.162, or 21.62.
V. 2'f find the icidth of belt necessary to transmit a ffiven, amount of poicer for a given are of contact and given speed in feet per minute.
Find the power transmitted by a belt 1 inch wide, and divide the given power by this amount.
Example. — An open belt passes over two pulleys having dia- meters of 4 and 6 feet respectively, and the former makes 300 revolutions a minute. The distance between the centres of the pulleys is 15 feet. What should be the width of a belt to trans- mit 50 horse-power under these circumstances ? Speed of belt in feet per minute, 3770 ; arc of contact of belt Avith smaller pulley, 172^ ; horse-iX)wer transmitted by a belt 1 inch wide, under conditions in table nearest to those determined above {i.e. , for arc of contact of 170", and speed of 3800), 5.488. Required width of belt, 50 divided by 5.488, or a little over 9 inches.
VI. In the use of a leather belt, it is best to run it with the grain side next to the pulleys, or in exactly the opposite way from that in which the hide was worn by the animal that was the original proprietor of the leather.
VII. Lace-leather is better than hooks for fastening the ends of a belt togetlier ; and a still better method, after a belt has be- come sufficiently stretched by use, is to rivet the ends together with long laps. In lacing a belt of any considerable size, make two rows of holes in each belt end, and" put in double lacing.
VIII. A belt that is made of good material, and is of ample size, will last for many years, if kept clean, and prevented from becoming dry and hard by the use of neat's-foot oil. It is poor economy to buy a belt whose chief recommendation is its small first cost. It is also a bad plan to use a belt that is just suflicient to transmit the power when Very tightly strained. B.
CORNER-TURNED BELT.
Belts, Corner-turned, Device for.— The two shafts placed at right angles, as shown in the engraving, carry the belt from A or
120
ENGINEERING.
B, passing around two flanged pulleys or guides, C, turning loose- ly on a fixed upright shaft, and sustained in position bj^ a collar under the hub of each. It is possible to run pulleys by this de- vice which not only have varying diameters, but the shafts of which are on different levels ; but the results are not so good, owing to unequal strain on the belt. It is better to confine this method to shafts on the same level, and to pulleys of equal dia- meter, and the useful limit of angle of shafts is that of 45°, or less. A greater or more obtuse angle is better run by means of guides on two uprights.
Belts, Coupling. — In Fig. 1, A, B, C, and D are pieces of No. 16 sheet-iron, riveted to the ends of the belt ; E E are hooks, shown in the natural size in Fig. 2 , riveted to B. After the belt
■lUI'I.lNC r.Kl.TS.
is laid over tin; pulleys, tin; hooks, F and (J, of the lever, sliown in Fig. 8, are placed in the holes at C and D. Now the two ends of the belt are drawn together by the lever, H, and the hooks. E, are i)ut in their places at A. Then the lever is taken out, leaving the joint finished. By this nietliod, two men can set and couple a belt in the least possible time, obtaining an eff«;ctual joint, which will never allow the belt to run out of true, or to re- verse.
Belts, Increasing the conveying fore*- of. — Adding to the width of a l)e.lt and of the faces of the jiiilleys increases immensely the ])ower of conveying force. A wide belt is always better than a narrow one, strained to its utmost ca|)acity.
Bklts, Mending. — Lay llii' two I'nds of the l^(;lt exactly even, witli tlie insi(h'S together, and piincli one straiglit row of holes across tlie end, driving the piincli through both i)leceH so that the
ENGINEERING. 121
holes may correspond. Now take your lace, pointed at both ends, and pass the points in opposite directions through the first hole, still keeping the two ends of the belt together as when punched, and draw the loop tight, observing to keep the ends of equal length. Pass the points through the second hole, and so proceed to the last ; then tie the ends over the edge of the belt, and the job is done. A belt can thus be mended in half the time and with half the length of lacing required in the usual way ; and wlien the belt is subjected to heavy strains or slipping, it will wear ten times as long, as the lace never touches the pulley- faces. Of course the plan is not applicable when both sides of a belt run over pulleys, nor when the projecting ends would strike any thing in their track.
Belts, Oiling. — The best mode of oiling a belt is to take it from the pulleys, and immerse it in a warm solution of tallow and oil ; after allowing it to remain a few moments, the belt should be immersed in water heated to 100° Fahr., and instantly removed. This will drive the oil and tallow all in, and at the same time properly temper the leather.
Belts, Rubber, To prevent, slipping on pulleys. — Chalk the pulley when slipping occurs. The presumption is, however, that the belt is either too narrow or too loose.
Belts, Splicing large. — Cut your belt perfectly square on the ends and to the proper length ; then cut a piece of belt of the same width and thickness, about 3 feet long. Bring the ends of the belt together, and put the short piece on the back of the joint, or outside, and bolt the belt and piece together with what are known as elevator- bolts, used for fastening the buckets to elevator-bands_. The tools required are a brace and bit to bore the holes, and a small pair of blacksmith's tongs to tighten up the nuts with.
Belts, Testing leather for. — A. cutting of the material about 0.03 of an inch in thickness is placed in strong vinegar. If the leather has been thoroughly acted upon by the tanning, and is lience of good quality, it will remain, for months even, immersed without alteration, simply becoming a little darker in color. But, on the contrary, if not well impregnated by the tannin, the fibres will quickly swell, and, after a short period, become trans- formed into a gelatinous mass.
Belts, To lay out quarter-twist. — To make holes through floors for the belts, lay out on a floor with chalk-line and train two views of the pulley, or by scale on paper as shown in the an- nexed diagram. B is the belt running in the direction of the arrow on the lower pulley, and C is the belt running in the opposite direction. Therefore, drop a plumb-line, representing the perpendiculars, B and C, and draw the diagonals governed by the diameters of the pulleys, marking the distances a b and c d on the floor. Now, drop a plumb-line from each side of the cen- tre of face of upper pulley to the floor, and from one point, c,
122 EXGIXEERIXG.
thus found, lay off the distance a h, in a line parallel with the upper shaft, and from the point n in the distance, f d, parallel
T.AYIMi OIT l^lAltTKI!-TWI>T BEIT-" Tllltorull FI.OOIIS.
with the lower shaft. ThoHc points are tin- places at which the hok'H should be cut.
FuKTioN ANi") LrnurcANTs. — Whenever one surface moves uj)on anotlirr, tlic roii^h and iiri)jccfinjf ])oints of tlic f wo sur- face's (wliich always exist, even in tin- siiioofhcst surfaces) op- pose resistiuice to the motion, and tliis resistance is called fric- tion.
ENGINEERING. " 123
The coefficient of friction is a quantity expressing the ratio of the friction to the pressure. For instance, if the resistance to moving one piece of metal on another is one fifth of the weight of the moving body, the coefficient of friction in this case is one fiftli, or 0.2. Hence, knowing the coefficient of friction, in any given instance, and the weight of the body causing the resist- ance, the amount of friction is foiind by multiplying these two quantities together.
The work due to or lost on account of friction, in any given time, is found by multiplying the amount of friction of the moving body by the space passed through in the given time. It is cus- tomary to estimate the amount of friction in pounds, to niake the given time one minute, and to measure the distance passed through in that time in feet. The result obtained will then ex- press the number of foot-pounds of work performed per minute in overcoming friction, and this can readily be reduced to horse- power, or any other desired unit of work. It is important to maintain the distinction between the amount of friction and the work of friction.
The experiments of Coulomb and Morin have demonstrated the following facts in regard to friction :
That it is proportional to the pressure.
With some limitations, that it is independent of the area of the surface pressed, and independent of the velocity of motion.
The limitations are, that the pressure should not be so great as to abrade or wear away the surface rapidly, in which case the friction does not follow the laws enunciated above ; also, that the velocity of motion shall not be so great as to expel the lubri- cant. It is found, for instance, in the case of the journals of car- axles, that they require to be enlarged as the speed increases, in order to prevent the expulsion of the lubricant. The actual bear- ing surface of a journal is usually considered to be the projected area of that journal, or the product of the length multiplied by the diameter. For instance, if a journal is 4 inches in cliameter and 7 inches long, the bearing surface is 28 square inches.
The pressure per square inch on the bearing surface should not exceed the folloAving limits :
Velocity of periphery Limiting pressure per sq. in.
of journal. of Dearing surface.
1 foot per second 382 lbs.
2i feet per second 224 "
5 feet per second 140 "
It is well known that one of the most common expedients for re- ducing the friction between two rubbing surfaces is to interpose some lubricant, which seems to form a coating to the projecting points, making the whole surface more continuous, and thus les- sening the resistance. At very low pressures and velocities the viscosity of the lubricant occasionally causes the resistance to be increased instead of lessened, but in general the effect of an un- guent is to decrease the friction in quite a large ratio. Careful experiments have Ifeen made with regard to the friction between two surfaces when they were perfectly dry and clean, and when
124
ENGINEERING.
different liTbricants were used. In this manner it has been found tliat good oil, such as olive-oil, is one of the best lubricants ; that lard is better than tallow, and that the use of water, instead of lessening the friction, generally increases it. Experiments upon the manner of applying the lubricant show that there is a great advantage in a continual application, so as to keep a film con- stantly interposed between the rubbing surfaces, over the case in which the surfaces are merely kept slightly greasy. Below are given mean values for the coefficient of friction, in cases arising from the sliding of one plane surface upon another, the surfaces being supposed to be true, and, in common language, smooth :
NATrrEE OP THE SLIDING 8UKFACE.
Wood on wood. Wood on metal Metal on metal
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Tn the case of journals, the coefficient of friction is generally much less than for iihine surfaces. Mean values of this coeffi- cient, both for wood and metals, vary from 0. l.>, when the jour- nal is only slightly unctuous, to 0.05, when there is a continual 8U[ pl.V '^f the lubricant. In regard to journal-friction, the amount is independent of the diameter of the journal, but the work re- quired to ovi-rcomo frictiou will of course; be greater with a largo tlian with a small journal, because the distance passed through by the periplu^ry of the journal in a given time will be greater in the former cnse. ^•
liKi/rs, Testing vulcanized rubber for.— These trials consist in examining the comparative degrees of elasticity and tenacity. Tlie manner in whlcli they are conducted in the French navy ap- pears i)ractical and easily followed. Tiie first test consists in cut- ting from the sheets saTn])les, which are left in a steam-boiler under a pressure of 5 atmospheres for 48 hours. At the end of this time, the pieces shoulil not have lost thisir elasticity. The s])eciineiis may theu be i)la<-ed cm the grating of a valve box, un- d(!r a pressure from above of 85.5 ihs. per .s(|uiire inch, and should witlistand 9100 strokes at the rate of 1(»0 jier minute. Specimens not l)oiled should withstand 17.10;) strokes. Thongs of rubber boiled, and having a section O.ti inch sipuire and a length of 8 inches, (ixed between sujjports an<l elonga#d :i.9 inches, should resist, witliout breaking, a further ehmgation of 8 inches, re-
ENGINEERING. 125
peated 22 times a minute for 24 hours. Thongs not boiled, under the same conditions, should resist for 100 hours. These extra elongations may be easily made by a wheel, to the periphery of which one end of the thong is fastened, while the other extremity may be attached to a support. By turning the wheel, any deter- mined elongation may be given at the rate of from 20 to 25 times per minute. Under the above conditions, bands of first quality rubber, perfectly pure and well vulcanized, break after 180 or 200 elongations of 8 times the initial length. Bands cut from pure rubber, but of secondary quality, break after 50 or 60 elongations. Inferior caoutchouc, containing mineral matters or residue of old vulcanized rubber, gives no results at all.
M. Ogier has investigated the properties of rubber belts made of repeated layers of cloth covered with prepared rubber. Through the adhesive nature of the caoutchouc, the superposed tissues form, after vulcanization, a homogeneous substance, comparable, in M. Ogier's opinion, to the best curried leather. His experi- ments, in order to obtain the coefficient of friction of these belts on cast-iron pulleys, give us results varying from 0.42 to 0.84, as against the coefficient for leather, 0.28. The minimum value cor- responds to canvas and rubber belts Avithout an exterior rubber coating. On pulleys of various forms, the maximum value of the coefficient of friction was found on tliose slightly convex and pre- senting a roughly turned surface, this result being inverse to that obtained with leather belts. Similarly the presence of fatty bodies has an opposite action on the cloth and rubber belts to that which it has on- leather. On covering the former with a light varnish of half olive-oil and half tallow, the adhesion was found to be consideraldy augmented. (1) The resistance to traction of rubber and canvas belts per square millimeter (0.0009 square inch) of section, is at least equal to that of leather belts. (2) This re- sistance per square millimeter is independent of dimensions — length, breadth, or thickness. Such is not the case with leather belts, and therefore preference should be given to rubber belting whenever the conditions of the power to be transmitted necessi- tate the employment of very long, very wide, and very thick belts. (3) From two trials it appears that"the external covering of caoutchouc adds nothing to the resistance, and hence it is advan- tageous to use covered belts which, at equal weights and prices, give a superior resistance. (4) Under the same weight, the elastic elongation of leather belts is double that of rubber ones. The permanent elongation, under a change of 0.55 pound per square millimeter, reached 2 per cent in the former and nothing in the latter.
Belts, To prevent gnawing of, by rats. — Anoint with castor- oil.
Belt-Tighteners, To place. — The loss of power occasioned by the use of a tightener, is the power required to bend the belt under that pulley and to drive the pulley. By placing the tightener near the smaller pulley of two of unequal size, there is a greater loss than when it is close to the larger, since the belt requires to be more bent in the former case. The best place, therefore, to
126
ENGINE EKING.
put a tightener, is as close to the larger pulley as it can be ar- ranged to have it work satisfactorily.
UNIVERSAL POINT FOR BOKING-TOOL.
Hangers, Securing. — If it sliould be required to place a hanger between tiooring-l)ciims, the Hoor to which it is attached sliould be strengthened witli a generous ])icc(' of ])lank. For securing hangers, lag-screws are superior to bolts witli nuts, where there is sufficient thickness of wood. A wooden straiglit-edge, reach- ing from on(! bearing to another, is Ijetter for leveling hangers and boxes tliau a twine, wliidi will sag nior(> or less. Some use short cylinders of iron turned to fit the box, and liaving a central hole drilled longitudinally through them. Tliis is an excellent l)lan, as tlie eye nuiy sight through, ora string be ])assed through to determine the level. Where holes are to be bored through the floor clo.se to a wall, post, or other vertical obstruction, a handy tool, similar to tliat shown in the cut, conu»s into ])lay. It is easi- ly forgi^d, and need not be finished with tli<^ elegance of contour shown. A is one of the yokes, and B the cross ; they art^ seisn united at C. 'i'he shaidv of out' yoke has a tapering s<|uar(! hole to receive a bit or auger, and tin; other is a ta])ering stjuare shank to fit a stock of the bit-l)race. Tlie device is " a universal joint," and can be readily worked at an anglt! of 4/)^.
IIo'P liKAUiNc; ;\i,AiiM. — A cylindrical box, A, is jji-ovidrd with a jjerforated bottom, H, and i)laced directly over the journal. 'i'he box is filled wilh a pre])ared grease which nudts at a certain trmperatnre, to which it must be raised by the shaft becoming hot. As till- coiriiiciiinil iii|Mi(it'M iind c■^;(•ll|les through tln' |p('rforii
ENGINEERING.
127
tions, a disk, (", which rests thereon, descends, thereby tilting the lever, D, and so making contact between the plates, E and F. The latter are connected by an electric circuit with a bell which
HOT-BEARING ALARM,
sounds when the current is established. The pipe, G, serves for the ordinary lubrication of the journal. It is suggested that this device might be profitably used upon journals not readily acces- sible.
Pulleys, Balancing.— Swing the pulley on arbors between lathe-centres, and note the position as determined by gravity. On
CONE XtTLLEYS, FIG. 1.
the top side, drill and tap two holes, in which seat machine screws with flat heads, the shanks projecting through from the face or
128
ENGINEERING.
outer side. Then, by pecurinj^ pieces of iron as weights to this point until the pulley is balanced, the amount necessary to balance the pulley is found. This amount of lead is then melted and cast in a mould formed by clay. The screws serve to hold the lead in place.
Pulleys, To design cone. — The following rules will enable any one who understands arithmetical operations to make the calcu- lations necessary for designing a set of cone pulleys in such a manner that the belt can be shifted from one pair to another, and be equally tight in every position. There are six cases to be con- sidered
CONE PULI.EY.1, Fid. 2.
Case 1. — Crossed belt jxissing over two continuotis cones. (Fig. 1 .) — In this case, it is only necessary to use two similar conical drums, with their large and snuill ends turniHl ojjposite way.s.
Cask 2. — Crossid belt pasHiittj over tiro stepped eones that are equal and opposite. (Fig. 2.) Draw vertical lines, A B, CD, etc., to tlie axes of tlie pulleys, at a distance apart e(]ual to the face of a pulley. Lay off, on each si(l(M)f tlie axis, distances, ab, ac, e(jual to tlie radius of Ihc largest piilii-y, and d r, d f, e(|ual to tlic radius of tli'i smaJlrst pulley. Draw a siraiglit line, li .M, llnDUtrli i)an(l e, and !S () lliiMugli c and f. 'I'lu- points in which llu-se lines rut the verticals detennini' the radii of tlie intermediate ])ulleys.
Cask ;{. — (Jros.sed heft pussiiuj orer ain/ tien .ntepped cones. — As- Bume values for the radii of one dri\ ing-pulh-v and the corre- sponding driven pulley. 'I'lieii, for any asHuiiied radius of a
ENGINEERING.
129
second driving-pulley, the radius of the driven pulley must have such a value that the sum of these two radii is equal to the sum of the first two. The same must be true for every pair of pulleys in the two stepped cones.
Example. — Suppose the radius of the first driving-pulley is 15 inches, and of the first driven pulley 5 inches. Now, if there are five steps in the driving-cone, having radii of 15, 12, 9, 6, and 3 inches respectively, the corresponding steps of the driven cone will have radii of 5, 8, 11, 14, and 17 inches, since the sum of the radii of each pair of pulleys must be equal to the sum of the radii of the first pair, or 20 inches. It will be evident from the foregoing that, in the case of crossed belts, the construction of cone-pulleys is very simple, since it is only necessary to observe the directions given above, no matter what the distance between the centres of driving and driven pulley may be.
CONE PTTLI/EYS, FIG. 3.
Case 4. — Open belt passing over two continuous pulleys. (Fig. 3.)
For this case equal and similar conoids must be used. Assume the largest radius, AF, and the smallest, B D, and calculate, by the rule on page 111, the length of belt required for pulleys with the given radit, the distance, K L, between their centres being given. Then the middle radius, C H, is found by the following rule :
Subtract twice the distance between centres from the length of the belt, and divide the difference by the number 6.2832.
Having found the middle radius, draw circular arcs through the points F H D and G I E, thus determining the section of the conoid.
Example. — Suppose that the largest radius is 24 inches, the
130
ENGINEERING.
smallest 6 inches, and the distance between centres of conoids 3 feet. What should be the middle radius ?
First find the length of belt : 3 diminished by 0.5 equals 1.5. This divided by 3 equals 0.5, and the corresponding number in table of factors, page 111, is 1.047— (1). 1.047 multiplied by 1.5 equals 1.571 — (2). 2 added to 0.5 equals 2.5, which multiplied by 3.1416 equals 7.854 — (3). 3 multiplied by 3 equals 9, which less 2.25 equals 6.75. 1.5 multiplied by 1.5 equals 2.25. The square root of 6.75 is 2.6, which multiplied by 2 equals 5.2— (4). The sum of 5.2 and 1.571 and 7.854 equals 14.625, wliich is the length of belt. Then find the middle radius by the preceding rule : 3 multiplied by 2 equals 6. 14.625 less 6 equals 8.625, which divid- ed by 6.2832 equals 1.373 feet, or about 16i inches middle radius required.
co.NK inn.i.KYs, pio. 4.
Case 5. — Opni hrlt passinr/ over two stepped roncx that are equal and oppositf. — (Fig. 4.) — The construction will be evidtMit from the figure, it only being nece.s.sary to form two continuous conoids, UH explained above, and divide tliciu into the rctjuiri'd number of
Ht(!p«.
("ahkO. — (^)pni, Ixit pasHiiHj iirrr an// tiro ><t(j)/)(<l cdhis. — Th(^ ruUrs for this case, originally demonstrated ])y J. li. Ilenek, are jiresented below in a siniiililied fnrni. Kirst assnme the radii of <me driving-j)ulley and tliu corresponding driven pulley, measure the distance between tlu-ir centres, and find the length of belt re-
ENGINEEKING. 131
quired. Then assume values for the radii of the successive pul- leys on the driving-cone, and calculate the values of the corre- sponding radii on the driven cone by the following rules : I. Hav- ing assumed the value of one radius, it is first necessary to ascer- tain whether the one to be calculated is larger or smaller. (1) Multiply the assumed radius by the number 3.1416, and increase the product by the distance between the centres of the pulleys. (2) If the quantity obtained by (1) is greater than half the length of the belt, the assumed radius is greater than the one to be de- termined. (3) If the quantity obtained by (1) is less than half the length of the belt, the assumed radius is less than the one to be determined. II. When the assumed radius is the greater of the two, to find the other one. The distance between centres and the length of belt are supposed to be given. (1) Multiply the as sumed radius by the number 6.2832, subtract this product from the length of the belt, and divide the remainder by the distance between centres. (2) Add the quantity obtained by (1) to the number 0.4674, and extract the square root of the sum. (3) Subtract the quantity oljtained by (2) from the number 1.5708, and multiply the difference by the distance between centres. (4) Subtract the quantity obtained by (3) from the assumed radius ; the remainder will be the required radius. III. Wlien the assumed radius is the smaller of the two, to find the other one. (1) Same as (1) of preceding rule. (2) Same as (2) of preceding rule. (3) Subtract the number 1.5708 from the quantity obtained by (2), and multiply the difference by the distance between centres. (4) Add the quantity obtained by (3) to the assumed radius ; the sum v?ill be the required radius.
E.mmple. — The first driving-pulley of a stepped cone has a ra- dius of 12 inches, and the radius of the corresponding driven pulley is 4 inches ; the distance between centres of pulleys is 3 feet, and there are three other pulleys on the driving-cone, having radii of 9, 6, and 3 inches respectively. It is required to find the radii of the corresponding pulleys on the driven cone. It will be necessary first to calculate the length of belt required, which is 10.334 feet, or about 10 feet 4 inches.
Next find whether the pulleys on the driving or driven cone are the largest. Half the length of belt is 5.167 feet. For the 9- inch pulley, 0.75 multiplied by 3.1416 is 2.356, and adding 3, the sum is 5.356, wliich is greater than 5.167, showing that the 9-inch pulley is larger than the pulley to be determined. For the 6-inch pulley: 0.5 multiplied by 3.1416 equals 1.571, and increased by 3 equals 4.571, and as this is less than 5.167, the 6-inch pulley is smaller than the pulley to be determined. Of course, then, the remaining 3-inch pulley is still smaller than the corresponding pulley in the driven cone.
To find the radius of the pulley corresponding to the one on the driving-cone whose radius is 9 inches : (1) 0.75 multiplied by 6.2832, 4.712. Subtracting 4.712 from 10.334, the remainder is 5.622 ; 5.622 divided bv 3, 1.874. (2) 0.467 added to 1.874, 2.341. Square root of 2.341, 1.53. (3) Subtracting 1.53 fnmi 1.571, the remainder is 0.041 ; 0.041 multiplied by 3, 0.123. (4) Subtract- ing 0.123 from 0.75, the remainder is 0.627 feet, or about 7^ inches, radius of required jjulley.
132 ENGINEERING.
Pulley corresponding to driving-pulley whose radius is 6 inches : 0.5 multiplied by 6.2833 equals 3.142. This subtracted from 10.334 equals 7.192, which divided by 3 equals 2.397— (1). Adding 0.467, we have 2.864, the square root of which is 1.692 — (2). 1.692 diminished by 1.571 equals 0.121, which multiplied by 3 equals 0.363 — (3). Adding 0.5 gives 0.863 feet, or about lO^Y inches, required radius.
Pulley corresponding to driving-pulley whose radius is 3 inches : 0.25 multiplied by 6.2832 equals 1.571. This, subtracted from 10.334, equals 8.763. Dividing the last by 3 gives 2.921— (1) ; and by adding 0.467 we have 3.388. Of this the square root is 1.841 — (2). Subtracting 1.571 givesO.27, which multiplied by 3 equals 0.81, and adding 0.25 gives 1.06 feet, or about 12^ inches, required radius.
The radii of the several pulleys on the two cones then will be :
Driving-cone 12, 9, 6, 3 inches.
Driven cone 4, 7^, 10^, 12r6 inches.
B.
Pulleys, Set-screws for. — These should be made of cast-steel with hollow points ; the ends should then be beveled to an edge surrounding the hole, and tempered to a dark straw. When set up, these screws cut circular indentations on the shaft, and exert an enormous force of resistance.
Pulleys, Working value of. — Pulleys covered with leather, iron pulleys polished, and mahogany pulleys polished, rank for working value as 36, 24, and 25 \nn- cent respectively, wood and iron uncovered being almost identical.
Rawhide Boxes for machinery. — A ])ractical machinist says : " I have run a piece of nuicliiu«-ry in rawhide boxes for fourteen years without oil ; it is good yet, and runs at 4500 per minute. I put it in while soft, and let it remain until dry."
SiiAFTiNfi Accidents, Preventing. — Accidents are common in large nuiniifactorics tlirougli tlu; cngagcnient of some jjortion of a workman's garments witli a swiftly rotating shaft. A .siyi])le way of rendering these casualties inqiossibh; is to cover the shaft with a loose sleeve along its whole length. 'I'he sleeve may be of tin or zinc, and made so as to be removable if -desired. The friction between it and the shaft would be sufficient to cause its rotation with tlie latter, biit of course, in event of a fabric be- coming wrapped around it, it would <|uick!y stop, and allow of the easy extrication of the same. 'J'he sleeve should be lined with leather both witliiu and at the ends in order to ])revent noise. Thcs same idea in the sluipe of loose covers miglit readily be applied to cog-wlu^els or pulleys.
SiiAKTiN(!, Lining. — Evc^y out! operating long lines of shaft- ing should provide an adjusting roil, as shown in the (engraving. A may be a rod or a pier*; of gus])ipe, of suflicient length to nrach from llie simft, (), to within about 4 feet of the floor ; an ofTsca i)i(;ce, M, is fixed to the. top of this rod, which earries a riglit and ]»;ft iiand screw, C ; two jaws, D, travel u|i<in this BCrow, one upon tlm right and the otlier uixin the ht'l hand
ENGINEERING.
133
thread, as shown. The screw may be worked by a ;J:-in. wire, E, with a crank, F, at its lower end ; if a gas-pipe is used, the wire may pass through the pipe, and the lower end of the screw, C, enter the top of the pipe as a bearing. If the rod, A, is of wood, three or four wire staples will suffice as guides for the wire, as indicated. A tar- get, Q, with a clamp-screw, slides upon the rod, for the purpose of easy adjustment to the sights of the leveling instrument.
Now it will of course be apparent to every one that, whenever several sizes of shafting occur in the same line, this ad justing- rod will always give the exact central distance, O, of the shaft from the target ; hence we have only to plant the leveling instrument in a position to com- mand a view of the target when suspend- ed from each of the several bearings of a line of shafting, in order to adjust the lev- el of a line with the utmost expedition and accuracy. An engineer's tripod and level is, of course, the best instrument for this pui'pose, but, when this is not at hand, an ordinary builder's level may be used : the longer it is, the better. Fix a temporary sight at one end of the level ; a piece of tin (with a small pin-hole) next the eye, and a piece of tin or thin wood with a large hole at the farther end, with a vertical and a horizontal thread stretch- ed across the hole, with their point of intersection the same distance above the level as the hole in the eye-piece. The level may be used upon a level stand or table, some five feet from the floor.
To adjust a line of shafting laterally, an adjusting-rod must of course be used horizontally in connection with a strong line, stretched as taut as possible, at such distance from the shafting as to need nearly the full length of the rod to reach it. The reason for placing the line at such a distance from the shaft is to pre- vent the difference in level between the line and the shaft from materially impair- ing the truth of the result. If the line is very long, it will sag so much that a plumb-line suspended from the measuring
point of the target or rod may be neces- „g,,j^.p^ ^^^^ ^^^^^^ sary for perfect accuracy. shafting.
The jaws, D, should be so formed that they may be applied to the inside of boxes. Pivot-boxes are
134 ENGINEERING.
now so generally used, however, that this application of the rod is not so common.
Shafts, Sprung:. — If a shaft sprintrg in running, the trouble lies probably in either a too small diameter of the shaft for its weijrht and velocity, a set of unbalanced pulleys, or an unequal strain on either side by the belts.
Wood, Lubricant for. — A mixture of black-lead and soap.
PEACTIOAL TECHNOLOGY.
CEMENTS, GLUES, AND MOULDING COMPO- SITIONS.
Casts, To prepare plaster of Paris for.— Immerse tlie unburnt ' gypsum for 15 minutes in water containing 8 or 10 per cent of sulphuric acid, and then calcine it. Prepared in this way it sets slowly, but makes excellent casts, which are perfectly white instead of the usual grayish tint.
Casts, Transparent. — Beautiful semi-transparent casts of fancy articles may be taken in a compound of 2 parts unbaked gyp- sum, 1 part bleached beeswax, and 1 part paraffine. This be- comes plastic at 130°, and is quite tough.
Cements. — Aii' and imter-tight, for casks and cisterns : Melt- ed glue 8 parts, linseed-oil 4; boil into a varnish with litharge. This hardens in 48 hours. Plumbers' : Black resin 1 part, brick- dust 2. Melt together. For leaky boilers : Powdered litharge 2 parts, fine sand 2, slaked lime 1. Mix with boiled linseed-oil. Apply quickly. Acid-proof : A paste of powdered glass and concentrated solution of water-glass. Cutlers' : (1) Pitch 4 parts, resin 4, tallow2, and brick-dust 2. (2) Eesin 4, beeswax 1, brick- dust 1. (3) Resin 16, hot whiting 1, wax 1. This is used for fas- tening blades in handles. For ivory or tnother-of -pearl : Isinglass 1 part, white glue 2, dissolved in 30 parts hot water and evaporated to 6 parts. Add gum-mastic ^ part, dissolved in \ part alcohol, and add 1 part zinc- white. Shake up and use warm. Jeiceler's, for ■uniting all substances : Gum -mastic 5 or 6 bits as large as a pea dis- solved in spirits of wine sufficient to render all liquid. In another vessel dissolve the same amount of isinglass in rum enough to make 2 ozs. of strong glue, adding 2 small pieces of gum ammo- niacum, which must be moved until dissolved. Heat and mix the whole. Keep in a closely-corked phial, and put the latter in boiling water before using. Black, for bottle-corks : Pitch hard- ened by the addition of brick-dust and resin. For jet : Use shel- lac, warming the edges before applying, and smoke the joint to make it black. For meerschaum or china : (1) Make a dough of garlic, rub on the edges and bind tightly together. Boil the object for half an hour in milk. (2) Use quicklime mixed to a thick cream with white of egg. Soft, for steam-boilers : Red or white lead in oil 4 parts, iron borings 3 parts. Oasfitters' : Resin 4^ parts, wax 1, Venetian red 3. Chopper smiths' : Boiled linseed- oil and red lead made into a putty. This is used to secure joints and on washers. For emery on to icood : E(]ual parts of shellac, white resin, and carbolic acid in crystals. Add the acid after the
136 rRACTICAL TECHNOLOGY.
others are melted. Iron and emery : Coat the meta. with oil and white-lead, and when hard apply the emery mixed with fjlue. Firnch ]mtfy,hni'd and permanent: Linseed-oil 7 parts, brown umber 4, boiled for 2 hours, ^ part white-wax stirred in. Re- move from fire and thoroughly mix in white-lead 11, and fine chalk 5^ parts. India-rubher : Fill a bottle -^q full of native india-rubber cut into fine shreds. Pour in benzole from coal-tar till the bottle is f full. The rubber will swell ; and if the whole be shaken every few days, the mixture will become as thick as honey. If too thick, add benzole ; if thin, add rubber. This dries in a few minutes, and will unite backs of books, straps, etc., very firmly. C7iinese, for fancy articles, wood, yhtsfi, etc. : Finest pale-orange shellac, broken small, 4 parts, rectified spirit . 3 parts. Keep in a corked bottle in a warm place until dissolved. It should be as thick as molasses. liust joints : (1) Clean iron borings 2 parts, flowers of sulphur jV. sal-ammoniac -j^-. (2) Finely-powdered iron borings 1 part, sal-ammoniac ^, flowers of sulphur T^;. Pound together and keep dry. For use, mix 1 part with 20 of pounded iron borinors, and mix to a mortar consis- tence with water. F'or making metallic joints soinul : (1) Use a i)utty of boiled linseed-oil and red-lead. (2) Use &, putty of equal parts of white and red lead. For electrical and chemical appartdtis : Resin 5 parts, wax 1, red ochre 1, plaster of Paris \. Melt at moderate heat. For mending stone, or as mas- tic for brick walls : Make a paste of linseed-oil with clean river sand 20 parts, litluir<re 2, quicklime 1. For chucking work in the lathe : (1) Black resin 8 parts, yellow wax 1 ; melt togetlier. For use, cover the chuck to Vg in. thick, spreadinjr over the surface in small pieces, mixing it with -jlr its bulk of gutta-percha in thin slices. Heat an iron to dull red and hold it over the chuck till the mixture and gutta-])crcha are melted and rKpiid. Stir the cement with the iron until it is smoothly mixed. Chuck the work, lay on a weight to enforce contact, and let it rest for half an hour before using. (2) Burgundy pitch 2 ))arts, resin 2, yellow wax i, dried wax 2. Melt and mix. (3) Resin 4 parts, nudted with pitch 1. While boiling add brick-dust until dro])])ing a little on stone shows the mixtures to be sufficiently liard. /'J/astic, for leather or india-rubber : Hisuljjhidr of carbon 4 ozs., shrcd- d(^d india-rubber 1 oz., isinglass 2 drachms, gutta-pt'rcha ^ oz. Dissolve, coat the jjarts, dry, tlien heat the layer to melting, place and press the parts together. Water-tight, for iroodcn vessels : Lime, clay, and oxidt^ of iron, mixed, kfpt in a close vessel and conqinundcd with water fur use. Fi>r huther, Htrojis, etc. : (Jut- ta-pcrcha dissolved in bi.siiiphidi; of carl)on. Kec]) tightly cork«'d and cool. It sliouid be of tlie consistenct'of molasses. For mar- ble, or for attaching glass to metal: Plasler of Paris soakinl in a Hafiirated solution of alum and baked hard, (iiiud to powdi-r and mix witii wat(U' for use. Can be colonul to imitate! any marble, and takes a fine p<»Iish. hnp(rri<nis, J'or corks, etc. : Zinc-whit(! rubbed up willi co|)al varnish. (Jiv») two coats so as to fill all tlie ]inri's, and liuisli with varnish alone. For cracks in wood: (1) Slak<;d lime 1 part, rye meal 2, and linseed-oil 2. (2) Use a paste of sawdust and ]>re|)are(l chalk with glue 1 ])art, dissolved in water 10. {'<)) Uil-vainish thickened with equal
PKACTICAL TECHNOLOGY. 137
parts of litharge, clialk, and white and red lead. For wood and glass or metals : (1) Resin and calcined plaster, the former melted, made into a paste. Add boiled oil to consistence of honey. (2) Dissolved glue and wood-ashes to consistence of varnish. Fire- proof and irater -proof : Pulverized zinc- white, sifted peroxide of manganese, equal parts. Make into a paste with soluble glass. To mend iron pots and pans : Partially melt 2 parts sul- phur, and add 1 part fine black-lead. Mix well, pour on stone, cool, and break in pieces. Use like solder with an iron. London cement, for glass, wood, china, etc.: Boil a piece of cheese three times in water, each time allowing the water to evaporate. Mix the paste left with quicklime. For aquaria : (1) For fresh water aquaria : Take \ gill gold-size, 2 gills red-lead, 1^ gills litharge, and sufficient silver sand for a thick paste. This sets in about 2 days. (2). For fresh or salt water : Take ^ gill powdered resin, 1 gill dry white sand, 1 gill litharge, 1 gill plaster of Paris. Sift ; and for use mix with boiled linseed-oil to which a little dryer has been added. Mix 15 hours before using, and allow 2 or 3 hours to dry. For petroleum lamps, impervious to the oil : Re- sin 3 parts, boiled with water 5 and caustic soda 1. Then mix with half its weight of plaster of Paris. This sets in f hour. Roman : Green copperas 3^ lbs., slaked lime 1 bushel, fine gravel sand 1 bushel. Dissolve the copperas in hot water, and mix all to proper consistence. Keep stirred. Glass to glass, for sign- letters, etc. : Melt in a water-bath liquefied glue 5 parts, copal varnish 15, drying-oil 5, oil of turpentine 2, turpentine 3. Add slaked lime 10. Hydraulic : Oxide of iron 1 part, powdered clay 3, and boiled oil to a stiff paste. Stone : Sand 20 parts, litharge 2, quicklime 1, mixed with linseed-oil. Leather and cloth, for uniting parts of boots and shoes, seams, etc. : Gutta- percha 16 parts, india-rubber 4, pitch 2, shellac 1, oil 2. Mix and use hot. Mahogany : Shellac melted and colored. Colorless, for paper : Add cold water to rice-flour, mix, bring to proper con- sistence with boiling water, and boil one minute. Water-proof, for cistern stones : (i) Whiting 100 parts, resin 68, sulphur 18+^ tar 9. Melt together. (2) Sand 100 parts, quicklime 28, bone ashes 14, mixed with water. Transimrent : India-rubber 75 parts, chloroform 60. Mix, and add mastic 15. Cloth to iron : Soak the cloth in a dilute solution of galls, squeezing out the superfluous moisture, and applying the cloth, still damp, to the surface of the iron, which has been previously heated and coated with strong glue. The cloth should be kept firmly pressed upon the iron until the glue has dried. For cracks in stoves: Finely- pulverized iron (procured at a druggist's) made into a thick paste with water-glass. The hotter the fire, the more the cement melts and combines, and the more completely does the crack be- come closed. For china, glass, etc. : Diamond cement, for glass or china, is nothing more than isinglass boiled in water to the consistence of cream, with a small portion of rectified spirit added. It must be warmed when used. 2. White-lead rubbed up with oil. Articles mended with this must stand for a month. For corks of benzine-bottles : A paste of concentrated glycerine (commonest kind) and litharge. This soon hardens, and is'insolu- ble in benzine or any of the light hydro-carbon oils. For eaustie
138 PKACTICAL TECHNOLOGY.
lye tanks • The tanks may be formed of plates of heavy-spar, the joints being cemented together by a mixture of 1 part finely divided india-rubber dissolved in 2 parts turpentine oil, with 4 parts powdered heavy-spar added. Colored : Soluble glass of 33** B. is to be thoroughly stirred and mixed with fine chalk and the coloring matter well incorporated. In the course of six or eight hours a hard cement will set. The following are the coloring materials : 1. Black : Well-sifted sulphide of antimony. This can be polished with agate to a metallic lustre. 2. Gray-black : Fine iron-dust. 3. Gray : Zinc-dust. This has a brilliant lus tre, and may be used for mending zinc castings. 4. Bright green : Carbonate of copper. 5. Dark green : Sescjuioxide of chromium. 6. Blue: Thenard's blue. 7. Yellow: Cadmium. 8. Bright red : Cinnabar. 9. Violet red : Carmine. 10. Pure white : Fine chalk as above.
Cement, Portland, To test. — Three tests are used : (1) Resist- ance to tensile force. (2) Specific gravity. (3) Water test. The first is by making a specimen briquette in a mould with a trans- verse section of 2.25 square inches, the specimen being held ver- tically in clips, which is placed under the .-^hort arm of a steel- balance, and broken. A test of 500 lbs. has been used on an area of 2.25 square inches after 7 days' immersion in water. The sec- ond method is by finding the weight in ])ounds of the struck bushel. The water test is useful when the others can not be ap- plied. It consists of gauging a small quantity of the dry powder with water, and immediately immersing it in water. If the shari)er edges crack or break away after a short time, the cement is too hot or fresh, or is inferior in quality. The weight of good Portland fement ranges from 100 lbs. to 130 lbs. per bushel, equal to from 80 lbs. to 102 lbs. per cubic foot. The lighter kinds set more rapidly than the heavier, but are weaker. The specific gra- vity should be of 110 lbs. to a bushel.
Glued Joints, Strength of. — Tlu; absolute strength of a well- glued joint is given as follows in pounds per square inch :
|
Across the grain. |
With the grain |
|
|
Beech, |
2133 |
1095 |
|
Elm, |
1436 |
1134 |
|
Oak, |
1735 |
568 |
|
Whitewood, |
1493 |
841 |
|
Maple, |
1422 |
896 |
It is customary to use from ^ to -^ of the above values to cal- culate the resistances wliich surfaces joined with glu(* can perma- nently be submitted to with safely.
CJlue, Fire-i)n)of. — A handful of <iuicklime mixed in 4 ozs. of linseed-oil and boiled to a good thickness Tuakes, wiien spread on plates and hardened, a glue which can be used in the ordinary way, but wliidi will resist (ire.
Glue, Li<iui(i. — Dissolve the glue in an e(|uai amount of strong hot vinegar, adding \ alcohol and a little alum. Will keep in- definitely.
Glueh, Marine. — (1) Pure india-rubber 1 pt., dissolved by heat
PRACTICAL TECHNOLOGY. ^39
in naphtha ; when melted, iidd shellac, 2 pts. (2) Glue, 13 pts., water to dissolve, and yellow resin, 3 pts. Melt, add turpentine,' 4 pts., and mix. Portable, for draughtsmen : Glue 5 ozs., sugar 2 ozs., water 8 ozs. Melt in water-bath, cast in moulds, and dis- solve for use in warm water. Fur bank-notes : Fine glue or gelatine, 1 lb., dissolved in water, and the water evaporated until nearly expelled. Add I lb. brown sugar, and pour in moulds. For gutta-percha: Common black pitch 2 pts., guttapercha 1 pt. Mould into shape. Elastic : Dissolve glue in a water-bath, evapo- rate to a thick tiuid, and add an equal weight of glycerine. Cool on a slab. Liquid : (1) White glue 16 ozs , dry white-lead 4 ozs., soft water 2 pints, alcohol 4 ozs. Stir and bottle while hot. (2) Glue 3 pts. softened in 8 parts water. Add i pt. muriatic acid and I pt. sulphate of zinc. Heat to 176° Fahr.''for 12 hours. Al- low the compound to sei tie. Beat and moisture-proof; Linseed- oil 4 ozs., 1 handful of quicklime ; boil to good thickness, and cool. It will become very hard, but is as easily dissolved as com- . mon glue. Water-proof, simple : Common glue 1 lb. boiled in 2 qts. skimmed milk.
Glue, Test for goodness of. — Assuming that that is the best glue which will take up most water, take 50 grains of the speci- men and dissolve it in 3 ozs. water in a water-bath. When dis- solved, set it by for 12 hours to gelatinize, and tlien take an ounce chip-box, place it on the surface of the gelatine, and put shot into the box until it sinks down to a nuirk on the outside. It will be found that the stronger the glu--, the more shot it will take to sink the box down so that tlie mark sliall be level with the surface of the gelatine. In a trial with very fine glue, 50 grains of glue dissolved and gelatinized with 3 ozs. of water, supported to the mark on the box 6 ozs. of shot, at a temperature of 58" Fahr. On trying the same experiment with best Kussian isinglass, 9 ozs. of shot were supported, the temperature being the same. This test is of course intended as a comparative one between two kinds of glue, or between any kind taken as a stand- ard and another compared with it. The "placing of the mark is arbitrary.
Gluk, To bleach. — Soak in moderately strong acetic acid for two days, drain, place on a sieve, and wash well with cold water. Dry on a warm plate.
Moulding Architectural Ornaments. — A good composition for this purpose is made of chalk, glue, and paper-paste.
Moulding Composition.— Five parts of sifted whiting mixed with a solution of 1 part glue, together with a little Venice turpen- tine to obviate the brittleness, makes a good plastic material, which may be kneaded into figures or any desired shape. It should be kept warm while being worked. It becomes as hard as stone when dry.
Paste, To mould figures in. — Take the crumb of a new-drawn white loaf, mould in a mass until the whole becomes as close as wax and very i)liab]e. Then heat and roll with a rolling-pin. Mould it to the required shape, and dry in a stove.
140 PRACTICAL TECHNOLOGY.
PhotoCtRAPHIC Prints, To varnish. — Heat a piece of glass, and rub a little wax over it with a bit of cottou-wool. Pour water over the plate, and press the picture down upon it with a piece of filtering-paper. When dry, the picture is removed, and ■will be found to possess a brilliant surface.
Picture-Frames, Composition for. — (1.) To make composi- tion ornaments for picture- frames : Boil 7 lbs. best glue in 3| pints water, melt 8 lbs. Avhite resin in 3 pints raw linseed-oil ; when the ingredients are well boiled, put them into a large ves sel and simmer them for half an hour, stirring the mixture and taking care that it does not boil over. When this is done, pour the mixture into a large quantity of wliitlng, previously rolled and sifted very fine, mix it to the consistence of dough, and it is ready for use. (2) Dissolve 1 lb. glue in 1 gallon water ; in another kettle boil together 2 lbs. resin, 1 gill Venice turpentine, and 1 ])int linseed-oil ; mix together in one kettle, and continue to boil and stir them together till the water has evaporated from the other in- gredients ; then add finely-pulverized whiting till the mass is brought to the consistence of soft putty. This composition will be hard wlien cold ; but being warmed, it maj' be uioulded to any shape by carved stam]>s or jnints, and the moulded figures will soon become dry and hard, and will retain their shape and form permanently. Frames of either material are well suited for gild- ing.
Plaster Casts, To toughen. — Immerse in a hot solution of glue long'enough for the mass to be well saturated. They will bear a nail driven in witliout cracking.
Plaster Models, Mending. — Sandarac varnish is the best ma- terial. Saturate the broken surfaces thoroughly, press them well together, and allow them to dry.
Plaster Moulds. — Glycerine is said to be a good coating for the interior, but ])ractical plaster moulders still use, as of old, a mixture of lard and oil.
METAL- WC)RKING HINTS A^)KE('irES.
Ai.iiOV for filling defects in small castings. — Lead !) parts, antiniuny 2, bi.-^nnith 1. Tliis expiinds on cooling.
Alloy ok Cori'Elt, which will attach itsilf to glass, metal, or ]K>rcelaiii. — 20 to 30 parts finely ijleiidcd cnppi'r (made by n-duc- lion of oxide of ro])per witli hydrogen or ))recipitation from solu- tion of its suljjhate with ziiw) are made intn a paste with oil of vitriol. To tills add 70 parts mercury ami triturate well ; then wash out the acid with Itoiling waiter and allow llie conii)ound to cool. In 10 or 12 hours, it Ijecoines sullicieiitly hard to receive a brilliant indish and to scratch the surface of tin or gold. When heated it becomes plastic, but does not cf)ntracton cooling.
Alloy, " Ohdikk." — This is made of pure copper 100 parts, tin 17 partH, mugnesia (i parts, Bal-aminoniac 3J parts, fpiicklinie 1^
PRACTICAL TECHJfOLOGY. 141
parts, tartar of commerce 9 parts. The copper is first melted, then th ' magnesia, sal-ammoniac, lime, and tartar in powder are added Litle by little and briskly stirred for half an hour. The tin is lastly mixed in grains until all is fused. The crucible is covered, and the fusion maintained for 3o minutes, when the dross is skimmed oif and the alloy is ready for use.
Alloys, To extract silver from old. — Dissolve in nitric acid and precipitate the chloride of silver with a solution of common salt. The silver is reduced to a pure state by mixing the chloride with an equal weight of bicarbonate of soda and sij^elting in a common sand crucible.
ALLTbiiNUM Silver. — The following alloy is distinguished by its beautiful color, and takes a high polish : Copper 70, nickel 23, aluminum 7, total 100.
Babbitt Metal. — There are a large number of recipes for this alloy, but the following gives an excellent composition for gene- ral use : Tin 50 parts, antimony 5 parts, copper 1 part.
Bell, Cracked, To repair. — A cracked bell which gives a jar- ring sound may be improved by sawing or filing the ruptured edges so that they are not brought together by the vibration of the blow.
Boiler-tubes, Iron, To preserve. — A coating of red-lead and boiled linseed-oil, applied to iron boiler-tubes, acts as a great preservative.
Brass, Black stain for. — Arsenious acid 2 parts, hydrochloric acid 4, sulphuric acid 1, water 80.
Brass Scrap, To utilize.— The best way is to melt it in with new brass, putting it in with the zinc after the copper is melted.
Brass, To blacken. — ISIix 4 parts hydrochloric acid and 1 part arsenic (by weight) ; put on bright, dry, and lacquer.
Brass, To clean. — Rub bichromate of potash fine, pour over it about twice the bulk of sulphuric acid, and mix this with an equal quantity of water. The dirtiest brass is cleaned by this in a trice, ^^'ash the metal immediately after in plenty water ; wipe, rub dry, and polish with powdered rottenstone.
Brass, Vert de Bronze on. To produce. — Dissolve 2 ozs. ni- trate of iron and 2 ozs. hyposulphite of soda in 1 pint water. Immerse the articles till they are of the required tint, as almost any shade from brown to red can be obtained ; then wash well with water, dry, and brush. One part perchloride of iron and 2 parts water mixed together, and the brass immersed in the liquid, gives a pale or deep olive-green, according to the time of immersion. If nitric acid is saturated with copper, and the brass dipped in the liquid and then heated, the article assumes a dark- green color.
Bronze for gongs and cymbals. — This is made with 20 per cent of tin, and is hammered into shape while at a red heat ; it is then tough and malleable, but is very brittle when cold.
Bronze for small castings. — Fuse together 95 part of copper and 36 parts of tin.
142 PRACTICAL TECHNOLOGY.
Bronze, Green. — Tlie bluish-green bronze used for ornamental articles is made of any metal, first covered with a varnish made of ground tin or bronze powder rubbed up with honey in gam- water. Then wash with a mixture composed of sal-ammoniac ^ oz., common salt ^ oz., and 1 oz. spirit of hartshorn in 1 pint vinegar. After applying tlie mixture, leave for a day or two in tne sun, and then, if necessary, add a second coat. This is a good way to renovate old gas-fixtures.
Bronze, Japanese. — A curious bronze is produced in Japan, which, when mad#in thin plates, resembles slate, and is covered with designs in silver. It contains, in addition to copper, from 4 to 5 per cent of tin, and on an average 10 per cent of lead. The combination is easily moulded into thin plates. Tiiese are var- nished, and through the covering the designs are scratched with a burin. The plate is then plunged in a silver-bath, when the silver is deposited on the unprotected portions. Lastly, it is placed in a muffle-furnace, when the copper blackens and the silver remains bright.
Bronzing Hardware. — Brown bronze dip, for coating liat- hooks and similar small hardwaie articles, is made of iron scales 1 lb., arsenic 1 oz., muriatic acid 1 lb., zinc, solid, 10 ozs. The zinc should be kept in only when the bath is used. The castings must be perfectly free from sand and grease.
Case-hardening, to be quickly performed, is done by the use of prussiate of potash. This is powdered and spread upon the surface of the iron to be hardened, after the iron is heated to a bright red. It almost instantly fluxes and flows over the surface ; and when the iron is cooled to a dull red, it is plunged in cold water. Some prefer a mixture of ])russiatt' of potash 3 parts, sal-ammoniac 1 part ; or prussiate 1 part, sal-amnnmiac 2 parts, and iincly-powdered bone-dust (unburned) 2 parts. The appli- catiim is the same in each case. Proper case-hardening, when a deep coating of steel is desired, is done by ])acklng the article in an iron box with horn, hoof, bone-ilust, shreds of leather or raw liide, or either of these, and heating to a red lieat for from 1 to 3 hours, then plunging the box into water.
Chain, Strength of. — To ascertain the strength of short-linked chains: (1) Multiply the scjuare of the diameter (reckoned in six- teentlis of an incli) by .035 ; the ])roduct will be the weight the chain will support in tons. ('^) The square of the diameter in eighths of an inch = weight of chain in lbs. ])er fathom. The s(|iiare of the diameter in eighths ■*■ 2 = breaking weight in tons. Thus for a chain nnido of f iron, the weight = 3'' = 9 lbs. i)er
fathom, and its breaking weight would be -2-1 = A\ tons. The ut
most loud i)ut upon it should not exceed 1\ tons, the safe con- stant load heing IH to 20 cwt.
Coloring .Mktai.s. — Take liyposulphito of soda 4 ozs., dis- Bolved in 1\ jiiiits of watcir ; add a solution of 1 oz. acetate of lead in sann! (piantity of water. Articles to be colon-dare placed in th(! mixtur<', which is then gradually heated to boiling. Tin- effect of the solution is to make iron ri-srinhle l)lu(^ steel; zinc beconii'S brfuize, and cop|)er or brass beconii's successively y(;l- lowish-red, scarlet, deep blue, bluish-white, and finally white
PRACTICAL TECHNOLOGY. 143
with a tinge of rose. The solution has no effect on lead or tin. By replacing the acetate of lead in the solution with sulphate of copper, brass becomes of a fine rosy tint, then green, and finally of an iridescent brown color. Zinc does not cover in this solution"; but if boiled iu a solution containing both lead and copper, it be comes covered with a black crust, which may be improved by a thin coating ot wax.
Columns, Strength of hollow. — The hollow cylinder is the strongest form of section under compressive force. The experi- ments by which this was proved were conducted upon hollow tapering columns of cast-iron, upon cross-sections, as used in the connecting-rods of steam-engines, and upon forms in which the metal was cast in the shape of the letter H. All these forms proved considerably weaker than the hollow cylinder of equal weight of metal. As the relative merits of these forms of cast- ing metal are of constant use, we append their proportionate strengths: Hollow cylindrical pillar, 100; H -shaped pillar, 75 ; + -shaped pillar, 44. The examples w-ere all of the same weight and length, with rounded ends. General Morin's rule for the thickness of cast-iron pillars may be relied upon, as it is based upon the founder's experience of the minimum thickness. Height, feet, 7 to 10, 10 to 13, 13 to 20, 20 to 27.; minimum thickness, inch, 0.5 0.6 0.8 1.0
Another rule is to make the thickness in no case less than ^ of the diameter. Cellular or tubular girders exemplify to a still greater degree the value of hollow construction.
Copper and Brass, Coating, with zinc. — Dip the articles into a boiling concentrated solution of sal-ammoniac containing finely- divided zinc.
Copper-welding. — A good welding mixture is composed of phosphate of soda 358 parts, boracic acid 124 parts.
Crucibles. — The best crucibles are composed of the following compositions, which are of two kinds — namely, with and without plumbago. 3 parts by measure of the Stourbridge best crucible clay, 2 parts cement, consisting of old used-up fire-bricks, and 1 part hard coke. These ingredients must be ground and sifted through a ^ in. mesh sieve ; the sieve must not be finer, other- wise the pot will crack. This composition must be mixed with sufficient clean cold water, trodden with the bare foot to the con- sistency of stiff dough and allowed to stand for 3 or 4 days, well covered with damp cloths, to admit of its sweating and the parti- cles of clay becoming thoroughly matured. It is then ready for use, and must be blocked by hand on a machine. Owing to the coarseness of this composition, the pot can not w^ell be thrown on the potter's wheel ; and in no instance can it be made by press- ing. The cruciljle must not be burnt in a kiln, but merely highly and thoroughly dried before being placed iu the furnace for use. For brass and copper melting, it will stand one good hard day's work ; but care must be taken to replace the pot again in the furnace after the metal has been poured. If the pot be not al- lowed to go cold, it will last for several days. It will, with the greatest safety, stand one melting of wrought-iron. The cost, when made on the steel manufacturer's own premises, is about
144 PRACTICAL TECHNOLOGY.
forty cents per pot, each pot holding from 100 to 120 pounds of metal. Good Hessian crucibles are composed of 2 parts of the best German crucible clay and 5 parts pure fine quartz sand. Tliis composition must be sifted through a ^ in. mesh sieve ; it is then tempered and trodden with the bare foot, as before de- scribed. When ready for use, it is pressed into different sizes of crucibles, which, when thoroughly dry, are placed in the kiln or furnace and burnt hard.
Another cvrnpoKition : 2 parts best Stourbridge crucible clay, 3 parts cement ; sift through a i-iu. sieve ; temper as before de- scribed and block by hand on the machine. When thoroughly dry, it is placed in the kiln and burnt hard. These crucibles are principally used for melting gold and silver, and also for dry analysis. The best and most perfect fire-clay for crucible mak- ing is nearly always found in the pavement of coal. Some of the Pittsburg fire-clays, and those found to exist in the pavements of some of the Pennsylvania coal-mines, are excellent fire-clays. But the various compositions can not be described, as they are as numerous as the different kinds of clay. The Birmingham soft tough ])ot consists of 2 parts of the best Stourbridge crucible clay, 3 jiarts plumbago, and 1 part cement, consisting of old used- up crucibles ground and sifted through a \ in. mesh sieve.
Another componilion : 4 parts of the best Stourl)ridge crucible clay, 3 parts plumbago, 2 parts hard coke, and 1 part cement, consisting of old pots ground and sifted as before. Where old pots can not be had, the above comi)osition must be burnt hard, gn)und, and sifted. The scales or chippings of the insides of gas-retorts are far superior to the best common hard coke. But where scales and chipiiings can not bo had, hard coke is the best substitute. All the ingredients of this composition must be sifted through a \ in. sieve (but not finer), temi)ered, and made as be- fore described. Wlicn thoroughly dry, it is placed in the kiln and annealed, but not burnt hard. This composition makes a pf)t (for melting the hardest metal) which can not be melted at any ))itch of heat, nor can it be crjicked with the most sudden heat- ing and cooling. It is regularly known to stand 14 and IG melt- ings of iron — even wrought-iron. Any steel manufacturer can make tlie pot on his own premises at a cost of !j;1.20 or there- abouts, the pot holding from 100 to 120 lbs. of metal.
Etching upon Stkioi,. — \N'arm the steel, and rub on a coating of white-wax or hard tallow. When hard, nnirk the device through the wax with a shari)-point('d tool ; apply nitric acid, and allow it to stand for a few minutes ; then wash off the acid ihorouglily with water, heat the steel, and rub off the wax with a rag. Tlie device will be found etched on the steel.
(ioi,D .\Ni) Stia'KU, Test for. — A good test for gold or silver is a jiieci) of lunar caustic, fix(!d with a ])ointiMl stick of wood. Slightly Wet the nu'tal to Ix- teste(l, and rub it gently with tin; caustic. If gold r)r silver, the mark will be faint ; l)\it if an in- ferior metal, it will be quite black.
Gi'N-Bakuiii.s, To bronze. — Clean thoroughly, and ai)ply (\^y iiieans of a rag) nitric or sulphuric acid dilutecl with its volume of water.
PRACTICAL TECHNOLOGY. 145
Hardening Pickle. — Spring-water made into a brine strong enough to float an egg, tiien boiled to precipitate the lime, and allowed to cool.
Iron Articles, Brightening. — When taken from the forge or rolls, the articles are placed in dilute sulphuric acid (1 to 20) for an hour ; they are then washed clean in water, dried with saw- dust, dipped for a second or so in nitrous acid, washed and dried as before, and finally rubbed clean.
Iron Rings, Welding, without scaling. — Take iron filings 1000 parts, borax 500 parts, resinous oil of any kind 50 parts, sal-ammoniac 75 parts. Pulverize completely and mix ; heat the rings to a cherry red, powder the parts with the mixture, and join them together.
Iron, Simple fire-plating for. — By rubbing the surface of iron or other metals with soda amalgam, and then pouring over it a concentrated solution of chloride of gold, the gold is taken up by the amalgamated surface, and it is only necessary to drive off the mercury with the heat of a large lamp to obtain a fine gilded sur- face that will bear polishing. By writing or drawing a design on the iron, the drawing will be re-produced in pure gold. Silver and platinum salts are said to act in a similar manner to the gold.
Iron, To gild cast. — The cheapest way is to use bronze or mosaic gold. The castings are first to be heated hotter than the hand can bear, but not so hot as to burn the varnish, and coated with mosaic gold mixed with a small quantity of alcohol varnisli. If the iron is polished, it must be heated previously and rubbed over with a rag dipped in vinegar.
Lead, Determining presence of, in tiu vessels. — The metal to be tested is first touched with nitric acid and then heated, when the acid evaporates. If lead be contained, stannic acid and nitrate of lead remain. Iodide of potassium is then applied, forming yel- low iodide of lead ; while the stannic acid is white. The yellow stain, therefore, indicates lead, the white, tin. .
Jewelry, To restore the lustre of. — Take 1 oz. cyanide potas- sium and dissolve in 3 gills water. Attach the article to be cleansed to a wire hook, immerse and shake in the solution for a second or two, and remove and wash in clean water, then in warm water and soap. Rinse again, dip in spirits of wine, and dry in boxwood sawdust. If the solution is kept, put it in a tightly- corked bottle, and label POISON conspicuously. One caution is necessary : Do not bend over the solution so as to inhale the odor, nor dip the fingers in it ; if one of the articles drops from the hook, better empty the solution into another vessel.
Metal Surfaces, To protect, from moisture. — Inclose them in tight compartments containing lumps of (luicklime.
Minerals and Metals, Hardness and tenacity of. — In mine- ralogy, in which science the hardness is an important characte- ristic, ten bodies are usually taken as points of comparison — the softest being termed 1 and the hardest 10. These are : 1 , talc ; 2, gypsum ; 3, carbonate of lime ; 4, fluor-spar ; 5, phosphate of lime ; 6, felspar ; 7, quartz ; 8, topaz ; 9, corundum ; 10, dia
146 PRACTICAL TECHNOLOGY.
niond. Hence, when scientific works speak of the hardness of a body being 6, 8, 4, etc., reference is made to the relative hard- ness expressed by the list above given.
The tenacity of metals is estimated by the resistance which wires of the same diameter experience when passed at etjual tem- perature through the same hole of a draw-bench. The following table gives the relative tenacity of various metals and alloys : Steel already drawn, 100 ; iron already drawn, 88 ; brass already drawn, 77 ; gold at 0.875, annealed, 73 ; steel annealed, 65 ; cop- per already drawn, 68; silver at 0.750, annealed, 58; silver at 0.875, 54 ; brass annealed, 46 ; iron annealed, 43 ; platinum an- nealed, 38 ; copper annealed, 38 ; fine gold annealed, 37 ; fine silver annealed, 37 ; zinc, 34 ; tin, 11 ; lead, 4.
Plathstum-Bronze. — This is made of nickel 100 parts, tin 10, platinum 1. It is entirely unoxidizable, and especially adapted for cooking-utensils.
Quicksilver, Coating iron with. — Clean the iron first with hy- drochloric acid, then immerse it in a dilute solution of sulphate of copper mixed with a little hydrochloric acid, by means of which it becomes covered with a slightly-adherent layer of cop- ])er. It is then to be brought into a very diluted solution of mer- curial sublimate mixed with a few drops of hydrochloric acid. The article will become covered with a layer of mercury, which can not be removed even by rubl)ing. This is good as a protec- tion from rust.
S.VDIKONS, Finishing. — See that your bufF-wlieels are well- balanced after they an; covered. Let the wheel be covered with tliicli leather before covering with emery. Get as good a surface <m the article as you can from a wheel covered with No. 70 emery. Mix flour of emery with melted beeswax, and stir in till it is thick. When tlie mass is cool, rub it on a newly-covered wheel with No. 80 emery. Then set tlu; wheel running, and hold on a flint to smooth it until the surface is sutlici<'ntly fine to suit.
SiLVKU Orn.^ments, Imitation. — Ordinary i)laster models are covered with a thin coat of mica powder, which perfectly re- ])laces the ordinary metallic substances. The mica ])lates are first cleaned an<l bleai-hed by tire, boiled in hydrochloric acid, and waslicii iiiid dried. 'I'lic material is tlien finely jtowdered, sifted, and mingled witii collodion, which serves as a vehich^ for ai)i)ly- ing tin? com])ound witli a paint-brush. Tlie objects tlius jjrejjar- ed can l)e waslied in water, and are not liable to bti injured by snlphnrettcd a<ids or dust. Tlie collodion adheres perfectly to glass, ])<jrcelain, wood, metal, ur pupii^r iiKirlii'.
Sii.VEH, Producing satin finish on, by sand-blast. — 'i'he follow- ing isthemetiiod adopted at a large silver-idating establishment : Air is coin])ressed by the driving engine of tlx^ works into an or- dinary reservoir, ami tlience distril)utcd tlirongli pipes whicli ex- tend along tlie tront of the workmen's tallies ; and alxivii tlie lat- ter is a sand recejitacle, V-sliaped, from which a stream of sand fallfl, and is met by a downward blast from the jilpe, which cur- rent drives tbe material in a stream throngli a small hole in th(^ table, beiieatli wliich ii rece|itacle to rec-eive tlie sand is ])laced. 'i lie workman, wlio.se fingers are covered with rubber to jirotect
PRACTICAL TECHNOLOGY. 147
them, holds the article in tlie jet and under the table, watching it through a pane of glass let into the top of the latter. The operation is necessarily very rapid, as the article has only to be turned so that the blast strikes the required portions, when the work is completed. The exposure to the jet, even for an instant, would cut through the Britannia, upon which the plating is afterward deposited. By the interposition of rubber screens of suitable shape, against which the sand has no abrading effect, any fancy patterns or letters are easily imprinted on the surface, the latter, of course, being satin-finished, while the spaces protected by the screens are afterward burnished.
Silver, Restoring color to. — This is adapted to treating silver filagree ornaments, rendering them dead white. The process has long Ijeen a trade secret. If any pewter is found in the articles, it should not be attempted. Pound together charcoal 3 parts, and of nitre 1 ; add sufficient water to form a paste. With a camel's-hair brush give the article a thin coat of the mixture, put it in a small annealing-pan, and submit it to the fire until it be- comes red-hot ; then withdraw it from the fire, let it stand a mi- nute, and turn it out into a weak solution of sulphuric acid (1 part acid, 10 parts water) in the boiling-pan. Boil, pour off the acid, rinse ; wash with warm water and soap, using a soft brush ; dip in spirits of wine, and dry in boxwood sawdust. If any spots should srtll remain on the work, anneal it without the mixture, boil out and wash as before. Burnish the parts intended to be bright. Do not use the common American saltpetre. The Eng- lish nitre, although it costs more, is really less expensive, as a smaller quantity goes further and does the work more effectual- ly. Purchase at the wholesale druggists.
Silver, To regain, from broken black-lead crucibles. — Pulve- rize the crucible and digest it in ^nitric acid for several hours. Decant off the clear liquid, and add to it muriatic acid until no further precipitate forms. Allow to settle, and again decant the clear liquid, wash the precipitate several times with clean water, dry, and fuse in a small crucible with a quantity of carbonate of soda.
Slag, Utilization of. Prussian method. — The high furnaces are provided with a continual overflow for the slag, which runs through a narrow gutter formed in the sand into a shallow pit, through which a small stream of water is kept running. By this chilling process the slag assumes the form of a fine gravel. An endless chain at once lifts the slag out of the pit and loads it upon cars. By grinding this material fine in a cement-mill, it is form- ed into an excellent sharp building-saiid ; the great bulk of it, however, is used, without further reducing its grain, for making bricks.
For this purpose it is mixed with one half of its bulk of mor- tar in a trough in which three shafts provided with long blades are revolving. It is then shoveled into the brick-machines, each of which turns out about twenty-five bricks a minute. These bricks are piled up in tlie open air for drying, and are ready for use after about six weeks. They continue to harden on exposure to the air, and are said to possess greater strength than ordinary burnt
148 PRACTICAL TECHNOLOGY.
bricks. They are extensively used for all kinds of buildings, tlieir liglit-gray color producing a very pleasing effect, and the roughness of their surface fitting them particularly well for re- taining a coating of mortar. They can not be used, however, for foundation walls, as by the absorption of moisture their cohesive- ness is impaired.
The most interesting process is the following : As a thin stream of the fluid slag, falling from a narrow gutter, passes the nozzle of the steam-pipe, a jet of steam is blown through it, and by this simple process it is solidified in the form of most delicate fibres, resembling asbestos or spun glass ; and it falls to the ground like a loose mass of grayish wool. This material is an excellent non-conductor of heat, and is used for covering steam-pipes, boil- ers, etc. The sole expenditure in its manufacture is that of the steam, the exact amount of which could not be ascertained. The material is sold for about $5 per cwt. The steam-pipe is about 1^ inches in diameter, and the nozzle is simply a pipe, flat- tened and then curved into a semicircular form, in order to give the most advantageous shape to the steam-jet. The steam used has a pressure of about 50 lbs. per square inch.
Soldering Liquid. — Into hydrochloric acid place as much scrap-zinc as it will dissolve, still leaving a sponge of zinc. Use the mixture for soldering brass-work. To solder cast or wrought iron, add sal-ammoniac ; and for sheet-tin work, omit the sal-am- moniac.
Solder, Jewelers'. — Melt 1 part lead, add 2 parts tin, and throw in a small bit of resin as a flux. This is strong, easily flowing, and white. In soldering flne work, w(»4 the parts to be joined with muriatic acid in which as much zinc has been dissolv- ed as the acid will take up. It is cleaner than the old method of using Venice turpentine or resin.
Solder, Silver. — Put into a clean crucible, silver 2 parts, clean brass 1 part, with a small ])iece of borax. Melt and pour into in- gots. Solder made from coin, as it frecjuently is, often meets with difficulty around the joints, requiring the use of the file to remove! it, while the addition of any of the inferior metals to the Bolder causes it to eat into the article joined by it.
Sthkl and Iron, To clean, from tcmponiry and sliglit rust. — Cocoanut husks are better than wastes and turpentine.
Steel, Ciihome. — This metal is not only one third stronger than any other steel, but can be produced at a small c^ist, from the fact that when worn out, as in a steel-headed rail, it has a market value, as it can be made over again, which is not Mie case with Bessemer or any other cast-st<'cl. It will also weld without borax or flux, and when burnt can be redeemed on the next heat.
Steel, PoLisirED, To bronze. — To 1 pint methylated spirits add 4 ozs. gum shellac and k oz. gum-benzuin ; i)Ut the l)(>ttle in a warm place, shaking it orcuHionaliy. When dissolved and set- tled, decant tlie clear licjuid and keep it for line work. Strain tlie residue tlirough a fine cloth. Take i lb. powdered bronze gre(>n, varying to suit the taste with lanii)bla('k, red ochre, or yellow ochre. Take as mucli varnish and bronze-ixiwder as required, and lay it on the article, wliich must be tlioroughly clean and
PRACTICAL TECHl^OLOGY. 149
slightly warm. Add another coat if necessary. Touch up with gold-powder according to taste, and varnish over all.
Steel, Protecting, from rust. — ParafEne is the best material for polished steel or iron.
Steel Rails, Cutting. — Remarkable results have been obtain- ed with a disk made from a rail-saw and rotated at 3000 revolu- tions per minute. As the disk was 9.6 feet in diameter, the velo- city of its circumference was in the neighborhood of 86,400 feet per minute. Steel rails were cut with astonishing rapidity, and even melted. Millions of sparks were thrown off, but no heating of the disk could be detected after the cutting.
Tin, Crystallization of. — A platinum capsule is covered with an outer coating of parafRne or wax, leaving the bottom only unco- vered. This capsule is set upon a plate of amalgamated zinc in a porcelain capsule. The platinum is then filled completely full of a dilute and not too acid solution of chloride of tin, while the porcelain is filled with water acidulated with ^ of hydrochloric acid, so that its surface comes in contact with the surface of the liquid in the platinum. A feeble electric current is set up, which reduces the salt of tin. The crystals formed after a few days are well developed. They are washed with water and dried quickly.
Tin, Removing, from copper vessels. — Immerse the articles in a solution of blue vitriol.
Tin, Removing, from plates without acid. — Boil the scrap-tin with soda lye in presence of litharge.
Welding Powders for iron and steel. — (1) Iron filings 1000 parts, borax 500, balsam copaiva, or other resinous oil, 50, sal- ammoniac 75. Mix together, heat, and pulverize. Weld at cher- ry-red. (3) Borax 15 parts, sal-ammoniac 2, cyanide of potas- sium 3. These constituents are dissolved in water, and the wa- ter itself afterward evaporated at a low temperature.
Zinc, Black color for. — Clean the surface with sand and sul- phuric acid, and immerse for an instant in a solution of sulphate of nickel and ammonia 4 parts, in water 40 parts, acidulated with sulphuric acid 1 part. Wash and dry. This takes a bronze color on burnishing.
Zinc Labels, Ink for writing on. — (1) Verdigris 1 oz., sal-am- moniac 1 oz., lampblack i oz. , water I pint ; mix well in a mor- tar, and shake before using. Write with a quill. (3) One drachm chloride of platinum dissolved in } pint water.
Zinc, Painting. — Use a mordant of chloride of copper 1 part, nitrate of copper 1, sal-ammoniac 1, dissolved in water 64. Add hydrochloric acid (comrnercial) 1. This brushed over the zinc sheets gives them a deep black color, turning grayish after dry- ing, in from 13 to 34 hours. A coat of oil-color will adhere to this surface and withstand weather excellently.
Zinc-White, To restore. — This may be done by ignition in ai; earthen crucible.
150
PRACTICAL TECHNOLOGY.
SIMPLE IXSTRrMENTS AND THEIR USES.
Balance, Simple spring. — A is a deal stand 13 by 3 inches ; B is a bard-wood block firmly attached to A ; C is a spring; D is an index-pillar ; E is a scale-holder ; F is a small bent piu to hold the spring steady while changing the scale-pan. The
>1M1'LK )1AI..\N<.E.
spring C should be very fine steel wire, bent over so as to form a loop near the index for E to hook into. The index is a slip of card sot out with a fine pen. The scale-pan is of thin letter- paper, circular, and folded like a filter-paper, as indicated by tlie dotted line. With this minute fractions of a grain can be re- cognized.
B.VKO.METER, To make a cheap. — Obtain a straight fine glass tube, about 33 inches long, and with as clean an interior as possi- ble, sealed at one end, and having an even uniform bore of about 2j lines diameter. The mercury to be used irhould be perfectly pure and free from all air and moisture. This latter requisite may be assured by heating the mercury in a ])orcelain dish to nearly tli*; boiling-i)oint, previous to using it. The tube is then held securely, with the ojjen end up])ermost, and carefully filled with the ru|uid metal. The open end of the tube is then securely covered with the linger, the tube inverted, and the end covered hy tht! finger ])luMge(l below the surface of a little mercury placed in a small vessel to receive it. The finger is then removed, when the nuircury in the tube will immediately fall to a h'vel of about 30 ini'hes above the surfac«^ of that in the small reservoir below. In order to attach the scale correctly, it will he necessary to com- pare the indications with those of some good instrument.
BAKOscorK, To make a. — Take any bottle ; pour colored wafer into it, about ', of the (juantity the bottle will lK)ld ; insert in it a glass tub<\ from 3 to 4 feet long, and passing air-tight through the stop]>er, which must also Ix? airtight. Let a paper index, divided according to any scale of division, say into inches and fractions of uu incli, be glued to the glass lube, lilow inio the
PRACTICAL TECHNOLOGY.
151
glass tube so as to cause the water to ascend tlie tube a few inches, say 10 inches, and the instrument is constructed. The bottle must be placed in another vessel, and protected by sawdust, or some other material, from the influence of changes in the tempe- rature of the atmosphere. This very sensitive instrument records faithfully any change in the density of the external air, and the approach of a storm will infallibly be indicated by a sudden rise of the water in the glass tube.
Camera, Wonder, How to make a. — A wonder camera is a sort of magic lantern, so contrived as to enable one to use opaque objects for projection upon the screen instead of glass transparen- cies. For example, if a photograher wishes to show his customer how an enlargement from a carte will look, he simply has to put the carte in the wonder camera, and " throw it up." Many en- largement-scales may be made in this way. It consists of a wooden box, with a top made of tin or sheet-iron ; the chimney is made of the same material. The lens is the same as used upon a camera for making photographs. At the back of the box (as will be seen by reference to the elevation and plan, Figs. 2 and 3) are two doors placed upon hinges.
When the box is in use, the door e is kept closed. The other door consists of two parts placed at right angles to one another ;
Fig. 1.
Fig. 2.
A ■WO'TTDEB CAMERA.
the object of this is to fill the opening in the door e while the pictures are being attached to c ; w^hen c is swung into position opposite, the lens, placed at h d, is carried to one side. If stereo- scopic views are to be shown, a slit may be cut at e, through which they may be inserted with- out opening the box. The door e should be cut off a little at the bottom, so as to admit air. The light is placed at 7^ as nearly oppo- site the picture as possible. It should be a strong light ; an ar- gand burner is the best. At the back of the light is a piece of tin, bent into the form of a reflector. Fig- 3.
The light coming from h strikes c, and is reflected through the lens upon the screen. The plan of the box is represent- ed with the top removed. No dimensions are given, as they will depend upon the focal distance of the lens and height of
152 PRACTICAL TECHNOLOGY.
the light. Care must be used to have the distance from the lens to c when closed equal to the focal distance.
Electrical Machine, A simple. — A B, in the annexed en-
S
A SIMPLE ELECTRICAL MACHINE.
graving, is a glass tube fixed at one end in a wooden handle. The rubber, with its flap, D, carries a little Leyden jar, the end of which is visible at F. This jar is coated inside and out with a resinous insulating compound, and the metallic lining of the inside of the jar is in contact with the brass collecting- ring, E. The handle being held in one hand and the rubber in the other, when the tube is rubbed the little ring and jar rapidly- collect electricity. A i inch spark and smart shock may be readily obtiiined from this apparatus, the length of the spark depending upon the amount of rubbing each time before the jar is dis- charged. When it is not desired to take the shock through the human body, the jar may be discliarged by means of the metallic cord, H.
Electuical Orrery, to accompany the above machine. — This is represented below. It is balanced on a pivot at F. The
ELECTRICAL ORRERY,
light hollow brass ball. A, represents the sun, and pith balls, B and D, the earth and moon, rotating about the pivot E. The metallic i)oints jn'ojecting troni H and 1) (in opposite directions, of course) cause thfse to rotati- round each other ; but the lever- age of the ])oint I) b(!ing, from its position, greater than the leverage of B, it sets the long arm of the orrery in rotation uj)on tlu' pivot F.
(J.m.vanometku, To make a 8imi)le. — Take an ordinary pocket- coMipasB and wind 100 feet of No. 18 insulated copper wire iiroimd it.
Kai.kidoscopk, To make a. — Take two strips of glass, 8 or 10 in. long, 1 to \\ in. l)road at one end and nbout \ as l)r<)ad at the oth(!r. Hhu-ken one side; of each witli black varnish. Put two HMiootli straight edges together, and form a hinge by gluing a strip of clotli over tlir two edges. Make the angle between the
PRACTICAL TECHNOLOGY. 153
Strips of glass an aliquot part of 180% as 20°, SO*', or 45°. Cover the open side of the triangular prism with black velvet. Place in a tin or pasteboard tube so that the angle of the smaller end of prism is nearly in the centre. Cover top of tube with clear glass, and cover this with paper, except a small hole in centre. In bot- tom of tube, form a cell by placing two pieces of glass i in. apart (the lower one of ground glass). In this cell place fragments of broken colored glass, beads, etc. They must be capable of free movement in the cell when the tube is turned in the hand.
Leyden Jar, To make a cheap.— Line a thin glass candy-jar inside and outside with tin-foil, such as is used to wrap chew- ing-tobacco in. Stick the foil, on with mucilage, varnish, or flour paste. A still cheaper plan is simply to fill a glass jar nearly full of water, and place it within another vessel of water, so that the water, both outside and inside, shall be on the same level.
Magic-Lantern Slides, Painting. Four methods. — (1) Use transparent colors, like Prussian blue, gamboge, and carmine. These will give the three primary colors, and by their mixture, the other tints. Apply witli a brush, and a transparent drying varnish, like dammar varnish. Allow one coat to dry before ap- plying a second. Considerable aid can be derived from stippling, the color being strengthened, where necessary, by applying it with the point of a fine brush. The colors must not be used too thin. (2) Flow the glass plate with albumen, after the manner of photographers, and paint with aniline colors. This process gives great softness and brilliancy to the pictures, but they are apt to fade. (;J) Paint with water-colors, and then flow the entire surface with Canada balsam, covering the painted side with a glass plate. (4) Use water- colors, but mix them with turpentine instead of water, and work rapidly.
Meridian, To find the.— Mr. George W. Blunt says : _" Take a piece of board, or any similar material, and describe on it a num- ber of concentric circles. Place this in the sun ; over the centre hang a plummet. Observe the shortest shadow from the plum- met ; the sun will then be on the meridian ; draw a line to the centre of the circle, and that will be the true meridian-line. This will do to mark the apparent time, or to correct the compass for variation."
Mirrors, Globe, To make. — Melt together 1 oz. clean lead and 1 oz. of fine tin in a clean iron ladle ; then immediately add 1 oz. Insmuth. Skim off the dross, remove the ladle from the -fire, and before it sets add 10 ozs. quicksilver ; now stir the whole care- fully together, taking care not to breathe over it, as the fumes of mercury are very pernicious. Pour this through an earthen pipe into the glass globe, which turn repeatedly around.
Pipes, Determining proportions of. — The instrument consists simply of a piece of wood shaped like a set- square, as shown in Fig. 1, or a diagram of the same form drawn on paper, and di- vided out along the two edges, which are at right angles to each other, the divisions being taken to represent inches, feet, or yards, etc., according to the kind of work for which the instrument is used. Suppose that two pipes, A and B, Fig. 2, respectively 5 iu.
154
PRACTICAL TECHNOLOGY.
and U in. in diameter, deliver into a third pipe, D, and it be re- quired to find the proper diameter fortlie latter pipe. Then from 5 on the scale of one of the divided edges to 4^ on the other.
FIG.I
APPARATUS FOR DETERMINING THE DLAMETER OP PIPE8.
draw a line, as shown dotted in Fig. 1, and the length of this line measured with tlif^ saiiu^ scale as that to which the edges are divided, will be the diameter of pipe re(iuin'(l ; in this case, 6 J in. On the other hand, if a pipe, D, GJ in. in diameter, be deliver- ed into a pipe. A, 5 in. in diameter, and it was required to know what other size of pipe, B, could also be 8up])lie(l, all that would bo necessary woiilil l)e to take the division ])oiMt 5 on one edge as a centre, and, with (Ji{ in. as a radius, describe an arc cutting the other divided edge. The point at which tlm latter edg(( was cut by this arc would show the diameter of ])ipe required.
Hifi-k-Tki,ks('OPK, To make a. — Object-glass should belialf an in. in diameter, focus 24 in., or as long as convenient. Kye-])iece may be a single lens of low ])()\ver with cross spider lines fixed in its focus. The target will then appear invc^rted. The lenses are inch)S(;d in a l>rass tube with a hiiigoor ball joint at the breech or eye-piece end, and slides at tlie muzzle, to depress tln^ ol)ject glass for increased elevation. 'i"he two ]>(iints of attachment to the bar- rel are the same as for ordinary fore-and-leaf sights.
TELKHCorE, To make a cheap. — A correspondent says: " 1 ee-
PRACTICAL TECHNOLOGY. 155
lected a meniscus 1 in. in diameter and of 48-iu. focus. This was for my object-glass. I bad already in my possession a two-lensed double-convex jeweler's eye-glass ; one of tbese lenses was used for the eye-piece, its focal leugtb being a trifle over 1 in. The tube was made of pine-wood. A piece of straight, evenly-grained one-in. pine board, 2 in. wide and 8 feet long, was cut in the mid- dle, and the two pieces, after making a tapering semicircular groove in eacli, well glued together. This done, the next thing was to give it a round, tapering form, 2 in. in diameter at one end, and a trifle over an iucli at the other. This was done with a com- mon carpenter's plane. I now had a tube 4 feet long, with a ta- pering bole througb its length, and 1^ in. in diameter at its larg- est end. Two wooden cells for the lenses were then turned in a lathe, and were made to go on to tbe tube, as does the cover of a wooden pill-box. A round bole, the size of the lens, was made in each, the meniscus being contracted to f in., and the e_ye-glas3 to ^ in. diameter. The piece carrying the eye-glass Avas made so as to slide some distance on the tube, for adjustment to distinct vision. The tube was painted and varnished, and mounted equa- torially ; and it proved to be a good instrument, showing Jupiter's moons, their movements and eclipses, handsomely, the ring of Saturn, the horned appearance of Venus, the mountains and cra- ters on the moon, the spots on the sun, etc. Several of the nebu- lae were also visible, especially those in Andromeda, Orion, Her- cidea, and Sagittarins. The whole need not cost over two dollars, beside the time in making, provided one is a mechanic.
" The meniscus (concave on one side and convex on the other) is the proper form for a single-lens object-glass, and a plano-con- vex lens makes the best form for the eye-piece. Care must be taken to so set the lenses in their cells that their foci will meet centrally. When this is the case, the lenses are said to be well centred, and in that way we get rid of most of the prismatic color. Another point that wants attention is the mounting. Ab- solute steadiness is required for close observation. I used to put mine upon a post set firmly in the ground. The equatorial ar- rangement for mounting is described in nearly every work on telescopes."
Thermometers, Hard-rubber. — This instrument has been made by riveting the rubber to a thin strip of steel, about a foot in length and J in. in width. The bottom of this was held fast, while the top was free to move, and so to indicate the temperature on a graduated arc. This one, now in use, has a range from zero to 90° Fahr., and is as sensitive as the common mercurial thermo- meter. It is well adapted for the ordinary range of the atmo- sphere, but is not suitable for indicating high degrees of heat, as the rubber softens at about 200° Fahr. Another thermometer was made by perforating a thin strip of steel, at intervals of an inch, and placing upon it a strip of rubber compound when in a plastic state. This was coiled, with an intermediate strip of me- tal, which forced the rubber through the holes It was then vul- canized in the usual manner ; and when cold, the intermediate strip was withdrawn, leaving an open space between the coils. Tills saved the trouble of riveting, and gave to the rubber an un- broken and smooth surface. The coil is held last at the centre,
156 PRACTICAL TECHNOLOGY.
and the outer end is left free to move. Another thermometer was made of glass and hard rubber, the latter in the form of an arc, being riveted at both of its ends to a glass plate, which formed the chord.
Thermometers. — To change Fahrenheit degrees into Centi-
_, ^ 5 (F.-33) ^, . ^ . .^ , , . „ 9 C. . „„
grade: C.= . Centigrade mto Fahrenheit: F.=—- — ^ 32.
y 5
9R.
Reaumur into Fahrenheit : F.= '-I- 32. Fahrenheit into
4 '
Keaumur : K. = • Keaumur into Centigrade : C. = — — •
4C. Centigrade into Reaumur : R.=-r-
0
RECIPES FOR THE PREPARATION OF WOOD.
Dyeing Woods. — All light woods may be died by immersion. A fine crimson is made as follows : Take 1 lb. ground Brazil, boil in 3 quarts of water, add ^ oz. cochineal, and boil another half hour ; may be improved l)y washing the wood previously with ^ oz. saffron to 1 quart water. The wood should be pear wood or sycamore. Purple satin : 1 lb. logwood chips, soak in 3 quarts of water, boil well an hour ; add 4 ozs. pearlash, 2 ozs. powdered indigo. Black may be produced by copperas and nutgalls, or by japanning with two coats of black japan, after which varnish or polish, or use size and lanii)l)l!ick j)r<!vions to laying on ja- pan. A blue stain : 1 lb. oil of vitriol put in a glass bottle with 4 ozs. indigo ; lay on the same as black. A lino green : 3 pints of the strongest vinegar, 4 ozs. best powdered verdigris (poison), ^ oz. sap-green, ^ oz. indigo. A bright yellow may be stained with aloe ; the whole may be varnished or i)olishcd.
F^iJONY, Artificial. — Treat sea-weed for 2 hours in dilute sul- l)]iuric acid. Of the charcoal thus obtained taki^ 16 parts ; dry, and grind it. Add licjuid glue 10 parts, giitta-])erclia 5, india-rub- ber 2J-, the last two dissolved in naphtha, 'i'hen add coal-tar 10, ))ulverized Hulphiii- 5, piilveriz(>d alum 2, j)ow(len'(l resin 5, and iieat tlic! mixture to 300' Fahr. This when hard will take a pol- isli equal to ebony, and is the same in color and liardnesa.
Oak, To color orange-ycdlow. — Wuh thv. wood with a mixture of tallow 3 ozs., wax !j oz., and turpfnlinc 1 pint, mixed by heat- ing together and stirring. A])i)ly in a warm room until n dull polish is aci|uin(|. Thi-n coat, after an lK)ur, with thin polish, and repeat until the dcsiicd depth and brilliancy of tone is obtained.
ScKKWs, WoitiiK.N, To season. — Bore a liole longitudinally through tlm centre of the scniw ; it will not In- ii\>i to crMck so badly in seasoning, l)ecause then the air can g«it to tlie centre of the wood, tiie sap t scapes therefrom, the centre of the wood con-
PRACTICAL TECHNOLOGY. 157
tracts, and tlie strain on the outside is lessened. Of course, the larger the hole.the better for the seasoning process ; but it should not, and need not, be large enough to materially weaken the screw. If, in addition, you can boil the screw in water, the job will be bettered ; if boiled in oil, it will be complete.
Veneers, Artificial, To make. — Soak the wood for 24 hours, »and boil for ^ liour in a 10 per cent solution of caustic soda. Then wash out the alkali, when the wood will be elastic, leather-like, and ready to absorb the desired color. After immersion in the color-bath, dry between sheets of papex under sufficient pressure to preserve the shape.
Veneers, Steaming. — Blocks of wood intended for veneers may be steamed in a solution of borax and ammonia. They will then become soft and easy to cut, and, beside, will retain their flexibility for a long time.
Wood, A liquid. — Sawdust can be converted into a liquid wood, and afterward into a solid, flexible, and almost indestruc- tible mass, which, when incorporated with animal matter, rolled, and dried, can be used for the most delicate impressions, as well as for the formation of solid and durable articles, in the following manner : Immerse the dust of any kind of wood in diluted sul- phuric acid, sufficiently strong to affect the fibres, for some days ; the finer parts are then passed through a sieve, well stirred, and allowed to settle. Drain the liquid from the sediment, and mix the latter with a proportionate quantity of animal offal, similar to that used for glue. Roll the mass, pack it in moulds, and al- low it'to dry.
Wooden Labels, Preservation of. — Thoroughly soak the pieces of wood in a strong solution of sulphate of iron ; then lay them, after they are dry, in lime-water. This causes the formation of sulphate of lime, a very insoluble salt, in the wood. The rapid destruction of the labels by the weather is thus prevented. Bast, mats, twine, and other substances used in tying or covering up trees and plants, when treated in the same manner are similarly preserved. Wooden labels, thus treated, have been constantly ex- posed to the weather during two years without being affected thereby.
Wooden Taps, Preserving, for Casks. — The articles should be plunged in paraffine, heated to about 248° Fahr. until no air-bub- bles rise to the surface of the melted material. They are then al- lowed to cool, and the paraffine is removed from the surface, when nearly congealed, by thorough rubbing. Ta[)S thus treated will never split or become impregnated with the liquid, and may be used in casks containing alcoholic liquors.
Wood, Brown stain for. — Paint the wood over with a solution made by boiliug 1 pint catechu (cutch or gambler) with 30 pints water and a little soda. Dry, and then paint over with a solution of bichromate of potash 1 pint, water 30 pints. By a little dif ference in the mode of treatment, and by varying the strength of the solutions, various shades of color may be given to these materials. The colors will be permanent, and will tend to pre- serve the wood.
158 PRACTICAL TECHNOLOGY.
Wood, Preserving. — This process is valuable for rail way-slei.p- ers. Steam the timber, and inject a solution of silicate of soda for 8 hours. Then soak the wood for the same period in lime- water. (Dr. Feuchtwauger's process.)
Wood, Preservative ])reparation for. — Mix 40 parts chalk, 50 resin, 4 linseed-oil, melting them tt)gether in an iron pot ; then add 1 part of native oxide of copper, and afterward 1 part of sulphuric acid. Apply with a brush. When dry, this varnish* is as hard as stone.
Wood, To ebonize. — Collect lampblack from a lamp or candle on a piece of slate. Scrape off the deposit, mix with French polish, and apply to the object in the ordinary way.
Wood, To fire-proof. — Paint twice over with a hot saturated solution of 1 part green vitriol and 3 parts alum. After drying, paint again with a weak solution of green vitriol in which pipe- clay has been mixed to the consistence of paint.
THE PREPARATION AND PRESERVATION OF NATURAL-HISTORY SPECIMENS.
Anatomical Specimens, Preserving. — Glycerine will preserve the natural colors of marine animals kept immer.<od in it.
BiKDS, Stuffing. — The following tools are required (see Fig. 1). — First, there is the scalpel. This can be purchased for a small sum from any maker of surgeon's instruments. The blade is short and very .sharp, while the handle (not jointed) is long enough to allow of a firm grasp. From the same maker, a couple of jiairs of surgeon's scissors should also be obtained, one quite small and sharp -pointed, the oth(>r of medium size ; also two or three spring forceps of various dimensions. A small pair of pliers for clip])ing wire is required, some 8])ools of cotton (Xos. 10, ;}0, and 100), a quantity of excelsior and tow, some cot- ton batting, a little i)re]>iire(l glue, a number of jjieces of wire about fifteen inclies long, and straight (.size No. 20 or there- abouts), a box of dry oatmeal, and some ar.senical soap. This last can generally l)e obtained of druggists, or, if not, can be mad<! of carl)onatc of pota.sh '.] ounces, white arsenic, white soap, and air-slaked lime, 1 ounce each, and jiowdered camphor, -?g of an ounce, 'i'liis is combined into a thick ])aste with water, and ai)])lied us below descriWeii, with a small paint-brush. It should be nuirked as poison, and kept scruimlously out of the reiicli of children or pet animals.
If th(! i)inl has been shot, immediately afterward all the holes made in its hody, as well as the mouth, sliould l)e plugged with cotton, in order to prevent the escape of blood or lupiids. Opera- tions should not lie begun for twenty four liours, so that the l)ody may havt; ample time t(» .stilleu and the blood to coagulate. It is
PRACTICAL TECHNOLOGY.
159
well during this period to inclose the bird, head downward, in a cone of paper, so that the feathers will be held smooth.
The first process is skinning. In commencing, the left hand is used to part the feathers, exposing the skin from the apex of the breast-bone to the tail. With the scalpel held like a pen, a free incision is made between these points, care beinpf taken to divide the skin only, without cutting into the flesh. The skin is then pressed apart, and oatmeal dusted into the cut, in order to absorb any fluids which may escape. Careful lifting of the skin clear of the flesh follows, until the leg is reached, when the scalpel is again used to disarticulate the thigh-joints. The bone of each thigh is then exposed for its whole length, by pushing back the skin, and the meat removed, when the bone is replaced, and the other thigh treated in similar manner.
PIG. 1.— TAXIDERMICAL IJIPLEMENTS.
The skin is next detached, to the wings, which are cut from the body at the joint next the same, and the bones scraped clear of meat. Then the neck is divided, so that the skin, with the head attached, can be peeled from the entire body clear to the root of the tail. The last is bent toward the back with the left hand, the finger and thumb keeping down the detached parts of the skin on each side of the vent. A deep cut is then made across the latter until the back-bone, near the oil-gland at the root of the tail, is exposed. Sever tlie back-bone at the joint. This detaches the body, which may be removed and thrown aside, while the root of the tail, with the oil-gland, is left. Great care is needed in this operation, as, if not enough bone be left at
160
PBACTICAL TECHNOLOGY.
its root, the tail will come out ; but all fleshy matter should be neatly dissected away.
The neck need not be split or in any wise cut. The skin is merely pulled over the flesh, as a glove is removed from the finger, until the skull is exposed and appears as in the sketch, Fiji. 2. With the point of the knife, remove the ears ; and on reaching the eyes, carefully separate the lids from the eyeballs, cutting neither. It requires very delicate and slow work at this point, so as not to injure the eyelids. Then scrape out the eye cavities, and cut away the flesh of the neck, removing: at the same time a small portion of the base of the skull. Through the cavity thus made extract the tongue and brains, and after cleaning away all fleshy matter, paint the eye orbits with arseni-
FIO. 2. — MODK OK ATTACmNci THE FALSE BODT
ciil soap, and stuff them tightly with cotton. Care should be taken not to detach the skin from the l)ill, as it is necerisary to leiivr- the skull in ))lace. Finally, fill the interior of the skull wiili tow (never with cotton), aft(^r coating internally with the. j)repiired soap.
Tlie skinning operation being now c()m])lcted, the stuffing is next proceeded witli. To pnipare for this, the bird, before being skinned, sliould liave been measured, first as to its girth about the liody, and second as to its h;ngth from root of tail to top of skull, following tile sliajjc of" tlu^ form. From these data an arti- ficial hody of the right dimensions is constructed and inserted as follows: On a piece of straight wire, e<|ual in length to the la,st uieasurement above jur-ntioned, a hunch of exc(dsior is secured
PRACTICAL TECHNOLOGY.
161
bv repeated -windinof with stout thread. This bundle, which is represented iu our Fig. 2, is moulded to a shape resembling that of the bird's body, and its girth is regulated by the similar measurement already obtained from the bird itself. As will be seen, it is attached at the end of the wire, the long protruding portion of which serves as a foundation for the neck. The ex- tremity of the wire is clipped by the pliers to a sharp point, and then forced diagonally upward through the skull, on top of which it is clinched flat. Cotton batting is then wound about the wire between skull and body, until sufficient thickness is obtain- ed to fill the skin of the neck. The position of the various parts at this point is represented in Fig. 2. Painting the inside of the skin with arsenical soap follows, and then the skin is drawn back so as to envelop the false body, and a needle and thread are thrust through the nostrils to make a loop for convenience in haudlinor.
FIG. 3. — STUFFING THE LEGS.
The finest pair of forceps is employed to pull the eyelid skin into place, to arrange the feathers, and to pull up the cotton in the orbits so as to stuff the cavities out plumply. More cotton is next pushed down the throat until the same is entirely filled. Two pieces of wire — quite stout for large bird— are then sharp- ened at one extremity. Taking the wire in one hand and guid- ing it with the other, the operator shoves it into the leg, from the ball of the foot up alongside the thigh bone, the skin being turned back for the purpose. Cotton is then wound about both wire and bone, in order to fill the thigh out naturally, and the same process is repeated for the other side. The ends of the wire below are left protruding in order to support the bird on a perch, if such be desired. The upper ends are pushed clean through the artificial body, from below up, and clinched on the
162
PRACTICAL, TECHNOLOGY.
upper side. This secures the legs, which are afterward bent in natural position (Fig. 3). The bird can now be set up — that is, the wires stretching out below the claws can be wound about a perch or pushed through holes in a board and clinched on the under side. In the latter case, it will be necessary to spread the claws and fasten them with pins. For small birds, the cut in the bi-east need not be sewn uj) ; a chicken or larger fowl will require a few stitches to hold the edges together. If the tail feathers are to be spread, a wire is thrust across the body and throuorh each feather, holding all in the proper position. The wings are then gathered closely into the body, and two wires.
no. 4. — 'llli: I'.IKl) l-KKCAKKI) FOle DllYINO.
one from each side, are ])iishc(I in diagonally from ui>, down, and through the skin of tlu' second joint (Fig. 4). The wings are tliiis held, and tln' wires, as Wfll as tliat tliiougli the tail, are left protruiling for an inch or more. A tnuchof glue within the eycv lidH ])rej)areH the latter for the eyes. These must hi? purchased from taxidermists, but for small birds <'ommon bla<'k beads will aiis\v<;r. If plain glass beads can lie nhtaincid, by the aid of a little piiint the student can easily imitate the ey(' of a diickeii. .After tli(! eyes ai'e insertcMl, a sliai|) needle is used to pull the lids around them and into pliKe.
'{"he <)|i(?rator must now, with a line pair of f(»rceps, carefully
PRACTICAL TECHNOLOGY. 163
adjust the feathers, smoothing them down with a large camel's- hair brush. This done, thread must be wound over the body very loosely, beginning at the head, and continuing until all the feathers are securely bound. The bird is then left to dry for a day or two, when the thread is removed, the ends of wire cut oif close to the body, and the work is complete.
Entomological Specimens, To preserve, from insect ravages. — Place crystals of carbolic acid throughout the cabinets, and the evaporation of the crystals will keep them thoroughly saturated with carbolic acid vapors, which will kill all living insects therein.
Fish, To mount and preserve. — It is impossible to preserve the iridescent tints ot the living specimens ; but before proceed- ing to the operation of skinning, it may be stated that the scales, as well as their color, may be preserved to a certain de- gree by applying tissue-paper to them, which, from the natural glutinous matter which covers the scales, will adhere firmly ; this being allowed to remain until the skin has dried, may easily l)e removed by moistening with a damp cloth. All small fish should be mounted in section, while the larger varieties may be preserved entire. Supposing the fish to be of such a size as to be mounted in section, first it is necessary that it be as fresh as possible, as the scales will become detached if decay set in. Place the fish on one side, and cover the side uppermost with tissue-paper, as above stated ; also extend the fins by means of the same, and allow them to remain a few moments until fixed and dry. Haviug provided yourself with a damp cloth, spread it smoothly upon tlie table, and place the fish upon it, papered side down. With the dissecting scissors, cut the skin along an oval line, following the contour of the body, but a little below the ex- treme dorsal edge and a little above the ventral one, and remove the skin included within this line. The remaining skin must now be detached from the flesh, beginning at the head and separating it downward toward the tail. The spine must be severed close to the head, and also at the tail, and the entire body removed. All the flesh having been taken from the skin, and the eyes removed, the inside must be wiped out and the preservative (arsenical soap) applied. The skin should now be filled with tow, very evenly placed. When filled, it should be laid, with the open side down, upon a board of proper dimensions, and fastened to it by small tacks, beginning at the head and fastening the edges downward toward the tail. It should then be set aside to dry. The paper is, after drying, removed, and eyes of wood (painted to the proper colors, and not varnished) are inserted with a little putty. Finally the skin should receive a coat of colorless varnish, when the specimen is ready for the cabinet.
Sea-Weed, Preserving specimens of. — The best time to col- lect is when the tide has just commenced to flow, after the low- est ebb, as the sea weeds are then floated in, in good condition. All specimens should be either red, green, purple, black, or olive ; no others are worth preservation.
Mounting is done by immersing a piece of paper just below the surface of the water, and supporting it by the left hand ; the weed is then placed on the paper and kept in its place by the
164 PRACTICAL TECHIVOLOGY.
left tliumb, while the right hand is employed in spreading out the branches with a bone knitting-needle or a camel's-hair pen- cil. If the branches are too numerous, which will be readily ascertained by lifting the specimen out of the water for a mo- ment, pruning should be freely resorted to, by cutting off erect and alternate branches, by means of a sharp-pointed pair of scis- sors, close to their junction with the main stem. When the specimen is laid out, the paper should be raised gradually in a slightly sloping direction, care being taken to prevent the branches from running together. The delicate species are much improved in appearance by reimmersing their extremities before entirely withdrawing them from the water. The papers should then be laid Hat upon coarse bibulous paper, only long enough to absorb superfluous moisture. If placed in an oblique direction, the branches are liable to run together. They should be then removed and placed upon a sheet of thick white blotting-paper, and a piece of washed and j^ressed calico placed over each speci- men, and then another layer of thin blotting-paper above the calico. Several of these layers are pressed in the ordinary way, light pressure only being used at first. The papers, but not the calico, may be removed in six hours, and afterward changed every 24 hours until dry. If the calico be not washed, it fre- quently adheres to the algiP, and if the calico be wrinkled it pro- duces corresponding marks on the paper. The most convenient sizes of paper to use are those made by cutting a sheet of paper, of demy size, into 16, 13, or 4 equal pieces. Ordinary drawing- paper answers the pur]iose very well. For the herbarium, each species should be mounted on a separate sheet of demy or cart- ridge size. Toned paper shows off the specimens well, a neutral tint answering best for the olive, pink for the red, and green for the green series.
Skins of Small Animals, Dyeing. — The green hull of the European walnut is turned to account in Euro])e for dyeing furs black, and the hull of (lur black walnut could probably be simi- larly emi)loyed. The walnut hull is crushed and the juice squeezed out from the ])ulp, with the addition of a little water. A small (juantity of lime is added, and the dye is ready for use. The color is extremely difficult of extraction, and attaches itself very readily to any kind of hair, and it is used extensively as a hair-dye.
Sti'FFIN*; small Quadtutpeds. — Begin by making a longi- tudinal incision between the hind legs, extending (juite back to tlie vent, the hair having been carefully i)artcd so that it may not be cut. Do not cut into the abdominal cavity. The skin can now be separated from the flesh and turned back as far as the tliigli, whicli is sfvircd at the joint. When this is done on botli sides, tliir gut should bo drawn out and severed at a short (lisiance from tlie vent. The tail should also l)e disjointed at the root. Tills being done, the skin can be loosened around the body until the fore-legs are reached, when they also should be dissevered. Tlie skinning now proceeds along the neck until t!ie skull is reiiched. Here <-nnsiderable care is necessary to re- move the skin without damage to the ears, eyelids, and lii)H.
PRACTICAL TECHNOLOGY.
165
The skin is left attached to tlie skull ; when the operation has proceeded far enough to expose the muscles of the jaws, the skin must be separated from the body at the first joint of the neck. The tongue, eyes, and muscles, remaining attaclied to the head, are now to be carefully removed, and the brain taken out from an opening in the back of the skull cut through for that purpose. To make this opening, amateurs can use a small gimlet or bit with very small animals, and a large one as cir- cumstances may demand. The legs are now to be skinned out quite down to the claws, which completes the o^jeration of skin- ning. During tlie entire process, all fluids escaping must be im- mediately soaked up with cotton. As soon as the skin is re- moved, it should be thoroughly rubbed with arsenical soap, not omitting the inside of the skull and mouth cavities.
The following explanation of stuffing relates to a small ani- mal such as the squirrel. Provide yourself with cotton, tliread, and twine, also stuffing-forceps, a pair of pincers, a file, and •wire-cutters. With the aid of the forceps (a pair of slender- jawed pliers), supply the various muscles of the face and head by inserting cotton both through the mouth and eyelids. Take annealed iron wire and cut off 6 pieces : No. 1, two or three inches longer than the total length of the body ; Xos. 2 and 3 for the fore-legs ; Kos. 4 and 5 for the hind-legs ; each of these should be three inches longer than the limbs they are to support ; No. 6, for a support for the tail, of the same propor- tionate length as the others. With a large pair of scissors, cut fine a c[uannty of tow, and with this, by the use of the long forceps, stuff the neck to its natural dimensions. Taking wire No. 1, bend it in four small rings, the distance between the two outer representing the length of the body taken from the skin, a, leaving one long end for a support to the head and neck, b (see
STUFFING ANIMALS.
figure). Mould tow about that part containing the rings, and, by winding it down with thread, form an artificial body. Sharpen the projecting end of the wire to a fine point with the file, and insert it up through the tow in the neck, and thence through the skull ; the skin should then be pulled over the body. Wires No. 2 and 3 are placed next in position by insert- ing them through the soles of the feet, up within the skin of the leg, and through the body of tow, until they appear upon the opposite side. With the pincers, bend over the end of each, forming a hook ; the wires must then be pulled backward, thus fastening the hooks firmly into the body. The loose skin of the limbs should then be stuffed with cut tow, taking care to imitate the muscles of the living subject. Nos. 4 and 5 can be fixed in position after the same manner, unless the animal is to rest en-
loG PRACTICAL TKCUNOLOGY.
tirely upon its rear (as in tlie case with the squirrel feeding) ; then the wire must be inserted at the tarsal joint instead of at the sole of tlie foot. If any depressions appear in the skin, they must be stuffed out witli cut tow. Wire No. C should now be inserted at the tip of tlie tail, and forced down within the skin, hooking it into the body in the same manner as the leg-wires. Stuff the tail to its proper dimensions with cut tow, and care- fully sew up the incision along the abdomen. Having i)repared a board about f inch thick, pierce in it two holes at the proper distance apart for the reception of the wires (four holes will be needed if the animal is to stand on all extremities) ; these must be drawn through upon the under side until the feet rest close upon the upper surface, when they should be clinched. The different joints of the limbs can now be imitated by bending the wire at the jiroijor i)oints. The eyes should next be placed in position, and cemented in the orbits by a little putty. Care should be taken in arranging the eyelid, for the expression de- pends altogether upon this point. Clip off any superfluous wire which may extend above the head with the wire-cutters. The specimen should be placi^d In some locality free from moisture, and allowed to dry thoroughly, when it is complete for the cabi- net.
PAINTING, GILDING, AND VARNISHING RE- CIPES.
Baij-OON Varnishes. — Mr. John Wise, the well-known aero- naut, says : " There are two ways of preparing linseed-oil for bal- loon varnish : llu; (juick and the slow process. The first is by heating the oil up to a temju'rature at which it will ignite spon- taneously. In order to secure it from burning up, it must be lieated in an iron or copper vessel, witli a lid that can be closed when it begins to omit dense white vapcir. If it is desired to have it fast drying, from 4 to G ozs. litharge per gallon should be boiled in it. Tliis process takes about one hour, ami renilers the oil thick and tougli, giving a good body and glossy surface to theclolh. The slow jjtoccss is to bi)il tlu- oil from 12to 20 hours, keeping it at a temperature of alxiut 200 Fahr., incorporating witli it, while boiling, i oz. suljdiate of manganese to each gal- lon of oil. These varnishes should l)e api)H(d to the cloth tole- rably hot. Tln're are other formulas, sucli as the incorporation with the oil of snine birdlime. (Jum-elastic is also used to give lli(! oil body and ehistlcity. NVlien I desirt! to make a balloon extraordinarily close, I give it a (irst coating of c( nipound varnish made ii]i of ('(pial parts whitis glue and glyc(;rine."
JiKONZK, (Joi.i), for furniture. — (fold bronze for furniture is a mixture of copal varnish mixi,'d with gold-colon^d bronze-powder. The last is bisulphatc of tin.
BiUHiiKs, Care of varni.shing. — A good way to keep brushes
PRACTICAL TECHNOLOGY. 167
is to suspend them by the handles in a covered can, keeping the points at least half an inch from the bottom, and apart from each other. The can should be filled with slowly-drying varnish up to a line about i\ inch above the bristles or liair. The can should I hen be kept in a close cupboard, or in a box fitted for the pur- pose. As wiping a brush on a sharp edge will gradually split the bristles and cause them to curl backward, and eventually ruin the brush, the top of the can should have a wire soldered along the edge of the tin, turned over, in order to prevent injury. Finishing brushes should not be cleansed in turpentine, except in V'xtreme cases. When taken from the can, prepare them for use by working them out in varnish ; and before replacing them, eleanse the handles and binding in turpentine.
Colors, Naturally transparent. — These are terra de sienna, asphaltum, dragon's blood, carmine, rose-pink, chemical brown, all the lakes, gamboge, and all the gums. Semi-transparent : um- ber, Vandyke brown, chrome red, emerald green, Brunswick green, ultramarine, indigo, and verdigris. Transparent colors j.re purer if ground in water ; allow them to settle, pour off the top part of the settlings : mix that with more water ; let it settle, and take the top half of that, which will be free from all sand and grit. Turpentine makes transparent colors work crumbly. Bleached boiled oil or white varnish is the best vehicle for flow- ing evenly.
Gilding without a Battery. — Dissolve 20 grains chloride of gold in a solution of cyanide of potassium, 1 oz. to 1 pint pure water. Put the solution of cyanide of gold in a glass or porce lain jar ; place in it the articles to be gilded in contact with a piece of bright zinc, in the solution near them ; the process will he hastened by a gentle warmth. If the gold is deposited on the zinc, rub a little shellac-varnish on it. The chloride of gold may Ije prepared by dissolving gold in aqua regia in the propor- tions of 16 grains gold to 1 oz. acid, and evaporating to dryness.
Gilding on Glass. — Mix powdered gold with thick gum- arabic and powdered borax ; with this trace the design on the glass, and then bake it in a hot oven. The gum is thus burned and the borax vitrified, and at the same time the gold is fixed on the glass. To make powdered gold, rub down gold-leaf with pure honey on a marble slab. Wash the mixture, and the pre- cipitate is the gold used.
Japan, Black and flexible. — Take burnt umber 4 ozs. , asphal- tum 2 ozs., boiled oil 2 qts. ; dissolve the asphaltum first in a little oil, using moderate heat; then add the umber (ground in oil), and lastly the rest of the oil, and incorporate thoroughly. Thin with turpentine.
Loom-Harness, Varnish for. — Mix linseed-oil 2 gals., gum- shellac 2i lbs., litharge 2 lbs., red-lead 1 lb., umber 1-| lbs., sugar of lead 1^ lbs.
Machinery, Painting. — The following colors contrast hand- somely : 1. Black and warm brown. 2. Violet and pale green. 3. Violet and light rose-color. 4. Deep blue and golden brown. 5. Chocolate and bright blue. 6. Deep red and gray. 7. Maroon
168 PBA.CTICAL TECHNOLOGY.
and warm green. 8. Deep blue and pink. 9. Chocolate and pea- green. 10. Maroon and deep blue. 11. Claret and buflf. 13. Black and warm green.
M.AJiBLE, To stain. — Blue, solution of litmus ; green, wax col- ored with verdigris ; yellow, tincture of gamboge or turmeric ; red, tincture of alkanet or dragon's blood ; crimson, alkantjt in turpentine ; flesh, wax tinged with turpentine ; brown, tincture of logwood ; gold, equal parts of verdigris, sal-ammoniac, and sulphate of zinc in fine powder.
Paint without oil. — Break an egg into a dish and beat slight- ly. Use the white only, if for white paint ; then stir in coloring matter to suit. Red-lead makes a good red paint. To thin it, use a little skimmed milk. Eggs that are a little too old to eat will do for this very well.
Paint, Reddish-brown, for wood. — The wood is first washed with a solution of 1 lb. cupric sulphate in 1 gallon water, and then with 4 lb. potassium ferrocyanide dissolved in 1 gallon wa- ter. The resulting brown cupric ferrocyanide withstands the weather, and is not attacked by insects. It may be covered, if desired, with a coat of linseed-oil varnish.
Paint to stand the action of hot water. — Clean the metal with turpentine or benzine. Then mix white-lead, carriage-var- nish, and spirits of turpentine, and give the metal two thin coats, and then a thick coat of white-lead and carriage-varnish, applied as quickly as possible.
PcTTY, Inde.structible. — Boil 4 lbs. brown umber in 7 lbs. linseed-oil for 2 hours ; stir in 2 ozs. wax ; take from the fire, and mix in Hi lbs. chalk and 11 lbs. white-lead, and incor- porate thoroughly.
Iron Sukfaces, Painting. — In mixing paints for iron surfaces, it is of the first importance that the best materials only be used. Linseed-oil is the best medium, when free from admixture with turpentine. A volatile oil, like turpentine, can not be used with advantage on a non-absorbent surface like that of iron, for the rea.sf)n tliat it leaves the j»aint a dry scale on the outside, which, having no cohesion, can be readily crumbled or washed away. Linseed-oil, on the other liand, is peculiarly well adapted for this purpose. It df)es not evaporate in any perceptible dejfree, but the large percentage of linolein which it contains combines with the oxygen of the air, and forms a solid, translucent substance, of resi- nous appearance, which possc.-^sj's much toughness and elasticity, and will not crack or blister by reason of the expansion and contraction of the iron witli variations of temperature. It is, moreover, remarkably adhesive, is impervious to water, and is very difficult of solution in essential fiils, spirits, or naphtha, and even in bisulphide of carl>on. Another important advantage of linolein la that it expands in dryinfr. which ]M'(Miliarly adapts it to iron surfaces ; since cracks, however minute, resulting from shrinkage, exjKise enough of the met«l to afford a chance ifor cor- rosion, which will spread in all directions, undermining the paint and causing it to scale off, beside discolorinjr it. In selectiufi' a paint for iron, meclianical adhesion is a consideration of the first
PRACTICAL TECHNOLOGY. 169
importance. Pitchy or bitumiuous films are especially effective as regards their adhesion to iron ; for example, solutions ot as- phalt or pitch in petroleum or turpentine. These are also very ef- fective as regards continuity, owing to the fact that, in drying, they form plastic films, which yield with the expansion and con- traction of the iron, and manifest no tendency to crack. If the surface is rusty, they penetrate the oxide scale, and envelop the particles very effectually, making them a portion of the paint. The solubility of such a film in water may be counteracted by mixinor it with linseed-oil. The experiment may easily be tried by mixing about 3 parts of Brunswick black with one of white, red, or stone colored paint, the body of which is composed of red or white lead or litharge. Red-lead is the best, for many reasons, if finely ground and thoroughly mixed with linseed-oil. Any one of several kinds of bitumen may be used, either natural mineral asphalt, pine pitch, or artificial asphalt, such as gas-tar or the re- siduum of petroleum distillation, in cases where the crude oil has been distilled before being treated with acid. This gives a very hard, bright pitcli, which is soluble in "once run" parafiine spirit, and which makes the base of an excellent, cheap, and durable paint for iron-work in exposed positions. Paraffine can be recom- mended for all classes of iron-work which can be treated hot. The most effective method of applying it is to heat the iron in vacuo, in order to expand it and open its pores, when paraffine, raised to the proper temperature, is run upon it. By this means the iron is penetrated to a sufficient depth to afford a very effectual pro- tection against oxidation, especially when a suitable paint is sub- sequently applied.
Lacquer, Deep golden. — Seed-lac 3 oz., turmeric 1 oz., dragon's blood i oz. , alcohol 1 pt. Digest for a week, frequently shaking. Decant and filter. Golden : Ground turmeric 1 lb., gamboge 1| ozs., ^um-sandarac 3ilbs., shellac f lb. (all in powder), recti- fied spirits of wine, 2 gals. Dissolve, strain, and add 1 pt. of tur- pentine varnish. Red: Spanish anatto 3 lbs., dragon's blood 1 lb., gum-sandarac Si lbs., rectified spirits 2 gals., turpen- tine varnish 1 c^t. Dissolve, strain, and mix, as last. Pale brass : Gamboge, cut small, 1 oz.. Cape aloes, ditto, 3 ozs., pale shellac 1 lb., rectified spirits 2 gals. Dissolve and mis as with the golden. Lacquers, Cliancjing : I^acquers of this description are called changing, because when applied to metals such as copper, brass, or hammered tin, they give them a lustre approaching that of the precious metals. Mix 4 ozs. of the best gamboge in 32 ozs. of spirits of turpentine ; in another vessel, mix 4 ozs. of dragon's blood witli same quantity of turpentine, and in a third vessel, 1 oz. of annotto with like amount of spirits. Keep the vessels exposed to the sun, in a warm place, for a fortnight, when the contents will be fit for use. By mixing these, any desired tint can be obtained. Another deep golden : Strongest alcohol 4 ozs., Spanish anatto 8 grains., powdered turmeric 2 drachms, red-saunders 12 grains. Infuse this mixture in the cold for forty-eight hours, pour off the clear, and strain the rest; then add powdered shellac A oz., sandarac 1 drachm, mastic 1 drachm, Canada balsam 1 drachm. Dis- solve in the cold by frequent agitation, laying the bottle on its side to present a greater surface to the alcohol. When dissolved.
1 70 PRACTICAL TECHNOLOGY.
add 30 drops of spirits of turpentine. Pale tin : Strongest
alcohol 4 ozs. , powdered turmeric 2 drachms, hay saJEfrou 1
scruple, dragon's blood, in powder, 2 scruples, red saunders i
scruple. Infuse, and add shellac, etc. , as to the last-described deep
golden. When dissolved, add 40 drops of spirits of turpentine. Lacquer should always stand till it is quite fine before it is used.
Letteking, Sign-painter's scale for. — The following is a con- venient table for sign-painters or others who have occasion to make lettering. Supposing the height of the capital letters to be ten, the widths are as follows : B, F, P, ten ; A, C, D, E, G, H, K, N, 0, Q, R, T, V, X, and Y, eleven ; I, five ; J, eight ; S and L, nine ; M and W, seventeen ; Z and &, twelve. Numerals : 1 equals five ; 2, 3, 5, 7, 8, nine ; 4, eleven ; 6, 9, 0, ten. Lower- case letters (height six and a half) : Width : a, b, d, k, p, q, x and z, seven and a half ; c, e, o, s, seven ; f, i, j, 1, t, three ; g, h, n, u, eight ; m, thirteen ; r, v, y, six ; w, ten.
Putty, Old, in sashes, To soften. — Run a red-hot iron over it : it will peel off easily.
Varnish, Black. — Alcohol 1 qt., aniline blue 184.8 grs., fuchsin 46.2 grs., naphthaline yellow 123.2. Dissolve by agita- tion in less than 12 hours. One application is sufficient. The mixture should be filtered when it will not deposit.
Varnish, Cheap gold. — The following is a cheap substitute for the ex])en8ive gold varnish used on ornamental tin-ware. Tur- pentine + gallon, asphaltum I gill, yellow aniline 2 ozs. , um- ber 4 ozs., turpentine varnish 1 gal., and gamboge -k lb. Mix and boil for ten hours.
Varnish, Copal, To make. — Dissolve 1 pt. camphor, by weight, in 12 pts. ether, then add best copal resin (pulverized) 4 pts., and place in a well-stoppered bottle. When the copal has partly dis- solved and has become swollen, add strong alcohol 4 pts., oil of turpentine i pt. Shake, and allow to stand for a tew hours. This makes an excellent varnish.
Varnish for Maps. — Take equal parts genuine Canada balsam and oil of turpentine ; mix. Set the bottle in warm water, and agitate until the solution is perfect ; then set in u warm place a week to settle, when pour off the clear varnish for use. Before using, cover the map with a thin solution of pure glue.
V.XRNisn, Parisian. — Dissolve 1 part of .shellac in 3 to 4 parts o| alcohol of 92 per cent in a water-bath, and add cautiously-distill- ed water, until a curdy mass separates out, which is collected and i)reHse(l between linen. 'Vho liquid is lilt<;red through paper, all the alcohol reinove<l liy distillatinn fmiii the water-bath, and the resin removed and dried at 100*^ Centigrade, until it ceases to lose weight. Dissolve it in double its weight of alcohol of 96 per cent, and i)erfume with laveiuler oil.
VV.\lni:t Stain for Wood.— Water I (|t., washing soda 1^ ozs., Vandyke br.wn 2* ozs., bichromate of potash i oz. Boil lor ten minutes, and apjtly with a brush, either hot or cold.
PRACTICAL TECHNOLOGY.
171
Whitewash, To improve. — Add a strong solution of sulphate of magnesia.
Wood, Red stain for. — A permanent and handsome reddish color may be given to cherry or pear tree wood by a coat of a strong solution of permanganate of potash, left on a longer or shorter time according to the shade required.
HINTS ABOUT DRAWING AND SKETCHING.
Camera Ltjcida, The.— This is probably the most reliable op- tical device employed for copying. The principle of its construc- tion will be understood in tlie diagram marked 2 in the engrav- ing. The glass is simply a four-sided prism, having one right angle, one of 135°, and two of 67^°. When disposed as repre- sented, the rays from the object pass into it without any appreci- able refraction, and are totally reflected from the lower inclined
FIG. 1 —THE CAMERA LUCIDA.
side, and again from the upper inclined side, emerging near tha summit in a direction almost perpendicular to the top face, so that the eye sees on the paper placed beneath an image of the object. If the image be traced by the pencil, a very correct out- line, not reversed, is obtained. The use of the device requires practice. The nearer the object copied is brought to the prism, the larger is its image, and vice versa.
172
PRACTICAL TECHNOLOGY.
A simple method of constructing the camera Uicida is shown in Fig. 2, and is the invention of Mr. H. E. Mead, artist of the Scientific Ame- rican. The prism can be obtained at a small cost from any optician, and the rest of the apparatus any one can cut out of black walnut with a knife, and per- haps a gimlet. The thumbscrews used are of brass, of the kind employed for shutter-fastenings, and can be procured of any hardware dealer for a few cents eacli. B is the prism, and A is a sec- tion of one of the joints, showing how the apparatus may be easily adjusted. A movable rod, secured by a thumb- screw, regulates the height ot the prism, and the single clamp shown secures it to the tabk". The cost of the whole is about seven dollars.
Drawing-Board, Reflecting. — A flat board is provided, with two uprights, both of which, with the board, are grooved to hold a pane of glass in a per- l)cndicular jjosition. The drawing to be copied is secured to the board on the left of the glass, and the blank paper is fas- tened on the right. The artist now PIG. 2.— A SIMPLE CAMERA stands to the left, as represented in the LuciDA. illustration, and looks down upon the
glass at a very oblique angl(\ The original drawing is re- flected from the ])olish('d surface of the pane to his eye, and at the same time he sees tlie white ])aper through the transparent glass, Bo that the lines of the model appear transferred, but reversed, upon the paper. These are followed with a pencil, and the outline is made.
Drawino, Colors used in mechanical. — The annexed table shows different materials, and the colors used to denote them :
Cast-iron, ... Paine's gray and a little Indian ink.
" (another tint) Ordinary neutral tint. " " Prussian blue and Indian ink.
Prussian blue (or cobalt). A ]>ur])le made by mixing crimson lake
and Prussian blui-. <ianibi)ge or yellow ciidrniuni. Iniiian red mixed willi a little lake, liurnt umber. Indian hmI. Indian yellow or cadmium, toned with
white! Chinese white ami Indian ink, toned
with yellow. Broken, irregular straight lines, with
li(juid copix-raH,
Wrought-iron, Steel,
<iun-metal. ('opper, \Vo<.d, Brick (red), " (yellow),
Stone color,
Water,
PRACTICAL TECHNOLOGY.
178
Paper, Transfer. — A good transfer paper for copying monu- mental inscriptions and metallic patterns may be made by rubbing
A REFLECTING DRAWING-BOARD.
a mixture of black-lead and soap over tlie surface of common silver paper .
Paper, Tracing, Temporarily trnnsparent. — This is made by dissolving castor-oil in absolute alcohol, and applying the liquid to the pajjer with a sponge. The alcohol speedily evaporates, leaving the paper dry. After the tracing is made, the paper is immersed in absolute alcohol, which removes the oil, restoring the sheet to its original opacity.
Paper, Tracing, that can be washed. — This is prepared by first saturating writing-paper with benzine, and then immedi- ately coating it lightly with a varnish composed of boiled bleached linseed-oil 20 parts, lead shavings 1 part, oxide of zinc 5 parts, Venice turpentine i part. Mix, boil for 8 hours, and, after cooling, add white gum-copal 5 parts, and gum-sandarac i part.
Pantagraph, The. — This consists of four rulers, jointed toge- ther at their intersections, and having, at two of the angles, sup- ports terminating in round points or smoothly-running casters. At one of the other angles is a weight to which the apparatus is pivoted, and which holds it in place, and at the fourth corner is a tracing-point, shown in the hand of the operator. Directly across the frame thus made, and pivoted at its ends to the centres of two of the bars, is a fifth bar, through the middle of which passes a pencil. Along half the length of the two side-bars, and
174
PKACTICAl, TECHNOLOGY.
also of the central bar, are made perforations, so that the length of the rulers can be shortened as rendered necessary. The tracmg point is moved over the outline to be followed, and its motion is communicated to the series of rulers, which, by a kind of paral- lel movement actuate the pencil to describe precisely the same
THE PANTAGRAPH.
line, equal in dimension to thiit of the co])y, or enlarged or re- duced. Tlie scales of the two drawings are to each other as the distances of the pencil and of the tracing-point from the pivot, and these distances are adjusted by altering the position of the joints in the holes.
Pencils, Copvinc, To make. — Pencils are sold by stationers, the marks of which maybe copied in the same manner as writing made by the pen with ordinary copying-ink. The method of lir('i)ariiig the leads is as follows : A thick paste is made of gra- ])hite. linely ]>uiveri/.ed kaolin, and a very conceut rated solution of aniline blue, soluble in water. The mixture is pressed into cylinders of suitable size and dried, when it is ready for use. (Slum arable may be substituted for the kaolin.
St:N DuAWiNf;. — Draw with a ])eMcil on a piece of tracing- paper the desired design ; go over the lines with very blaek ink, turn tlie paper over, and ffjjlow the lines also witli ink on the reverse side ; fasten tli«' paper by the corners to a pane of clear glass. Make a solution f)f .J oz. bichroniati^ of potash in 2 ozs. hot water, strain \\hen eold, aiul with this bi'usli over the ])a])er or silk on whiih the design is to l)e printed. Plac<! the material t liuH pre]>ared under the ])!i])er on the glass, and <himp all together. f'^.xpose the wlioh- to bright sunliglit, glass uppermost, then design, tlien biehromate paper ; in a few inr)ments, the design will be print-
PKACTICAL TECHNOLOGY.
175
ed deeply. Wash and soak for a short time in clean water (to fix), dry, and press with a warm fiat-iron.
Ruler, Perspective. — This is a simple arrangement for draw- ing lines in correct perspective. It consists in three arms of equal length pivoted together at one end by a screw-clamp. Two pins are inserted in the drawing-board, against which two arms of the ruler abut. The angle of these arms and the position of the pins are governed by the distance required for the vanishing-
THE PERSPECTIVE-EULER.
point, as the greater the angle, the further the same is removed, and vice versa. Once adjusted, the parts are clamped firmly to- gether, and the lines ruled by the upper side of the arm which rests upon the paper. The arms at an angle are kept in contact with the pins, and the ruling arm is moved up or down the paper.
Sketching-Frames. — A square frame is hinged to the top of an ordinary drawing lap-board, so that it will stand in an upright position (as in Fig. 1). Across this is stretched a number of threads or wires at equal distances apart so as to divide the inte- rior space into small squares. The paper on the board is simi- larly divided by light pencil-lines ruled over the surface. In making the sketch, the artist draws so much of the view as he sees through one of his squares in the frame, into the correspond- ing ruled square on the paper, and thus having a large number of straight lines to refer to is very readily enabled to locate the details of the picture. It is, however, necessary to use but one eye when looking at the landscape, and to keep this eye always at the same place, for which purpose an additional eye-piece may be added, simply consisting of a ring supported on a stand.
Sketching, Out Door, Simple apparatus for. — Provide a
176
PEACTICAL TECHNOLOGY.
small table with, drawer ; mount two grooved movable uprights at one end, with glass between the grooves ; place an upright with a small eye-hole at the opposite end of the table, as shown in the engraving. Wash the glass with a thin solution of gum
THE SKETCHING-FRAMB.
arable and rock candy (20 parts ffum to 1 o£ candy). When the glass is dry, it is ready for use. Look through the small hole to get the object subtended by the glass, and with a soft crayon outline the subject on the prepared surface ; remove the glass and lay it
ii; -K 1. 1 c III M
M'l'AltATt'H.
over your Hkclcli. If you rciiuiri' lliu outline, you .sliouM liave a second plate of glass, and trace over it the reverse way with cliarcoul. then lay your paper on, and a little gentle rubbing will transfer the outline.
PRACTICAL TECHNOLOGY.
177
Tracing-Table, Transparent. — This, as shown in the illus- tration, consists of a square-bottomed bos, the tops of the sides of which are inclined like those of a writing-desk. The back is open, and, as the apparatus rests on the table, abuts against a window. The window-shade is drawn down to meet the upper part of the device, so that the liglit enters through the back of the latter.
A TKANSPAKENT TRACTNG-TABLE.
and the interior, being lined with white iiaper, is reflected up through the inclined glass top ; the original drawing is laid upon the glass, and a sheet of tissue-paper ruled off in squares is placed above it. Being brilliantly illuminated from below, the drawing would readily sliow through, and might be copied, square by square, as belore described.
178 PRACTICAL TECHXOLOGY.
SIMPLE GALVANIC BATTERIES AND ELECTRO- PLATING RECIPES.
Battery Carbons. — Tliese can be readily cut witli a hand- saw moistened in water.
Battery, Daniell's, Substitute for copper in. — Brighten sheets of ordinary sheet-tin and plunge into a very weak copper-plating solution, in connection witli a galvanic battery of very low quan- tity. In 15 or 18 hours a tenacious film of copper will have been deposited upon the tin, and the plate can then be bent in shape suitable for the battery.
Battery, Galvanic, A cheap. — Mr. W. M. Symons proposes a cheap but convenient galvanic battery : each of the zinc plates js 2 in. square, and covered with fustian or other fabric, out- side which thick copper wire is wound to form the other plate ; the exciting liquid is weak chloride of zinc. Pairs of plates thus made can be arranged in series to form a battery to give out weak currents for a great length of time.
Battery, Galvanic, A simple. — Take a glass tumbler, and place in the bottom a sheet of copper, having an insulated wire attached and extending out of the tumbler. Cover the cop])er with blue vitriol, and suspend a sheet of zinc near the top. Fill the tumbler with water. Connect the zinc and copper together for 48 hours, and the battery will be ready for use.
B.\ttery, Galv.\nic, Exciting liquid for. — Dissolve protosul- phale of iron, 20 i)ts., by weight, in 'Sit pts. of water, stir in a dilution of sulphuric acid (eijual parts of acid and water,) 7 pts., and add 1 part nitric acid similarly diluted. This liquid has great energy, and disengages no deleterious fumes.
B.\ttery Zincs, Amalgamation of. — The simjdest and quickest method consists in immersing the zinc in a li(}uid comj)Osed of nitrate of mercniry and hydrochloric acid. A few moments are sufficient for the complete amalgamation of the zinc, however soiled its surface may be. With a quart of this liquid, which costs less than 50 cents, 150 zincs can be aiualgamated. The liquid should be ])repared in this manner : Dissolve in warm water 200 grains of mercury in 1000 grains of aqua regia (nitric acid 1 part, liydrochloric acid ;j ])arts). When the mercury is dissolved, add 1000 grains of hydrochloric acid.
Electro-Maonets, Softening. — Magnets or armatures for electro-motors may be softened as follows : Heat the iron to an even dull-red lieat all over ; and if the surface of the iron has not V)een faced off in a machine, liglitly file it to remove the scale, and then immerse it in common srjftsoap, allowing it to n-main therein until it is <|uitr cold. Then reheat the magnet to an <'ven red heat whose redness is ])arely ])erceptible, and bury it in pul- verized lime, wherein it must also remain until <|uite cold, wljen the metal will be found as soft as it is possible to make it, and the blade of an ordinary penknife will cut it. At the second heating, (lie iron will emit a light blue flame, showing the effect
PRACTICAL TECHNOLOGY. l79
of the immersion in the softsoap. The capability of receiving strong magnetic power may be, by this process, very much in- creased.
Electro-Plated Paper or Cloth. — Make a solution of ni- trate of silver, and add ammonia until the precipitate formed at first is entirely dissolved. Place the paper or cloth for 1 or 3 hours in the liquid. After removing and drying, expose to a current of hydrogen gas, by which the silver is reduced to a metallic state, and the paper or fabric becomes so good a conduc- tor of electricity, that it maybe electro-plated with copper, silver, or gold in the usual manner.
Electro-Plating, Cleansing metals for. — Most articles are rapidly cleaned by chemical means. The first of these is the re- moval of grease by boiling in a solution of caustic soda, made by boiling 2 lbs. of common washing-soda and ^ lb. cjuicklime in a gallon of water ; after this they should be well brushed under water. The further processes will depend upon the nature of the objects.
1. Silver is washed iu dilute nitric acid, then dipped for a mo- ment in strong nitric acid, and well washed. Care must betaken that the water does not contain chlorine salts ; if the ordinary supply does so, the first rinsing after acids must be made in wa- ter J5repared for the purpose by removing the chlorine by adding to it a few drops of nitrate of silver, and allowing the chloride to settle.
2. Copper, brass, and German silver are washed in a pickle of water 100 parts, oil of vitriol 100 parts, nitric acid (sp. gr. 1.3) 50 parts, hydrochloric acid 2 parts. Spots of verdigris should be first removed by rubbing with a piece of wood dipped in hydro- chloric acid ; they are then rinsed in water.
3. Britannia metal, pewter, tin, and lead can not be well clean- ed in acids, but are to be well rubbed in a fresh solution of caus- tic soda, and passed at once, without washing, into the depositing solution, which must be alkaline.
4. Iron and steel are soaked in water containing 1 lb. oil of vitriol to the gallon, with a little nitric and hydrochloric acids added. Cast-iron requires a stronger solution, and careful rub- bing with sand, etc., to remove scale and the carbon left by the acids. It is an advantage at times to connect them to a piece of zinc while cleaning. These metals should be cleaned just before placing in the depositing cell ; and if they are placed in an alka- line solution, they should be rinsed and dipped in a solution of caustic soda, to remove all trace of acids.
5. Zinc may be cleaned like iron, with a dip into stronger acids before the final washing.
6. Solder requires special care, as the acids used with the ob- jects produce upon it an insoluble coating, and an obstinate resist- ance to deposit is set up at the edge of the solder. The same remark applies to soft -metal edgings and mounts. These should be rubbed with a strong caustic-soda solution, rinsed, and then treated as follows : Make a weak solution of nitrate of copper by dissoh-ing copper in dilute nitric acid ; to a camel-hair or other soft brush, tie 3 or 4 fine iron wires to form part of the
180 PRACTICAL TECHNOLOGY.
brush ; dip this in the nitrate of copper, and draw over the solder, taking care that some of the iron wires touch it ; a thin adherent of copper will form, and upon this a good deposit will take place. 7. Old work for replating must have the silver and gold care- fully removed ; if this is not done, there is apt to be a failure of contact at the edges of the old coatings, which causes blisters and stripping under the burnisher. The best mode of stripping is wiih the scratch-brush, etc., but chemical means may be used. Gold is dissolved by strong nitric acid, to which common salt is gradually added ; it may be collected afterward by drying and fusing with soda or potash. Silver is similarly dissolved by strong sulphuric acid and crystals of saltpetre, and recovered by diluting and precipitating with hydrochloric acid, then reducing the chloride either by fusion with carbonate of soda, or by acid and zinc cuttings. Copper can be removed from silver by boiling with dilute hydrochloric acid, and tin and lead by a hot solution of perchloride of iron.
Insulators, Rubber, Substitutes for.— Ivory and guaiacura wood, which are both relatively good conductors, become nearly non-conductive if stove-dried and saturated with certain oily and resinous liquids, which close up the pores of the bodies in (jues- lioii, and prevent moisture from penetrating within. Other kinds of wood can be modified in the same manner.
Sawdust of bard wood, agglutinated with blood and submitted to a considerable pressure, so as to mould it into a solid, tenacious body, is a good insulator for voltaic currents. After remaining six days in a damp cellar, it showed no galvanometric deviation.
Iron, Electro-plating with silver on. — The direct irciy : The ar- ticle should first be rendered free from rust by rubbing with em- ery-cloth, or by (lipping it into a pickle composed of sulphuric acid 2 ozs., hydnjciiloric acid 1 oz., water 1 gal. After the article has remained some time in this pickle, it should be taken out and the rust removed by a brush and wet sand. If the oxide can not be easily clfaiicd off, it must be returned to the pickle. As soon as the article is rendered bright, it is W'ashed in a warm solution of soda, for the purpose of removing all grease. Lastly, it is well rinsed in hot water, and immediately placed in the plating solu- tion, which should contain only about onc^ fourth as much silver as that usinl for plating copper and brass articles. The battery power must al.so be weak. When the object receives a sliirht coating, the process may Ix; carried on mort! rapidly by increasing the battery j)Ower, and by placing the article in a much stronger l)lating bath, using about 1 oz. silver in a gallon of solution. The indirect method consists in first coating the iron with copper, which insures success. C'o])per adheres firmly to iron, but silver does nr)t ; hence rop])er acts the part of a go-lx'tween. After the articli! has i)(-en cleaned, as above described, it is coated with cojipcjr by placing it in a solution comiiostMl of (-arbonate of potas- 8a 4 OZ8., sulphate of copjjer 2 ozs., li(|uid ammonia about 2 oz., cyanide; of i)otassinni (i ozs., water about 1 gal. 'i'lie sul])hate of co|)per nniy be dL^^solved in warm rnin-wafer, iinil, when cold, the carbonate of potassa and iiinnionia added : the ])recipilai(? wlH!n formed is redjssolved. '{'he cyanide of potassium should
PRACTICAL TECHNOLOGY. 181
now be added, until the bluish color disappears. Should any pre- cipitate be found in the bottom of the vessel, the clear solution may be poured off from it. The solution is worked culd, and with modi rate battery power. Let the article remain in the bath until a thin film of copper is deposited, then remove quickly, rinse in hot water, and place in the silvering solution, where the process may go on as rapidly as if plating a copper article.
Pewter, Electro-plating. — Take 1 ounce nitric acid, and drop pieces of copper in it until effervescence ceases ; then add ^ ounce water, and the solution is ready for use. Place a few drops of the solution on the desired surface, and touch it with a piece of steel, and there will be a beautiful film of copper deposited. The application may be repeated if necessary, though once is general- ly sufficient. The article must now be washed and immediately be placed in the plating bath, when deposition will take place with perfect ease.
Steel, Magnetization of.— If a properly-tempered steel needle be introduced into a magnetizing bobbin connected with a battery of constant current, battery and bobbin comprising the circuit, it ac- quires a total determined magnetism at the end of a period which appears not to exceed that of its introduction. On slowly with drawing the needle, it is found to retain residual magnetism,"whicli , together with the total magnetism, increases with each repeated introduction until a limit is reached. The needle may be mag- netized in the bobbin by three other methods : 1. EdaUishment : Introduce the needle ; establish the current ; slowly withdraw the needle. 2. Interruption : With a closed circuit introduce the needle slowly ; break the current and withdraw the needle. .S. Instantaneous charge : Introduce the needle ; establish and break the current ; withdraw the needle. Kepetitions of any of these three processes (all things being equal) insure an augmen- tation of the needle's magnetic moment. The last method is the best, but care must be taken to introduce the needle and current always in the same position, so as not to reverse the poles.
USEFUL CHEMICAL RECIPES FOR DETECTION OF ADULTERATIONS, FILTERING, INK-MAKING, ETC.
Beer, To prevent, from turning sour while on draft. — A slate cistern is made, having a wooden lid, fitting accurately, floating on the surface of the liquid. The sides of the lid are be- veled, so that a sharp edge is presented to the walls of the cistern, and iilong this edge a strip of india-rubber is fastened, which forms, with the bevel on the upper side, a V-shaped space, into which wet sand is packed in order to keep the rubber in close contact with the sides of the cistern, and so to exclude the air from the same. A hole is formed in the lid, having a stuffing-box, through which a pipe passes into the liquid, and the connection
182 PRACTICAL TECHNOLOGY.
to the beer-engine is made in the usual way. The end of the pipe in the liquid is closed, but perforations are made in the sides about an inch therefrom : this prevents any sediment escaping with the fluid. Atmosplieric pressure, acting on the lid, forces it to descend as the liquid is removed from under it, and thus a constant flow is obtained by means of the engine. By letting the cistern into the ground, the temperature of the liquid will remain nearly uniform the year round.
Beek, To clarify. — Take isinglass, finely shredded, 1 lb., sour beer, cider, or vinegar 3 or 4 pints ; macerate together till the isinglass swells, and add more of the sour liquid until a gallon has been used. Strain and further dilute. A pound of good isinglass should make 13 gallons finings, and 1-^ pints finings is enough to clear a barrel of beer.
BisuiiPHiDE OF Carbon,To deodorize. — Distill with quicklime, the two substances having been in contact for 24 hours. The distillate is received in a flask partially filled with clean copper turnings. The lime remaining in the retort is strongly colored.
Campiiok, To powder. — Take camphor 5 ozs., alcohol 5 fi. drachms, glycerine 1 fl. drachm. Mix the glycerine with the al- cohol, and triturate it with the camphor until reduced to a fine powder.
Candles, Paraffine. — To dye beautiful red, i)urple, or violet tints, use aniline colors.
Casks, Mouldy, To disinfect. — Wash first for about 5 minutes with an alkaline solution of soda, and then soak for 1 or 2 days with a liquor acidulated with hydrochloric acid.
CuLOROFORM, Purifying decom])osed. — Shake up the chloro- form with a few fragments of caustic soda.
Dyeing Leatiiku Yellow. — Picric acid dyes leather a good yellow, without any mordant ; it must be used in very dilute solution, and not warmer than 70° Fahr. Aniline blue modifies this color to a fine green.
Dyes, Testincj, for Adilteratiox. — Red dyes must neither color soap-and- water nor linu'-wat(;r, nor must they themselves become yellow or brown after boiling. This test shows the presence or absence of Brazil-wood, arcliil, safflower, sandal- wood, and the aniline colors. Yellow dyes must stand being boiled with alcohol, water, and lime -watir. The most stable yellow is maddei'-ycllow ; the least stable are aiuitto and tur- meric ; fustic is rather better. Blue dyes must not color alcohol reddish, nor must they decompose on boiling with hydrochloric acid. Tlie best ])urph; colors are com])oscd of indigo and codii- neal.or purpnrine. The forniiT test applies al.'^o to tlu-m. Orange dyes must color luMtlier water nor alcohol on boiling ; green, iieitlier alcohol nor hydrochloric acid. Brown dyes must not io.'^e iheir color on standing with alcohol, or on boiling with wat(!r. If black colors liave a basis of indigo, they turn greenish or blue on Itoiling with so<liniii eurhonate ; if the dye l)e ])ure gall-nuts, it turns brown. If tin; material changes to red on boiling with liydrochloric acid, the coloring matter is logwood without a basis
PRACTICAL TECHNOLOGY.
183
If it changes to blue, indigo is
A SIMPLE FILTER.
of indigo, and is not durable, l^resent.
Filtering, Hot. — The apparatus consists of a tube of soft sheet-lead, which can be wound around the funnel containing the filter in the form of a spiral. One end of the tube passes through a cork in the neck of a flask, in which water, or other liquid of higher boiling-point, is boiled ; the other end dips into a receiver, into which the condensed liquid flows.
Filter, A simple. — The engraving represents a very good filtering apparatus. The best material for the box would be soapstone ; the next best material, iron. Mott's cast- iron tank-plates come of a con- venient size — 18 X 18 inches and 9 X 18 inches. These may be galvanized or coated with slate-paint.
Freezing-Powders. — (1) Four pounds sulphate of soda, 2i pounds each of muriate of ammonia and nitrate of pot- ash ; when about to use, add double the weight of all the ingredients in water. (2) Equal parts of nitrate of potash and muriate of ammonia ; when required for use, add more than dou- ble the weight of water. (3) Nitrate of ammonia and water in equal proportions. (4) Carbonate of soda and nitrate of am- monia equal parts, and 1 equivalent of water.
Filters, To make charcoal. — One method consists in pulveriz- ing animal charcoal until reduced to an impalpable powder. This is mixed with a definite proportion of Norway tar and a com- pound of other combustible substances. The combined materials are then properly amalgamated with liquid j^itcli, and the whole kneaded up into a homogeneous plastic mass which admits of being moulded into slabs or blocks of any required dimensions and shape. These blocks, having been allowed to dry and harden, are subsequently carbonized by being subjected to a process of incineration by heat ; and in this manner all the combustible ingredients are burned out, leaving nothing behind but the animal charcoal in the form of a block of charcoal, permeated throughout by innumerable pores.
Gases, Drying. — Anhydrous phosphoric acid is the best sub- gtauce known for this purpose.
Glycerine, Adulteration of, with sugar and dextrine. To detect, — To 5 drops of glycerine add 100 to 120 drops of water, 0.4 to 0.6 grain of ammonium molybdate, 1 drop pure nitric acid, and boil for a minute and a half. If any sugar or dextrine is present, the mixture will assume a deep-blue color.
Glycerine, Purification of. — To purify glycerine which has been for some time in use, add 10 lbs. iron-filings to every 100 lbs. of the impure liquid. Occasionally shake it and stir the
184 PRACTICAL TECHNOLOGY.
iron. In the course of a few weeks, a black gelatinous mass will collect on the bottom of the vessel, and the supernatant liquid will become perfectly clear, and can be evaporated to remove any excess of water that may have been added to it.
Glycerine, Testing. — When treated slowly with sulphuric acid, it should not turn brown ; with nitric acid and nitrate of silver, it should not become cloudy ; and vvheu rubbed between the fingers it should not emit a fatty smell.
Hides, To preserve. — Carbolic acid is used in South-America and Australia for this purpose. The immersion of hides for 24 hours in a two per cent solution of carbolic acid, and subsetjuent- ly drying them, has been successfully substituted for the more tedious and expensive process of salting.
Hydrocarbons, Classification of. — The classification usually adopted by distillers is as follows : All above 88° of Baume's hydrometer is called cliymogene, from 88° to 70° gasoline, from 70° to 60^ naphtha, from 60" to 50° benzine, from 50° to 35° kero- sene, from 35° to 28° lubricating-oil.
Ink, Blue. — Prussian-blue 6 parts, oxalic acid 1. Mix with water to a smooth paste. Dilute with rain-water, and add a little gum-arabic to prevent spreading.
Ink, Copying, used without a press. — Coarsely-broken extract of logwood 1 oz., carbonate of soda (crystallized) 1 drachm : heat in a porcelain capsule with 8 ozs. distilled water until the solution is of a deep-red color. Remove from fire and stir in glycerine 1 oz., neutral chromate of potash dissolved in a little water 15 grains, and a mucilaginous solution of 2 drachms finely-pulverized gum-arabic. Kee})S well, never recjuires a press for copying, and does not attack steel pens. The impression is taken on thin moistened copying-paper, at the back of which is jilaced a sheet of writing-paper.
Ink from Elderberries. — Bruise the berries, place them in an earthen vessel, and keep in a warm place for 3 days. Press out and filter. Add to 12^ ozs. of this filtered juice 1 oz. sulphate of iron and the same quantity of pyroligneous acid. This ink is violet at first, and afterward becomes black.
Ink, Indkliiu.k, for marking linen.— (1) Bichloride of copper, 8^ grains, dissolved in distilled water, 30 grains ; then add common salt, 10 grains, and liquid ammonia, iiA grains. A solution of 30 grains hydrochlorate of aniline in 20 grains distilled water is thin added to 20 grains solution of gum-aral)ic, containing 2 pts. water, 1 pt gum arable, and 10 grains glyetM-ine. Four jjurts of the aniline solution tiius prei)ared are mixed with 1 part of the copper solution. This ink can be used with a steel pen. it is green at first, but becomes black in a ftnv days or by application of liot iron. It is absolutely indelil)le, and the finest devices can be written with it. It is bettiT to mix the two solutions only just before using. (2) For very fiiu; linen, take a solution of nitrate of silver, 4 jtts., in distilled water, 2-t ])ts. Adil li(|uid aininonia until the precipitate formed is dissolved. Then a little sap-green and indigo are ground together and mixed with a so- lution of gum-arabic, 4 pts., and this is mixed with tlie nitrato
PKACTICAI, TECHNOLOGY. 185
of silver solution. The whole is then diluted until it occupies 32 parts. It turns black as No. 1 does.
Ink, To restore dim. — Cover the letters with solution of ferro- cyanide of potassium, with the addition of diluted mineral acid (muriatic) ; upon the application of which the letters will change to a deep-blue color. To prevent the color from spreading, the ferrocyanide should be put on first, and the dilute acid added ujDon it.
Inks, Aniline. — Violet ink is obtained by dissolving one part of aniline violet-blue in 300 parts of water. This ink is quite limpid, dries quickly, and gives a remarkably dark color. It is necessary that new pens should be employed in using it, as the smallest quantity of ordinary ink mixed with it causes its altera- tion. Blue ink is made by dissolving 1 ])art of soluble Paris-blue in 250 parts of boiling water ; red ink, by dissolving 1 part of soluble fuchsiu in 200 parts boiling water. While ordinary inks are decomposed by numerous substances, and notably by hydrochloric acid, aniline inks are completely ineffaceable from the paper on which they are used. They resist the action of acids, and even of chlorine.
Inks, Sympathetic. — Yellows (1): Sulphate of copper and sal- ammoniac, equal parts, dissolved in water ; (2) onion-juice ; both visible on heating Black (1) : Weak infusion of galls. This is turned black by weak solution of protosulphate of iron. (2) Weak solution of protosulphate of iron. Turns blue when moistened by weak solution of prussiate of potash, and black by infusion of galls. Brown : Very weak solutions of nitric, sulphu- ric, muriatic acids, common salt, or nitrate of potash. Visible on heating. Green : Solution of nitromuriate of cobalt. Brought out by heat ; fades when cool. Rose-red : Acetate of cobalt solu- tion, with a small quantity of nitrate of potash. Acts as pre- ceding. Solutions of nitrate of silver and terchloride of gold become permanently dark when exposed to sunlight.
Ink, White, for colored paper. — 1 part muriatic acid, and 20 parts starch-water. Very dilute oxalic acid may also be used. Write with a steel pen.
Ivory and Bones, Bleaching. — Spirit of turpentine is very efficacious in removing the disagreeable odor and fatty emana- tions of bones or ivory, while it leaves them beautifully bleach- ed. The articles should be exposed in the fluid for 3 or 4 days in the sun, or a little longer if in the shade. They should rest upon strips of zinc, so as to be a fraction of an inch above the bottom of the glass vessel employed. The turpentine acts as an oxidizing agent, and the product of the combustion is an acid liquor which sinks to the bottom, and strongly attacks the bones if they be allowed to touch it. The action of the turpen- tine is not confined to bones and ivory, but extends to wood of various varieties, especially beech, maple, elm, and cork.
Ivory, Imitation.— To liquid chloride of zinc of 50° to 60° Baume, add 3 per cent of sal-ammoniac ; then add zinc- white until the mass is of proper consistence. This cement may be run into moulds, and when hard becomes as firm as marble.
18G PRACTICAL TECHNOLOGY.
Light, brilliant white, To make a. — Fill a small vessel of earthenware or metal with perfectly dry salpetre or niti'e, press down a cavity into its surface, and in this cavity place a piece of phosphorus ; ignite this, and the heat given off melts a sufficient quantity of the nitre to evolve oxygen enough to combine with the phosph(M'us, and the effect is to produce the most magnificent white light which chemistry can afford.
Mica. — The best comes from th(3 Eastern States. New-York mica is good. Canada mica is of several different shades, from light brown to intensely black.
Oil, Cotton-Seed, Refining. — One hundred gallons of the crude oil are placed in a tank, and 8 gallons of caustic potash-lye, of 45° Baume, are gradually added and well stirred for several hours ; or the same quantity of oil is treated with about 6 gallons of soda-lye of 25° or 30° Baume, and heated for an liour or more to about 200° or 240° Fahr., under ])erpetual stirring, and left to settle. The clear yellow oil is then .«e]iarated from the brown soap stock, and this dark soap sediment is placed into bags, where the remainder of tlie oil will drain off ; and the sediment has a marketable value of 3 or 4 cents a i)c)und for soap-makers. The potash-lye has to be made in iron pots, but tlu; oil and lye may be mixed in wooden tanks.
Oils from Plants, odoriferous. Extraction of. — This can be done by glycerine. The fiowers are intnxhiced into tlu^ liquid and left for 3 weeks. The glycerine is then drained off, and may be dissidved in all i)ri)porti()ns in alcohol or water to make perfumed liquids or washes.
0[i,s, Liii{i{i('ATiNfi,T(^stingfor acids in. — Dissolve a crystallized pie(;e of carbo.iatc! of soda al)out as large as a walnut in an (Mjual i)ulk of water, and |)lace, the solution in a Hask with sonu; of tlie oil. if, on settling after thorough agitation, a largi; quantity of precipitate forms, tlu; oil should be rejected as impure. As oils are often clarified and l)leached with acids, which injure the metals on which they are usimI, this is an inii)ortant point to know.
On,, Si'iCHM, To prevent gumuiiug. — It may he purified by agi- tating 100 parts oil with 4 parts chloride of lime and 12 water; a small (piantity of decoction of oak hark is alterward added to remov(! all tnici-sof gelatinous matter which it retains, and tlu^ mixture is left to settle. Tlu^ clear oil is afterward agitated with a snuill i)orlion of sul|)huric acid, again clarified by subsi- dence), and waslied to remove adhering sulphuric acid. The ad- dition of mineral oils, as heavy kerosi-ne, has also tlie tendency to prevent guMiniing, or at: least greatly to diniinisli it.
Oll,H,V()i,ATii-K, Explosion of. — A mixture of 2 ]iartH of perfectly dry permangatiati! of potassium with 2 or 3 parts of concentrated sulphuric; acid is a most powerful oxidizing agent, owing to the sepiiratioii of permanganic acid and its immediatf! decomposition with the liheratioi) of oxygen. Volatile oils are violenily affect- ed l)y this mixture, if about 10 drops are pluced in a little disli and then touched with a stout glass, rod previously dipped into the mixture. 'I'he following produce exploBJons, often most vio-
PKACTICAL TECHJ^"OLOGY. 187
lently : oils of thyme, mace, turpentine (rectified), spike, cinna- mon, origanum, rue, cubebs, and lemon. The following oils are simply inflamed, particularly if poured upon blotting-paper and touched with the mixture, though under certain still unknown circumstances explosion may occur : oils of rosemary, lavender, cloves, rose, geranium, gaultheria, caraway, cajeput, bitter- almond, and rectified petroleum. The following substances are ignited without explosion : alcohol, ether, wood-spirit, benzole, chlorelayl, sulphide of carbon, and cotton. Gun-cotton and gun- powder are not ignited.
Petroleum, Test for illuminating. — Fill a tumbler full of water at 110° Fahr. Stir in a tablespoonful of the oil to be tested, and leave until the oil reaches about the same temperature. Pas^s a lighted match over the oil as it fioats on the surface. If the oil does not ignite, it can be safely used ; if it does, discard it, how- ever cheap the price may be. Improved test proposed by Dr. Van der Weyde : Fill a narrow test-tube with the petroleum to be tested, close it with the finger, invert it, and plunge entirely in water of some 140° Fahr. ; wait until the temperature has descended to 110° ; if then any gas-bubbles are seen in the closed upper part of the test-tube the oil contains dangerous in- flammable vapors. As all vapors of petroleum are inflammable, it is not necessary to ignite them ; the demonstration of their presence in this way is sufficient to condemn such oil.
Raw Hide, To dissolve. — This can be done completely in water heated under pressure.
Resins, Solubility of. — Copal, amber, dammar, colophony, lac (or shellac), elemi, sandarac, mastic, and carnauba wax (a resin) have been experimented upon. Amber, shellac, elemi, sandarac, and mastic swell u^p and increase in bulk when heated ; the others fuse quietly. Carnauba wax melts in boiling water, colophony becomes pasty therein, while dammar, shellac, elemi, and mastic agglutinate. Copal, amber, and sandarac do not change in water.
Alcohol does not dissolve amber or dammar ; it agglutinates copal, and partly dissolves elemi and carnauba wax ; while colo- phony, shellac, sandarac, and mastic are readily soluble therein.
Ether does not dissolve amber and shellac ; it makes copals swell, and partly but slowly dissolves carnauba wax ; it readily dissolves dammar, coloi)hony, elemi, sandarac, and mastic.
Acetic acid does not dissolve amber and shellac ; it causes copal to swell ; it somewhat acts upon carnauba wax, but not at all \ipon any other of the resins above named. A hot solution of caustic soda, of sp. gr. 1.074, readily dissolves shellac, with difficulty colophony, and has no action upon the rest. In sulphide of car- bon, amber and shellac are insoluble ; copal swells therein ; elemi, sandarac, mastic, and carnauba wax are with difficulty dissolved, while dammar and colophony are readily so. Oil of turpentine has no action upon amber or shellac ; it causes copal to swell, and readily dissolves dammar, colophony, elemi, san- darac, carnauba, and very readily mastic. Sulphuric acid does not dissolve carnauba wax ; it dissolves and colors all other resins brown, except dammar, which becomes bright red. Nitric
188 pHactical technology.
acid docs not act upon the resins, but covers carnauba wax straw-vellow, elemi dirty yellow, and mastic and sandarac bright" brown. Ammonia does not dissolve some of these resins, but causes copal, sandarac, and mastic first to swell, afterward dissolving them ; colophony is easily soluble therein.
EuBBEK, Solvents for— These are ether (free from alcohol), chloroform, bisulphide of carbon, coal naphtha, and rectified oil of turpentine. By long boiling in water, rubber softens, swells, and becomes more soluble in its peculiar menstrua ; but when exposed to the air, it speedily resumes its pristine consistence and volume. Oil of turpentine dissolves caoutchouc only when the oil is very pure and with the ap])licati()n of heat ; the ordinary oil of turpen- tine of commerce cau.ses india-rubber to swell rather than to be- come dissolved. In order to prevent the viscosity of the india- rubber when evaporated from its solution, one part of caoutchouc is worked up with two ])arts of turpentine into a thin paste, to which is added + part of a hot conceatrated solution of sulphuret of potassium in water ; the yellow liquid formed leaves the caoutchouc perfectly elastic and without any viscosity. The solu- tions of caoutchouc in coal-tar, naphtha, and benzoline are most suited to unite i)ieces of caoutchouc, but the odor of the solvents is perceptible f:r a long time. Sulphide of carbon is the best sol- vent for caoutchouc. This solution, owing to the volatility of the menstrum, soon dries, leaving the latter in its natural state. When alcohol is mixed with sulphide of carbon, the latter does not any longer dissolve the caoutchouc, but simply softens it. and renders it capable of being more readily vulcanized. Alcohol also precipitates solutions of caoutchouc. When caoutchouc is treated with hot naphtha distilled from native petroleum or coal- tar, it swells to 30 times its foriiicr bulk ; and if then tritu- rated with a pestle and pressed through a sieve, it affonis a ho- mogeneous varnish, the same that is used in preparing the patent water i)roof cloth of Macintosh. Caoutchouc dissolves in the fixed oils, such as linsecd-oil, but the varnish has not the ]>roper ty of becoming concrete on exposure to thi' air. ('aout<^ho\ic melts at a heat of about 2m' or 2(50 aft.-r it has been nudted ; it does not solidity on cooling, but forms a sticky mass which does not l)ecome solid even when exposed to the air for months. Owing to this ])roj)erty, it furnishes a valuable material for the lubrication of stop-cocks and joints intended to n-niain air tight and yet be movable.
RlTHiiKU, To cut. — Dip the knife-blade in a ftolulion of caustic potash.
ViNK(i.\K, Making, from alcohol (.Xrtiis's process). — Dissolve^ oz. dry bichlorid.- of i)lalinuni in 5 lbs. of alcohol With this moisten li lbs. of charcoal broken to the size id a hazel-nut. ll<-at the charcoal in a covered criu-ible, and place it in the bottom of a vinegar vat. This (anses the rai)id oxiiiation of tin; a'^oh'd. Reheat the charcoal onc.t in 5 wiM-ks.
THE FARM.
FARM BITILDINGS.
Beams, Fastening in walls. — The usual custom of building the ends of floor-timbers into brick and stone walls is apt, in case of fire, to throw over the walls ; and resting the timbers on cor- bels interferes with the cornice-line below. By cutting the ends of the timbers on a bevel and laying in the wall, as in the annex-
SETTING BEAMS IN WAllS.
ed diagram, the cornice-line will not be broken ; and, in case of fire, the timbers will fall with little injury to the wall.
Blasting. — In small blasts, 1 lb. of powder will loosen about 4i tons of rock. In large blasts, 1 lb. of powder will loosen 2.} tons. 50 or GO lbs. of powder inclosed in a bag and hung against a barrier will demolish any ordinary structure. One man can bore with a bit 1 in. in diameter, fnjm 50 to 60 in. per day of 10 hours in granite, or 300 to 400 in. per day in limestone. Two strikers and a holder can bore with a bit 3 in. in diameter 10 ft. per day in rock of medium hardness.
Bricks from Gas-Coal Ashes.— These are of remarkable lightness, porosity, and dryness. Tlie ashes, after being taken from the retorts, are spread on the surface of a clean floor ; they are then finely pulverized, and 10 per cent of slaked lime, togeth- er with a small proportion of water, is intimately stirred and in- corporated with them. After a rest of 24 hours, the mixture is made into bricks by the ordinary process. The bricks are imme-
190 THE FARM.
diately transferred to the drying slit^ds, wliere a few days' expo- sure renders them fit for use.
Brickwouk, Preserving. — To exclude dampness, use the fol- lowing : f lb. mottled soap is dissolved in 1 gall, boiling water, and the hot solution spread steadily with a flat brush over the outer surface of the brickwork, care being taken that it does not lather ; this is allowed to dry for twenty-four hours, when a solution, formed of J lb. alum dissolved in 2 galls, water, is applied in a similar manner over the coating of soap. The soap and alum form an insoluble varnish, which the rain is unable to penetrate, and this cause of dampness is thus said to be effectually removed. The operation should be performed in dry, settled weather.
Another method is to use 8 parts linseed oil and 1 part sulphur, heated together to 278^, in an iron vessel.
Chimneys, Smoky, Causes of. — Want of sufficient height in the flue. The outlet of the chimney being jihiced in an exposed and cold situation, while the air with which the fire is supplied is drawn from a warmer and more sheltered re- gion. Excessive width in the flue, by which a large volume of cold air is drawn in and allowed to lower the temperature of the ascending column. Low temperature of the interior of the flue, in comparison with that of the external air. Humidity of the air. Too accurate fitting of the windows and door.s, and joints in the flooring. Tlie draft of one Are injuring that of others in the same house. A current caused by the heat of the fire circulating in the room. A flue of insufficient size. A foul flue. Displace- ment of masonry, or accumulation of mortar within the flue. The sudden obstruction of the draft, by gusts of wind entering the chimney-top. Increase of density of the air at the chimney- top, duo to the eff(M-t of wind in chimneys rising from the eav(?s of roofs. Drafts within the room which throw the smoke out of the influence of the ascending chimney current.
Chimneys, Smoky, Preventing efl'ects of. — A screen or blower of wire gauze, from ;j6 to 40 wires to tins inch, placed in front of range or stove lires, will prevent, it is said, smoke coming into the room when tlu^ cliimney fails to draw well.
CisTEHN, Building a. — One thing is essential, and is very ge- nerally neglected. It is to have tlui water as it comes into tiie cist(!rM conducted to tlie liottom. In this way, the water is en- tirely changed when it rains. When the fresli water simply pours in at tin; top, it immediatidy runs olT, and all tiu! nuiss of stagnant water remains undisturb(Hl, and soon becx)mea impure.
ClsTKKN Fii-TER. — .\ wall of Soft luirned bricks is well adapt- ed for tills i)urpos(!, wlien built up within the cist<!rn.
CoNCKKTE FoiJND.VTiONS, To build. — The concrete is c/mipos- (fd of lime, sand, wiitcr, grave], and round or lirolcen stones. A trench of l)oardH is first made, f)f the widtii of the desired foun- dation. Fill tlu! tnmcli witli the concrete to the depth of a foot or two, and let it stand until sullicitntly hard ; then add another footof concrete, and so go on, ad<Hng concrete and raising trench- boards as tlic Willi rlsrs.
THE FARM. IPl
CoNCKETE Pavements. — The cheapest material for mixing with gravel is coal-tar from gas-works.
Greenhouse, To build a cheap. — Mr. Peter Henderson says the ordinary span-roof is best. The walls are 4 ft. high, formed of locust or cedar posts. To the outside of these are nailed boards — rough hemlock will do, if appearances are not consid- ered. To the boards is tacked the ordinary tarred paper used by roofers. Against the paper is again nailed the outer or weather boarding. This makes really a better wall for greenhouse pur- poses than an 8-inch one of brick, as we find that the extremes of temperature of the greenhouse — inside at 50°, and perhaps 10° below zero outside — very soon destroy an 8-inch solid brick wall, particularly if exposed to the north or west. A wall of wood con- structed as above will last for twenty years, and be as good a pro- tection as one of 8-inch brick. The roof is formed by the ordina- ry sashes, 6 ft. in length by 3 ft. in width, which can be bought ready made. Heat with a flue not more than 60 and not less than 30 ft. in length ; if more, the flue would not heat it enough, and if less it would be likely to get too much heat. About 50 ft. by 11 is, we think, the best size of a greenhouse to heat with a flue. The flue should run all around the house — that is, it should start along under one bench, cross the end, and return under the other bench to the end where it begins, making the length of flue in a greenhouse of 50 feet about 110 feet long. It should have a " rise " in this length from the furnace of at least 18 in., to se- cure a free draught. For the first 25 ft. of flue nearest the fur- nace it should be built of brick, forming an air-space inside of about 7 x 7 in. From this point (25 ft. from the fire) the flue should be formed of the ordinary drain-pipe cement or terra-cot- ta. The former is to be preferred, and that of 7 or 8 in. diame- ter is best. The cost of a greenhouse thus built in the vicinity of New-York, is about $6 per running foot — that is, one 50 ft. long by 11 ft. wide costs $300.
Ice-House, To build an.—A house 12 ft. square by 8 or 9 ft. high is large enough for a good-sized family. It may be a frame building, entirely above the surface of the ground, and better if supported on posts, elevated a few inches, to be certain of good drainage. Build of joists, 3x3 in., with an outer boarding, hav- ing inside another series of uprights, also boarded, from 6 to 10 in. removed from the outer shell, with a solid floor of plank, the space between the two walls filled with tan, sawdust, straw or chaff, and a roof of good pitch. A drain for water should be made from the floor, and the space above the uprights, between a loose flooring and the pitch of the roof, filled with straw, hay, or some other dry, porous material. On the roof should be a venti- lator, the top defended from rain or snow. The ice should be packed in one solid mass, the sides not reaching the inner walls, but allowing a space of from 6 to 12 in. all around. The top of the ice should be covered with straw, and the door should be like the sides of the building, or double doors should be made, one in the outer and the other in the inner wall. Plant morning-glories or any other climbing plant about the building, and train them up over the roof, so that their foliage will serve as a protection against the sun.
19-2 THE FARM.
LiGHTNiNG-RODS, Valuable hints concerning. — Feather-beds are not a protection frona lightning. The human body is a better conductor of electricity than feather-beds or other objects ordinarily contained in the apartments of dwellings, and there- fore, when the lightning enters an apartment, the human body is likely to form one in a chain of inductions, determining the path of an electrical discharge, unless better conductors are in its vi- cinity to divert this action.
The only place of absolute security in a thunder-storm is an iron building ; or nest in safety is a building properly protected by lightning-rods.
A copper rod of one inch in diameter, or an equal quantity of copper under any other form, will resist the effect of any discharge of lightning hitherto experienced. The copper rod is therefore the safest and best material that can be used, but it is expensive. Iron rods of one inch in diameter are very commonly used, and, if pointed with solid copper and properly put up, are efficacious in the great majority of cases. The particular form of the rod makes no difference. It may be round or square, twisted or hol- low, composed of one solid piece or made of wires twisted to- gether. It is the quantity of metal contained in the cross-section of the rod that is of value, not the form.
Lightning-rods are provided with sharp points to allow the ac- cumulated negative fluid to pass off readily into the air and neu- tralize the positive fluid of the thunder-cloud.
The object being to make so good a passage for the lightning to the ground as to remove all danger of its leaping to some con- ductor in tlie house, the greatest care must be taken not to have any break in tlie conductivity. As it is inconvenient to manufac- ture or tran.^port the rods in one piece, the different parts must be in intimate connection when they are put up ; it is best to have them soldered, and the joints protected from the air and moisture.
The point of the rod should be extended a little above the chim- ney or highest part of tlie building, and should be fastened in contact with the l)uilding by stajjles or cleats. Glass insulators sliould not be emi)loyed. It nuikes no difference in conductivity whether the rod is painted or not painted.
No building can be said to be properly rodded or protected against lightning, unless the lower part of the rod or terminal ui\der the ground is made quite extensive. The extremity of the rod should connect with masses of good conducting materials, such as old iron, or iron ore, or coke, or charcoal, laid in trenches, or the rod itself should be elongated, sunk deep in the ground, and curried a considerable distance from the building, and juit in .•oiinection witli water, or moist earth if possible. Tlu' golden riiit- for safety is : " Provide the largest possible area of conduct- ing 8urfac(! for tlie terminal of the rod."
A lightning-rod which is not properly connected with the earth is quite dangerous. The very common method of merely stick- ing the lower end of the rod down into the dry earth near the surfa<-eof the ground is bail, and endangers the building, because dry earth is such ai)oor coiKluctor, and tlie amount of rod surface in contact witli the earth is so small I'nder such conditions, a portion of the electric current will be liktdy to find an easier path
THE FAEM. 193
to the earth, through the building than through the rod ; and a part of the electricity will therefore leave the rod, strike into the building, and down in various directions into the earth, making havoc as it goes. As a measure of prudence, house-owners should look to the terminals of their lightning-rods, and place there a considerable amount of the conducting materials above named.
It was supposed to have beeu established by Charles and Gay Lussac that a liglitning-rod protected an area whose radius was doulile the height of the rod extending above the building ; but this rule is no longer reliable, by reason of the extensive use of metals in the shape of pipes, etc., in the construction of the build- ings of our day.
When electricity finds several paths to the ground, it will pre- fer the best, it is true ; but some portion will also pass along the poorer conductors If, therefore, any metallic substances lie within the area supposed to be protected, they are in danger of being struck. This is especially true where the lightning has a chance to jump to the gas and water pipes of a building. It is a good plan to connect these pipes with the lightning-rod ; if the rod is struck, the electricity will then have an excellent path into the ground, and will be rapidly diffused over the vast underground network of pipes. The danger to the inmates of the house of being struck from these pipes is less than that of receiving a shock from the powerful induced currents liable to be developed in them, if unconnected, during a thunder-storm.
The more rods on a building the better, especially if all are connected with each other near their upper ends.
Finally, in the way of general advice, we would say: Connect all your lightning-rods together, and also to your iron tank, and water, gas. or other pipes, not by separate connections, but so that there is some connection between all, which connection should be as high up as possible. If you have a metal roof, connect all rods with it. If the roof is not of metal, then connect your rods to- gether by means of a good-sized conductor running along the ridge of the roof. Bear in mind that, to carry off the heaviest lightning-flash known, a copper rod one inch in diameter is not considered too large ; and though of course such flashes are of very rare occurrence, they may come. Hence the great value of uniting your different rods high up.
Mortar, Good weatherproof. — 3 bushels clean sand, mingled with I bushel good lime and i bushel cement, makes an excellent mortar which is not liable to be dislodged by storms.
Mortar, To make. — The lime ought to be pure, completely free from carbonic acid, and in the state of a very fine powder ; the sand should be free from clay, partly in the state of fine sand and partly gravel ; the water should be pure, and, if previously saturated with lime, so much the better. The best proportions are 3 parts fine sand, 4 parts coarse sand, 1 part quicklime recent- ly slaked, and as little water as possible. There should always be enough water added at first ; if water is added after slaking has begun, it will be chilled and the mortar lumpy. The addition of burnt bones improves mortar by giving it tenacity, and ren- ders it less apt to crack in drying.
194 THE FARM.
Oak Timber, Seasoning. — Oak loses about }; its weight in sea- soning, and about ^ its weight in becoming perfectly dry.
Pavement, Farmyard. — Make a concrete of gravel or sand and Portland cement ; or easier, of gravel, sand, coal-ashes, and coal- tar. Dig away the earth for 5 in., lay a bottom of pebbles as large as goose-eggs, ramming well down. Sweep off clean, and pay the surface with hot coal-tar, thinly ; ]iut on a coat of small er gravel previously dipped in hot tar, drained, and rolled in coal ashes with an intermixture of gravel. Roll it down as compact- ly as possible. Let the roller run slow, and let a boy follow it with a hoe to scrape all adherent gravel. Next, put on a coat of fine gravel or sand, coal-tar and some coal-ashes, to complete the surface. Roll again. This will take some weeks to harden, but will shed water, and eventually form a very firm surface. Do not use too much tar, but only enough to make the ingredients cohere under pressure.
R.\t-Pkoi)F Buildings. — The plan adopted in England is to have slate fioors, sawed and planed to uniform sizes and thick- ness. The walls are also covered with sawed or planed slates, well jointed and secured to the wall or studding with screws, wliich makes each room as secure against rats as an iron or stone box would be. The slate used for the fioor is from 1 to 2 in. thick, and that for the walls i in. thick.
Rat-Phook Frame Buildings. — Xail strips of board to the sill between each flooring joist, on the inside, reaching to the un- der side of the flooring planks or boards, and thereby covering the shelf formed by the sill between tlie joists. The idea is to allow the rats no place to stand upon while they are cutting through the floor.
Roads, Corduroy, To build. — First lay all small poles or brush transversely and across the road. Next take long trees — the smallest ends being at least 10 inches diameter — and ])lace them longitudinally across the poles, in two rows, 8 feet apart from centre to centre, making the ends at the junction of each ])iece lap each other at least 8 feet, breaking joint on either side, and jjlacing upon these ends large logs of sullicient length to ex- tend across the road, and 3 feet on each side of these stringers. Cover the stringers with transverse; logs, 12 feet long from scarf to scarf, and at least 10 inches in diamettir at the smallest end, fitted close together on tlu^ straight portions ; the logs alternated with a large and small end, and on the outer side of curves, all the large <;nds, wliieh will assist in the curvatur<>of the road and thr- gravity of the vehi<;les. Next, adze off" the centre ridges of thest; logs to a face of about 5 inches, for a width of 9 feet in the (■(!ntre of the roadway, and cover this 9 f«'et with gravel, to fill in between the; logs, and giv(; a smooth surface. A good plan is to lay on the top of the road thus formed poles of 5 or 0 inches in diameter, si)ilied down on each sidt^ of the track, every 10 f(;et, with oak i>ins, to jireveiit, in frosty weaiher, the lateral sliding of wagons.
RuoKiN<i, Pasteboard ami asphalt — This material is most suitable for fl:il roofs, having a fall of l.J inches to 4^ inches per
THE FARM. 19,-,
running foot. It may, however, also be used for roofs liavinjr .a greater fall, the expense being in this case somewhat larger tlian ior flat roofs, as the laying on is more difficult. Cover the roof first with dry boards, f incli to 1 inch thick, and not above 6 inch- es broad ; it more than ihe last-named width, or if not suffi- ciently dry, the boards ought to be split once before being laid on, in order to keep them from warping, and every board should be fastened with three nails at least on each of the rafters. The boards do not require to be rabbeted ; only those ends of the boards which form the eaves, by extending beyond tbe wall need to be joined in the said manner. In case of boards | inch thick being applied, the rafters f^hould not be moie than 2 feet from each other, as the boards may be too elastic and not strong enough to support the weight of the workmen, while the ronf will not be perfectly substantial.
The roofing may be done either from gable to gable, or from the eaves to the foot-ridge, the fir.-t roll being laid with a bend of 1 inch beyond the roof, and fastened with the flat-headed iron wire nails supplied for that purpose. The second roll is laid li inches over the first, and so on till the roof is covered. The joints and heads of the nails are then coated witli asphalt mastic, and the seams thus coated are strewed with dry sand. The whole roof is then coated with the mastic, and covered with sand. This coating, which is only to be effected in dry weather, renders the roof perfectly water-tight, and it can then, if desired, be painted or whitewasbed. A hundredweight of mastic covers a surface of 65 square yards. This process is in use in Copenhagen, Den- mark, and the roof weighs about ^ the weight of a tiled roof, and is substantial, resisting alike the influenceof water, fire, heat, and cold.
Roofing, Portland cement and tar. — The inclination of the frameworkr of the roof (which must have an even surface) should be at the rate of from + to | inch per foot. The rafters or joists should not be more than 2 feet 3 inches apart, S) as to give suffi cient strength. As the rafters rest on the side walls, a compara- tively small quantity of timber is required. Boards of 1 inch or IJ inch thick are fastened or nailed on the rafters, and should be dovetailed. These are then covered with a layer of sand i or i. inch thick, in order to produce an even surface. Strong brown paper, in continuous rolls, and as broad as possible, is then laid upon it, so that each length overlaps the other by about 4 inches. When the whole or a large part has thus been covered with pa- per, the mixture is put into a caldron, in the proportion of tar 100 pounds to Portland cement 180 pounds. Care must be taken to heat the tar gently, and to mix the cement with it gradually, in order to prevent its boiling over. This mixture of tar and ce- ment mtist then be laid on as hot as possible on the paper with a tar-brush. The next layer of paper is then laid upon it, and smoothed with a light wooden roller. In this way the whole roof must be covered. In order to break the joints of the paper, begin the second layer with half the breadth, and proceed as be- fore. The third and fourth layers are laid in like manner, with alternate layers of cement and" brown paper The last layer must be carefully covered with cement, and then strewn with sifted
196 THE FARM.
ash.es to the thickness of i inch. Next to the gutter is a board covered with zinc, and projecting about 3 inches. It should be laid on after the second layer has been completed, so as to be co- vered by the third and fourth. If there are any chimneys pro • jecting through the roof, they should be surrounded with zinc immediately after the first layer has been finished.
Roofing Zinc. — Permit perfect freedom to the sheets. Confine them nowhere, and separate lengths of guttering, and any other portions of a roof requiring to be made in long jneces, as much as possible. Eaves-gutters should be made in short lengths, bent in the direction of the way in which the sheet has been rolled and soldered, the solder being put between the sheets, and one sheet lapping over the other. Nor must they be screwed to the rafters, as this is a practice which occasions a constant failure in the joints of the iron eaves-gutters. Wherever a down-pipe conies, there should be a stopped end in the gutter ; and the gutter should not be continued longer than possible in one place. Where it is laid behind a parapet, a separate piece of flashing will dis- connect it wholly from the sheeting on the roof. For guttering, the gauge used should be increased in proportion to length ; there should be a proper substance in all cases. Oak boarding will spoil the zinc, and the fir boarding should be dry — tlie boards with an ajjerture of about ^ inch between each. If they are damp, as much oxidation will take place on the under side of the zinc as on top of it. From experiment, it appears that the oxidation proceeds for about four years, gradually diminishing after the first three months, when it hardens into a protecting coat of a dark gray color, preserving the metal beneath from fur- ther d£!terioration. A sheet of zincexjiosed to the atmosphere for a series of years loses little or nothing of its weight or thick- ness, and its surface remains hard and polished as enamel.
Shingles, To prevent decay of. — Put into a lar^e'tub 1 bar- rel of wood-ashes lye, 5 pounds white vitriol, 5 pounds alum, and as mucli salt as will di.ssolve in the mixture. Make the litpior quite warm, and put in as many shingles at a time as it will co- ver. When one batch of shingles is well soaked, remove and put in another. Tiien lay the shingles in the usual manner. With the li(juor that is left, mix enough lime to make white- wasii, and color witii lampblack, oclire, or Spanisli l)rown. Ap- l)ly to the roof with a brush or old broom. This wash may be renewed from time to time.
Shinoi.es, Painting. — Lay low-priced shingles — say from f2.7o to $4 ]H'r tiiousand — and i)aint {\u-m witli a coat of tar and asplialtum — say one barnd coal-tar, costing ^;J ; ten ))Ounds of asphailum at JJ cents, 'AO cents ; ten pounds ground slate, at 1 cent, 10 cents ; two gallons dead oil at 25 cents, 50 cents, which should \)t; added alter Dk- otlier has been wetted and tiioroughly mixed, 'i'liis mixture \^ as good as any tiling tluit can be put on to sliingles, as it will tliorouglily iteep llie, water out ; and, if dry, they will not rot under the lap, nor will the nails rust.
SiiATKS, Rooking, Selection of. — Dark purple and green slates are tlic; best for roofing ; others are liable to fade unequally, and produwi a disagreeahle appearance.
THE FARM. 197
Sled-Body, To build a transverse. — Make tke sills out of l-incli or f-inch boards, with oross-pieces of the same thickness bolted between the sills, which are double. You can make these very light and limber. Now put on your side-boards with a bolt down through the rave and sill, which will make it very stiff, and can be made very light, and with all the strength possible.
Smoke-House, Cheap and good. — For 50 hams, make dimen- sions 7x8 feet. Dig all the ground out to below the frost line, and fill up to the surface with small stones. On this lay a brick floor with lime mortar. Walls of brick, 8 inches thick by 7 feet high, and a door on one side, 2 feet wide. Door of wood, lined within with sheet-iron. For the top, put on joists, 2x4, set up edgewise, and 8^ inches from centre to centre, covered with brick and with a heavy coat of mortar. Build a small chimney over the centre, arching it over and covering it with a single roof in the usual way. An arch should be built on the outside, with a small iron door, similar to a stove-door, to shut it up. Make a hole in the arch through the wall of the house, and put an iron grate over it. The arch is much raore convenient to put the fire in, than to build the fire inside the house, and the chimney causes a good draught through the latter. Burn good corn-cobs or hickory wood. This house should cost about $20.
Stables, Building. — Bricks, built in hollow walls, are better than any other material. Commence with a stone foundation — the bottom course of which is broader than the stone-work above it — laid in half cement mortar up to the grade line, and then build the brick wall upon that, filling in all the space inclosed by the walls with concrete up to the line of the top of the water-table. Then pave with stones, firmly bedded to form a floor. On the outside, there should be a stone water-table, 8 or 10 inches high, projecting 1 or 2 inches outside of the main walls above, and having the upper surface of the projection beveled off to shed the water. Just above the water- table, it is well to have a course of slate built in the full thickness of the walls, which will prevent any dampness rising up into them from the ground by capillary attraction. Above the water-table, the walls should be built up with a smooth face, and with close, neatly struck joints inside as well as out, so as to present a clean, even surface, which should always be kept painted or washed with a lime or cement wash. Above the wall-plate, the space should be filled in to the under side of the root-boards. The ceilings over the main story should be lathed and plastered ; partly for the sake of the neat appear- ance, partly to keep away cobwebs which infest exposed beams, and partly to prevent foul air rising from the room below, and tainting the hay-loft. The doors and windows inside should be trimmed with architraves, even if the latter be merely strips of the cheapest stuff. It may be desirable to fur out and lath and plaster the walls of a stable ; but if this is to be done, it is better to wainscot with wood up to the height of, say 5 feet, and to fill in the space between the walls and the wainscot, as high as prac- ticable, with broken glass and mortar, and then to lath and plas- ter from the wainscot up to the ceiling. A wooden stable, too.
198 THE FAKM.
may witli advantage be treated in the same way, but the space behind the wainscot being wider, may be packed with bricks and mortar, and made solid in that way.
Timber, Strength of. — The strongest side is that which in its natural position faced the north.
Timber, To test the soundness of. — Apply the ear to the mid- dle of one of the ends, while another person strikes upon the op- posite extremity. If the wood is sound and of good quality, tlie blow is very distinctly heard, however long the beam may be. If the wood is disaggregated by decay or otherwise, the sound will be for the most part destroyed.
Trough, To make a tight. — Joint up the plank, and then, with a wide punch, set down a groove about ^^ in. deep the whole length ; then take off two or three shavings more, and put the trqugh together. When the wet gets into that joint the grt)ove swells out again just the thickness it was at first, and of course two or three shavings thicker than the plank, and so closes all up tight. Wood can also be ornamented by punching down carefully in patterns, planing ofE a little, and then wetting ; the parts punched down show in relief above the planed surface, and make quite a puzzle.
Water-Closet, To put up a. — The engraving represents sectional views of the water-closet in the upper floor of a two-story house. A A is the level of the surface of the ground at the back court and of the kitchen floor. B is a 6-inch vitrified fire-clay siphon-trap, with an open iron grating, C, at its top, which grating may be hinged. D is 4 inch soil-pipe fnmi the water-closet ; it is here sliown coming down inside the wall ; in other cases it may be carried down the outside. One advan- tage of snch pijies being carried down the inside is that they are more likely to be protected from frost. F is a ^-inch or 2-inch load pipe for ventilating the soil pipe. In this case, it is carried througli the wall ; in other cases it may be carried up through the roof, (i is tlie water-closet trunk, made of iron, it being a pan water-closet which is here shown. H is a finch h-ad pipe, carried through the wall, and put in to ventilate the trunk, or tliat sjjace between the wattT in the pan, I, or basin, J, and tlie water in the siplKm-traj), K. This J-incli ventilating i)ipe, H, is a very iini)ortant one, and its use ought to be th<^ rule in ])lace of the «'Xcei)tion, as is at i)r<-scnt the case. It works as follows : NN'lien the handle of the wati-r-closet is lifted, then any foul air lying in the trunk, in place of coming out into the apartment, is pent outside with a rush tlintugh this ]>il)e, 11 ; besides, being oj)en to the air, it tends to prevent tlie ac<-uinulatinn of such foul air in the trunk.
In order to kei-p the outer oritices of the i)ii)es, F and H, al- ways o|)en, it is a good plan to solder on one or two i)ieces of copper wire across tlieni. J is the water-closet basin, and the two small circles shown, underutatli K K.are the india-rubber i)ipeB. A li-inch zinc ventilating pipe may be carried up tlirough the roof to vr-niilate the space or inclosure in which the water-closet is situated. A gas-l)racket placed right below if will help, when lighted, to cautfc an upward current. The enqjly space at N is
TUE FAKM.
199
BUILDING ■WATER-CLOSETS.
supposed to be the water-closet window. O is the surface of the floor of the upper flat. No gas can accumulate in the soil-pipe, for the pressure of the atmosphere on the surface of the open grating, C, tends to send a current of fresh air through the soil- pipe and out at the ventilating pipe, F.
Water-Gate, a good. — This is an excell-nt device for fencing purposes over small streams. A gate, sliding in upright ways at the ends, like an old turnpike gate, has attached to the bottom board (a scantling is better, as not so likely to be broken in hisfh water) crutches which rest upon empty b irrels or casks. The up- rights at the ends of the gate are provided with friction-rollers, so that the jjate slides up and down easily in th * ways. Two or three casks will generally support the weioht of the gate, so that it descends nearly to the surface of, but does not enter, the water. A gate thus constructed will rise and fall with the stream, and is not liable to be washed away at high water.
Whiteavash, for outside work. — Take quicklime, i bushel ; slake, and add coiiinion salt, 1 pound : sulphate of zinc, i pound ; sweet milk. 1 ii:allon. Dissolve salt and zinc before add- ing, and mix tin- wlmli' to [iroper consistence with water.
2QQ THE FAUAt.
Wooden Buildings, To frame. — Particular attention should be paid to biiuliug the top of the walls well together. This is accomplished by framing the wall-plate all around the house, and spiking the ceiling joists down on the same ; then heriing- bone, bridging these joists in as many rows as are necessary to make a thoroughly stifE brace for the whole. The roof (no mat- ter whL^her Gothic or Mansard) can not exercise any bad influ- ence in pushing out the walls, when this system is adopted.
Wood To season and prevent warping.— Strip off bark, and bury about one foot deep in the spring, leaving in the ground for six months, and you will find no difficulty. This was the only wav by which the sapadillo or mountain mahogany in the Sierra NeVada could be seasoned, it being one of the hardest and most brittle kinds of wood known.
Windmill, To build a. — Windmills can be either horizontal or vertical, but the latter are almost exclusively employed. In the vertical windmill, the shaft is inclined to the horizon at an an"-le of from 5' to 15% when the wheel is placed at the top of a tower ; so that the wheel will clear the sides of the building, and allow space for the action of the wind. If the wheel is supported by a post, the shaft may be horizontal. The connec tion of the "shaft with the pump or other mechanism maybe made either with gearing or by means of a crank and connecting rod. The shaft must be free to swing around in any direction, BO that the wheel can always face the wind. It is moved, in the case of small windmills, by tlie use of a weather-van.: on tlie end of the shaft ojjposite to the wheel. With large windmills supported on towers, the top of the tower is generally arranged so that it can be rotated, and a small auxiliary wind-wheel, con- nected by gearing, moves it into the proper position as the direc- tion of the wind changes. The wheel of a windmill may be covered with cloth, or with slats of wood or metal, the cover in either case; being technically known as the sail.
Make the sail of a series of joined slats, that present a close surface to wind of tlui ordinary velocity, and open, thereby de- creasing the surface, as the velocity of the wind increases. The best velocity for a windmill is such that its i)friphiry moves about 2? tinies as fast as the wind. Thus, if the wind is moving at the rate of 20 feet a second, the tips of tlie sails sliould move at the rate of rti fe<'t a second, so that, if the wheel were 13 feet in diameter, it should make about 8:5 revolutions a minute. Of course, if the velocity of the wind varies greatly, it will be impossible to keej) the speed constant, so that windmills are not ordinarily well suited for work nHpiiring steady motion ; altlmngh they answer very well for nioviuij jiumps, if an intermittent supply of p(»wer is not a serious obstach-. in some sections, liowever, tlic i.revailing winds are (|uit.- steady, and in such nisi'S windmills ran Ix- iipplifd with advantage to grist-mills and f)th<'r useful work. The force and veicicity of tin- wind can only be determined by experiment, but the results of previous experimenters may be useful :
|
THE FARM. |
201 |
||
|
Velocity |
of wind. |
||
|
Perpendicular force, in pounds |
|||
|
In feet per |
In miles |
Common expressions of |
|
|
second. |
per hour. |
per square foot. |
the force of the wind. |
|
10 |
6.82 |
0.33 |
Gentle pleasant wind. |
|
20 |
13.64 |
0.91 |
Brisk gale. |
|
30 |
20.56 |
2.04 |
Very brisk. |
|
40 |
27.27 |
3.92 |
High wind. |
|
50 |
34.09 |
6.25 |
Very liigli. |
|
60 |
40.91 |
9.25 |
Very high. |
|
70 |
47.73 |
12.75 |
A storm. |
|
80 |
54.55 |
16.34 |
A storm. |
|
90 |
61.36 |
20.74) 25.28 1 |
|
|
100 |
68.18 |
A great storm. |
|
|
110 |
75.02 |
30.89) |
|
|
120 |
81.84 |
36.75 |
A hurricane. |
|
130 |
88.65 |
43.26 |
A hurricane. |
|
140 |
95.47 |
50.32 |
A violent hurricane. |
|
150 |
102.29 |
57.56 |
A violent hurricane. |
In the accompanying figure is shown one of the four sails of a windmill, it having been found that four sails of proper propor- tion produce the best effect. The piece P B is called the whip of the sail ; C D, E F, G H, etc., the bars of the sail. The bars are inclined to the plane of revolution at differ- ent angles, the angle made by any part of the sail with this plane be- ing called the weather of the sail. Making the distances A O, N L, L I, etc., •each equal to -^ of the diame- ter of the wheel, the best values for the angle of weather are as follows:
For N 0-18° For L M— 19° For J K— 18°
For G H— 16° For E F— 12i° For C D— 7°
The sail stretched over these bars will be a warped surface, some- what resembling the blade of a screw-propeller. The part B D 0, called the leading sail, is triangular, and B D is T5 of the diameter of the wheel, B C being tV. ^^^^ ^ ^' "i^ o^ the diameter. The main body of the sail, B C N O, is commonly rect- angular. A windmill of the best proportions, running under the most favorable circumstances, utilizes about -fi^^ of the energy of the wind that acts on an area equal to a circle having the same diameter as the wheel. It would not be -advisable to count on realizing more than half this power in general practice ; and on this assumption, we have the following empirical rule for
BtlTLDINO A WINUMELL.
202 THE FARM.
determining the diameter of a wheel to give a certain amount of power with an assiuneJ velocity of the wind :
Divide the required horse-power by the cube of the velocity of the wind in feet per second ; take the square root of the quotient and multiply it by the number 2024.8. The product will be the required diameter in feet. Example : A windmill is to be erected in a locality where the general velocity of the wind is about 20 feet per second. It is to be attached to a pump, the work re()uired of it being to raise 1000 gallons of water per hour through a height of 20 feet 1000 United States gallons of water weigh about 8320 pounds, and, taking into effect the re- sistance of ihe pump, the power required will be about f, of a horse-power, or 0.167 horse-power. Dividing this by 8000, the cube of tlie velocity of the wind, extracting the square root, and multiplying by 2024.8, we obtain S)^ ft. as the required diameter of the wheel, deferring to the figure, we find that, in this case, C N is 3 feet 10|- inches, B D, 7| inches, and B C, ll;,^^ inches. The velocity of the tips of the sales should be 52 feet per second, or the wheel should make about 108 revolutions a minute.
THE DAIRY.
Btttru, Philadelphia. — The pans containing milk to the depth of ;5 inches are set in flowing water, so as to be maintained at a temperature of about 58° Fahr. After siaudmg 34 liours, the milk is skimmed, and the cream ])ut in deep vessels of a capacity of about 12 gallons. It is kept at a temperature of 58' to 59' until it ac(|uiri's a slightly acid taste, wlien it goes to the diurn. The churn is a barrel rtivolving on a journal in each head, and is driven by horse-power. The churning occupies about an hour ; atid after tlie butti^rmilk is drawn off, cold water is added and a few turns given to the churn. The wiiter is then drawn off. This is rep(nited until the water as it is drawn otf is nearly free from milkiness. TIk; butter is worked with butter-workt^rs, a damp- ened cloth mcianwliile being pressed upon it to absorb the moisture and free it of buttermilk. Tlie cloth is frequently di])ped in cold water, and wrung dry during the jjrocess of wi))ing the butler. It is next salted at the rate of 1 ounce salt to ;{ pounds butter, thoroughly and evenly ineorp )rated by means of a butter- worker. It is then removed to ;i table, where it is weighi'd out and put into pound prints. After this, it goes into large tin trays, and is set in the water to harden, remaining until next niorniiig, when it is wra|)j)ed in damp cloths ancl placed upon shi'lves, oui- abovtMinother, iu tin lined cedar tubs, with ice in the compartments at the ends; and thiui it go(^B immi'diately to market. A I'liiladelphia Itutler di^aler says that, for tlm l»eHt butter, 'tlie cows ure fi'd on wliite clover and early mown meadow hay, cut fine; and mixed in with corn meal and wiieaten sliorts. No roots are fed, except carrots.
THE FARM. 203
Chttrning Milk, Temperature for. — 60° Fahr.
Cream-Gauge. — In a can 20 in. deep and 8 in. in diameter, cut a slot a few inches long. In this slot, insert a strip of glass, in grooves, and cement with white lead. Graduate the tin next to the glass. Set the milk in the can, and allow the cream to rise. The percentage may be seen on the glass and noted by the scale.
Cream, White specks in. — These are caused by too much acid in the cream. Cream should never stand in a room where the milk is set, but should be put into a cool place if you would avoid specks.
Cows, Care of. — Milk coming from ill-nourished, half- fed cows, having no surplus of food beyond minimum requirements of na- ture, is injurious, and may be a source of disease. Cows deprived of an abundance of good water, ventilation, and exercise, secrete impure and dangerous milk, which may be loaded with gases, animalculse and fever-germs. The milk from old, debilitated cows fed on grains or overstimulating food, is also imperfect and unhealthy to a variable degree. The nervous condition of thb cow at the time of milking determines the purity of the milk. If this is neglected, the milk is an active source of disease, and is positively dangerous and fatal.
Cow-Stables, Ventilation of. — Lay the floor of the stable upon a solid bed of earth and yravel, with a fall of 6 in. in 13 ft. from the stanchions, with the same ratio of descent, to a point for outlet of liquids. Make a platform raised 6 in. for the cows to stand or lie upon. The floor and platform plank should be bedded in water-lime mortar, so that there shall be no soaking down nor hiding-place for stale urine to deposit and generate venomous odors.
Milk, Poisonous sour. — Sour milk, after protracted exposure to the sun, develops a poisonous quality, sufficient to cause dis- ease and death to pigs fed thereon.
Milk, Setting. — Place the pans in cold water, which will pro- tect the milk from the acid until the cream has time to rise. For cream to rise readily on milk, set in cold water ; the atmo- • sphere in the room should be warmer than the water. There will as much cream rise on milk set in cold water in one hour as there will on milk not set in water in 24 hours.
Milk, Tainted. — Never allow dead animals to decay about a pasture, or any where near a barn or other localities inhabited by the milch-cows. The carrion odor is sure to affect the milk.
Milk, Testing for cream. — A simple method of determining the quantity of cream in any sample of milk consists in agitating the milk ina graduated glass tube with its bulk of ether for 4 or 5 minutes. Add alcohol in volume equal to that of the milk, and shake for 5 minutes. Place the tube vertically and allow it to rest lor a brief period, when the oily matter will rise to the surface so that its amount may be read off on the scale and the percentage easily computed.
Milk, To insure good. — The following questions Mr. X. A.
204 THE FARM.
Willard, a well-known dairy authority, recommends to be writ- ten out and posted about the dairy : " Do your cows feed in 8wam}3s and on boggy lands '? Have you good, sweet running water convenient for stock, and is it abundant and permanent in hot, dry weather? Have you shade-trees in your pasture, or do you think that cows make better milk while lying down to rest in discomfort in the hoi sun? Do you use dogs and stones to hurry the cows from pasture at milking time, thus overheat- ing their blood and bruising their udders ? Do you cleanse the udders of cows before milking by washing their teats with their own milk, and practice further economy by allowing their drip- pings to go into the milk-pail ? Do you enjoin your milkers to wash their hands thoroughly before silting down to milk ? When a cow makes a misstej) while being milked, do you allow your milkers to kick her with heavy boots, or to pound her over the back and sides with a heavy stool ? Is the air about your ' milk- barn' or milk-house reeking with the foul emanations of the pig-sty, the manure-heap, or other pestiferous odors ?"
Milk, To prevent souring by tluinder-storms. — A fire started in the dairy is an excellent preventive. This should be done even in the hottest weather. The object is to remove the damp, moist, heavy air, which is injurious to the milk.
Milk, To remove taste of turni])S in. — Give the cow no turnips for two or three hours before milking. It is better to feed only the centre of the turnip, cutting ofE the top and bottom. A tablespoonfiil of nitn^ dissolved in as much water as it will take to a gallon of milk, placed in the pail before milking, is said to remove the taste of the vegetable.
FARM ITTNTS AND RECIPES,
Bee Moths, To kill. — Bee moths can easily be killed in large numbers l)y setting a pan of grease, in which is a floating ignited wick,n(^arth(! hives after dark. The moths will fly into the light and fall into the grease.
Bones, Reducing. — Place them in a larg(! kettle tilled with ashes, and about one peck of lime to a barrel of bones. Cover with water and Imii. In 24 hours all the hones, with the excep- tion, perhHi)S, of the hard shinlxmes, will heconie so much soft encd as to i)e easily ])uiveri'/ed by hand. They will not be in particles of bone, but in a pasty condition, and in an excellent form to mix with muck, loam, or ashi-s. Hy boiling the shin- hones 10 or 12 liours longer, they will also become soft.
Hones. Value of. as a (ertili/,<T.— 100 Ihs. of dry bone-dust
add to the soil as i h organic animal matter as ;!00 lbs. of
Mood or flesh, and al.soai the same time • their weight of inorganic matter- lime, magnc'^ia, common salt, soda, and i)hos|>lioric acid. Superphosphate of lime, commonly nr^ed liy farmers, is simply
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bones treated witli ^ their weight sulphuric acid and an equal quantity of water.
Carbonic Acid Gas, Removing from wells, cisterns, etc. — (1.) A bellows with a rubber hose reaching near the bottom will soon blow out the gas. (2 ) Let down a large bucket, draw up and empty tlie gas as if it were water. (3.) Pour down water ; do this when a person falls to the bottom from inhaling the gas. (4.) Let down an umbrella spread, and pull up quickly several times in succession.
Caterpillars, Exterminating. — Orchard or tent caterpillars leave their rings of eggs on the young twigs. If these are cut off with a clipping pole, it will prevent in every instance a large nest of caterpillars, and be much more easily done than after the latter have grown.
Caterpillars, Remedy for. — A solution (1 part in 500) of sul- phide of potassium, sprinkled on the tree by means of a hand-sy- ringe, is extensively used in France.
Celery, Propagation of. —A deep trench should first be dug, at the bottom of which a layer of sticks of wood, say 6 in. thick, should be placed a drain-pipe being placed endwise upon one or both ends of the Jayer. The sticks should be then covered with about a foot of ricli mouxd, wherein the plants should be set in a row, and about 5 in. apart. The plants should be well watered, the water being supplied through the drain-pipes, so that, pass- ing through the layer of sticks, which serves as a conduit, the wa- ter is supplied to the roots of the plants. In earthing up, care should be exercised to close the stems of the plant well together with the hand, so that no mould can get between them. The earthing process should be performed sufficiently frequently to keep the mould nearly level with the leaves of the outside stems. If these directions are carefully observed, the plant may be grown at least 4 ft. in length, and this without impairing the flavor.
Charcoal, Effect of, on flowers. — All red flowers are greatly benefited by covering the earth in their pots with about an inch of pulverized charcoal. The colors (both i-ed and violet) are rendered extremely brilliant. Yellow flowers are not affected in any way by charcoal.
Chickens, To fatten. — The best food for this purpose is Indian meal and milk.
Chinch-Bugs, To destroy. — Put old pieces of rag or carpet in the crotches of the trees attacked. When the worms spin, as they will, in the rags, throw the latter in scalding water. The bugs can thus be killed by wholesale.
Cider Barrels, To clean. — Pour in lime-water, and then in- sert a trace-chain through the bung-hole, remembering to fasten a strong cord on the chain so as to pull it out again. Shake the barrel until all the mould inside is rubbed off. Rinse with wa- ter, and finally pour in a little whisky.
Cider Casks, To prepare.— Cider should never be put into new casks without previously scalding them with water containing salt, or with water in which apple-pomace has been boiled. Beer-
206 THE FARM.
casks slioiild never be used for cider, nor cider-casks for beer. Wine and brandy casks will keep cider well, if the tartar adher- ing to their sides is first carefully scraped oft and the casks be well scalded. Burning a little sulphur in a cask will effectually remove must.
Cider from apple-parings. — The parings of a bushel of apples will yield 1 qt. of cider by the aid of the hand-press.
Cider-Making, Hints for. — 1. No- good cider can be made from unripe fruit. The nearer to perfect ripeness the apples, the bet- ter the cider. 2. No rotten apples, nor bitter leaves, nor stems, nor filth of any kind should be ground for cider. 3. Two presses are really necessary for each mill, so that the pomace can be ex- posed to the air in the one, while it is being pressed in the other, and thus acquire a deeper color. 4. New oak barrels, or those in which whisky or alcohol has been kept, are the best. 5. If more color and richer body are desired, a quart or two of boiled cider to each barrel will impart them.
CiDEK, Purifying. — Cider may be purified by isinglass, about 1 oz. of the latter to the gallon. Dissolve in warm water, stir gently into the cider, let it settle, and draw off the liquor.
Cider, To preserve sweet for years. — Put it up in air-tight cans, after the manner of fruit. Rack it off the dregs, and can before fermentation sets in.
Coal- Ashes as a fertilizer. — Mix them with a small propor- tion of well-rotted horse-manure, sifting the ashes first, and you will have an excellent fertilizer.
CoRN-CoBS, Utilization of. — Save the corn-cobs for kindlings, es- pecially if wood is not going to be plentiful next winter. To pre- pare them, melt togetlier 6U parts resin and 40 parts tar. Dip in the cobs, and dry on sheet-metal heated to about the temperature of boiling water.
Doos, Bed for. — The best is newly made deal shavings. They will clean the dog as well as water, and will drive away fleas.
Dust, Road, Value of. — During a dry season, every country resident should secure several barrels of road-dust. Tliose who keep poultry may secure by its use a valuable fertilizer, nearly as strong as guano, with none of its disagreeable odor. Place an inch or two of roiul-dust in tlu! bottom of a barrel; tiuMi, as the poultry liousc is ri'giilarly cleaned, deposit a layer an inch thick of the cleanings, and so on, alternately layers of each till the bar- rel is full. The thinner each layer is, the more perfect will be the intermixture of the ingredients. If the soil of which the road-dust is made is clayey, tlu^ layers of eacli may be of equal thickuf^SH ; if sandy, th(! dust slioiiM be at least twice as tliick as tli(! layer of drop|)ings. Old Ijarnds of any kind may be used for this |)nrpose, but if previously soaked witli crude; petroleum or coated with gas-tar, tlu^y will last many years. If the contents are |K)iin(ied on a floor into fine powder befont applying, the; fer- tilizer may be sown from a drill. Ifoad-diist is one of the most, perfect deodorizers of vaults — converting their contents also into rich manure. I'lace a l)arrel or b«>x of it in the closet, with a
THE FARM. 207
small dipper, and throw down a pint into the vault each time it is occupied, and there will be no offensive odor whatever. This is simpler, cheaper, and better than a water-closet, and never freezes or gets out of order. Mixing the road-dust with equal bulk of coal-ashes is an improvement, making the fertilizer more friable.
Fertilizer, A cheap. — This consists of sulphate of ammonia, 60 lbs. ; nitrate of soda, 40 lbs. ; ground bone, 250 lbs. ; plaster, 250 lbs. ; salt, ^ bushel ; wood ashes, 3 bushels ; stable manure, 20 bushels. Apply the above amount to six acres. Labor in pre- paring included, it costs about $15. It is said to give as good results as most of the commercial fertilizers costing $50 per ton.
Fish-Net, To preserve from decay. — Steep in melted paraffine.
Fowls, Fattening. — It is said that charcoal will fatten fowls, and at the same time give the meat improved tenderness and flavor. Pulverize and mix with the food. A turkey requires about a gill a day.
Fruit, To preserve. — Fruit is kept in Russia by beincp packed in creosotized lime. Tlie lime is slaked in water in which a little creosote has been dissolved, and is allowed to fall to powder. The latter is spread over the bottom of a deal box, to about one inch in thickness. A sheet of paper is laid above, and then the fruit. Over the fruit is another sheet of paper, then more lime, and so on, until the box is full, when a little finely powdered charcoal is packed in the corners, and the lid tightly closed. Fruit thus inclosed will, it is said, remain good for a year.
Fallen Leaves, To utilize. — These should be carefully gath- ered, as they are excellent to mix with hot-bed material. They do not heat so rapidly as stable-manure, and in this have an ad- vantage, as tempering the violence makes manure last longer and maintain a more regular heat. They are excellent material to put round cold frames to protect half-hardy plants. A board is put up to the height of the frame boards, and about a foot or more from them, and the leaves filled in between. If the plants are somewhat tender, the bottom of the frajnes may be filled in a few feet with the leaves. Fallen leaves, after having been two or three years decaying, make admirable stuff for potting plants and for flowers in general.
Grafts, Cutting and storing. — There is no better time to cut grafts, than at the commencement of winter. lu cutting and packing them away, let them be labeled. For this purpose they should be tied up in bunches, not over 2 or 3 inches in diameter, with 3 bands around each bunch — at the ends and middle. The names may be written on a strip of pine-board or lath, ^ in. wide, j-ij in. thick, and nearly as long as the scions. This, if tied up with the bunch, will keep the same secure. For conveni- ence in quickly determining the name, there should be another strip of lath, sharp at one end, and with the name distinctly written on the other, thrnst into the bundle with the name pro- jecting from it. If these bunches or bundles are now placed on end in a box, with plenty of damp pioss between them and over the top, they will keep in a cellar in good condition, and anvsort
208 THE FARM
may be selected, and withdrawn without disturbing the rest, by reading the projecting label. It is needful, however, to keep an occasional eye to them, to see that the proper degree of moisture is maintained — which should be just enough to keep them from shriveling, and no more.
Gkapes, To ripen. — In the Rhine district, grape-vines are kept low and as near the soil as possible, so that the heat of the sun may be reflected back upon them from the ground ; and the ripening is thus carried on through the night by the heat radiated from the earth.
Gr.vsshoppers, To utilize. — The grasshoppers, desiccated and ground, are useful as a fertilizer ; but in this prepared condition, they form an excellent food for all insect-feeding birds. There is no better food for all young domestic fowls. Containing silicic acid in a soluble state, they seem specially adapted for young birds, promoting the growth of feathers.
fxRASsiNf; A Sr-OPE. — A steep* slope may be grassed over with- out sodding by first smoothing the surface and then mixing a tough paste or mortar of clay, loam, and horse-manure, with suffi- cient water. The grass seed, which should be a mixture of Ken- tucky blue grass and white clover, should be thickly but evenly scattered upon the moist surface of this plaster as it is spread upon the bank. Tiie plaster should be at least one or two inches thick, and a thin layer should be laid over the seed. The surface should be k(;pt moist, and a light dressing of some active ferti- lizer would help the growth. In a few weeks the growing grass should be cut, and should be kept short at ail times until a tliick sod is formed.
(jiliAN'O, Handling. — Many cases of iioisoiiiug hiive occurred by contact of guano with wounds. It should be handled with gloved hands.
Gr.wo, Home-made. — Make a compound of 1 bushel ashes, 2 l)U8he8 fowl-tnanure, 1^- bushels jjlastcr, and 4 bushels muck. Spread the muck on the barn-Hoor and dump tlie fowl-manure on top of it. Pulverize the latter with the spade, and mix in the otlicr ingredients. Moisten the heap with water, or, better, with urine, l)ffore planting. Deposit alxtut a handful in each hill of corn, potatoi's, or beans, mixing it with tin; soil before putting in the seed.
IIakness, Cleaning. — Unbuckle all the i)arts and wash clean with soft water, .soap, and a brush. A little tur])entine or benzine will take off imy gummy substance which the soaj) fails to re- move 'I'heu warm tiie leather, and, as soon as dry on the sur- face, apply the oil with a paint-brush or a swab. Neat's-foot oil is the bi;8t.. Hang up thi! harness in a wiirm place to dry, but do not let it burn.
H MfNK-^-;, Oiliu!,''. — (live on« .)r two coats of lampblack and castor-oil warmed sulIiciiMitly to make it peiietiate the stock rea<lily. Then spongc! the harnesH with 2 (jts. warm soap-suds ; when dry, rub over a mixture of oil and tallow, e(|ual parts, with enough Prussian blue to give color. When well rubbed in, this coiMpoiiiid leuves a smooth, (dean surface.
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Harness, Working- team. — Do not use martingales on working teams. See that the hames are buckled tight enough at the top t(; bring the draft-iron near the centre of the collar. If too low, it not only interferes witli the action of the shoulder, but giTes the collar an uneven bearing.
Hay, Spontaneous combustion of. — Hay, when piled damp and in too large masses, ferments and turns dark. In decomposing, sufficient heat is developed to be insupjjortable when the hand is thrust into the mass, and vapors begin to be emitted. When the water is almost entirely evaporated, the decomposition continues, and the hay becomes carbonized little by little ; and then the charred portion, like peat — peat-cinders mixed with charcoal, sul- phurous pyrites and lignite, etc. — becomes a kind of pyrophorus, by virtue of its great porosity and of the large quantity of mat- ter exposed to high oxidation. Under the influence of air in large amount, this charcoal becomes concentrated on the surface to such a degree that the mass reaches a temperature which re- sults in its bursting into flames. The preventives for this danger are care that the hay in the lofts is kept perfectly dry, that it is well stacked, and that it is stored in small heaps rather than in large masses.
Hay, To estimate the weight of. — Allow 1 cwt. of hay to the cubic yard.
Horse, Power of. — The greatest amount an average horse can pull in a horizontal line will raise a weight of 900 lbs. ; but he can only do this momentarily ; in continued exertion, probably half this amount is the limit.
Horses, Bedding for. — Sawdust serves this purpose well.
Horses, Buying, Hints for. — Examine the eyes in the stable, then in the light ; if they are in any degree defective, reject. Exa- mine the teeth to determine the age. Examine the poll or crown of the head, and the witliers, or top of the shoulders, as the former is the seat of poll evil, and the latter that of fistula. Examine the front feet ; and if the frog has fallen, or settled down be- tween the heels of the shoes, and the heels are contracted, reject him, as he, if not already lame, is liable to become so at any moment. Next observe the knees and ankles of the horse you desire to purchase, and, if cocked, you may be sure that it is the result of the displacement of the internal organs of' the foot, a consequence of neglect of the form of the foot, and injudicious shoeing. Exauine for interfering, from the ankle to the knees, and if it proves that he cuts the knee, or the leg between the knee and the ankle, or the latter badly, reject. " Speedy cuts" of the knee and leg are most serious in their effects. 5lany trotting horses, which would be of great value were it not for this single defect, are by it rendered valueless. (.'arefuUy examine the hoofs for cracks, as jockeys have acquired great skill in concealing cracks in the hoofs. If cracks are observable in any degree, re- ject. Also both look and feel for ringbones, which are callosities on the bones of the pastern near the foot ; if apparent, reject. Examine the hind feet for the same defects of the foot and ankle that we have named in connection with the front feet. Then proceed to the hock, which is the seat of curb, and both
210 THE FAKM.
bone and blood spavins. The former is ft bony enlargement of tlie posterior and lower poi'tion of the hock-joint ; the second a bony excrescence on the lower, inner, and ratlu-r anterior portion of the hock ; and the last is a soft enlargement of the synovial membrane on the inner and upper portion of the hock. They are either of them sufficient reason for rejecting. See that the horse stands with the front feet well under him, and observe both the heels of the ft-et and shoes to see if he " forges" or overreaches ; and in case he does, and the toes of the front feet are low. the heels high, and the heels of the front shoes a good thickness, and the toes of the hind feet are of no proper length, reject him ; for if he .still overreaches with his feet in the condition described, lie is incurable. If he props out both front feet, or points them alternately, reject. In testing the driving qualities, take the reins while on the ground, invite the owner to get in the vehicle first, then drive yourself. Avoid the display or the use of the whip ; and if he has not sufficient spirit to exhibit his best speed without it, reject. Should he drive satisfactorily without, it will then be proper to test his amiability and the extent of his training in the use of the whip. Thoroughly te.st his walking qualities first, as that gait is more important in the horse of all work than great trotting speed. The value of ahorse, safe for all purposes with- out blinds, is greatly enhanced thereby. Purchase of the breeder of the horse if practicable ; the reasons are obvious.
Houses, Common-sense treatment for. — (1) All horses must not be fed in the same proportions, without due regard to their ages, constitutions, and work. (3) Never use bad hay because it is ch(!ap ; there is no nourishment in it. (3) Damaged corn brings on inflannnation of the bowels and skin diseases. (4) Cliaii'is better for old horses than hay, because they can chew and digest it better. (5) Mix chaft" with corn or beans. (U) There is not sutlicient nutritive body in either hay or grass alone to support a horse under hard work ; in such case the food should chiefly be oats. (7) For a .saddle or a coach horse, half a jieck of sound oats and 18 lbs. of good hay is sufficient ; if tlie hay is not good, add a (juarter of a peck more oats. (8) Hack feeding is wasteful ; feed with chopped hay from a nuinger. (9) Sprinkle the hay with water that has salt dissolved in it, becau.se it is jtleasing to tlie aiiiinai's taste and more easily digested. A teaspooiiful of salt in a l)ucket of water is sutlicient. (lO) Oats should be bruised for an old horse, but not for a young one. (11) Cut grass should always be given in sjjring to horses that can not be turned out into the fields ; it is very cool and refreshing. (12) Water horses from a pond or stream, rather tiian from a si)ring or well, because' tlie water from the latter is generally hard and <'o]d, while the former is soft and comparatively warm. 'I'lui liorse prefers soft muddy water to liard water, though never so dear. (13) A lior.'if! should liave at least a pailful of water morning and even- ing, or (still better) four lialf pailfuls at four several times in the day. because this assuages his thirst without bloiiting him. He sbould not be made to work directly after a full draft of water. (M) ]>o not allow a liorse to have warm water to drink, since, if he lias to drink cold water after becoming accustomed to
THE FARM. 211
warm, it will give him colic. (15) Do not work a horse when he refuses food after drinking ; he is thoroughly fagged out.
Horses, Dead, To utilize. — Drag the body to some out-of-the- way part of the farm and sprinkle quicklime over it. Then cover with about twenty-five wagon-loads of muck or sods. In a year an excellent manure-heap will be at your disposal. Smaller ani- mals may be similarly utilized.
Horses, Scratches on. — These may be cured by washing the legs in warm, strong soap-suds, and then in beef brine.
Horses, To keep flies from. — Make an infusion of 3 hand- fuls of walnut leaves in 3 qts. of cold water. Let this stand over night and boil for a quarter of an hour in the morning. When cold, rub it over the ears, neck, and other irritable parts of the animal, with a moist sponge.
Horses, Wounds on. — If suppuration is inevitable, use car- bolic acid combined with glycerine or linseed-oil in the propor- tion of 1 to 20. It may be applied night and morning with a feather. The wound must be kept clean, and, in the case of backs and shoulders, all pressure removed by small pads of curled horse-hair, sewed on the harness above and below the sore.
Ice, Compressed. — Thin ice from ponds, or small pieces left after cutting blocks from larger bodies of water, may be stored in a profitable manner, and at the same time its preservation in- sured, by compressing it into solid blocks by means of any simple press. In localities where ice is not attainable, snow might easily be treated in the same way.
Ice, To keep. — Select a shady spot, on the north side, if possible, of a clump of trees. Throw up a circular mound, some 12 in. in height and at least 15 ft. in diameter, flattening the summit care- fully, and leaving a trench around the eminence, 2 ft. in width and 18 in. in depth. In gathering the ice, there is no necessity of cutting into uniform shape or of seeking large pieces. Fill up the carts with any kind of fragments, transport them to the mound, and dump them on a platform made of a few planks. Ram the surface of the mound hard and firm, cover with sawdust, and then place the first layer of ice, which should previously be cracked into small pieces, for which purpose the men should be provided with wooden mallets. As each layer is put on the stack, the ice should be thoroughly pounded, both above and at the sides, so as to form a huge block of ice, the shape of which will be slightly conical.
When the stack is completed, it will require two coverings of straw, one lying upon the ice and the other supported on a wooden framework about 18 in. outside the first covering.
The layer of straw next the ice must be well beaten and flat- tened down upon it, and when this is done, be 12 in. in thickness. The framework, upon which a similar thickness of straw is placed, may be formed by inserting stout larch or other poles of a suitable length round the base in a slanting direction, so that they can be readily brought together at the top, and securely fastened with stout cord. From six to eight of these will, when joined together by means of strips of wood fixed about 13 in. apart, aflEord ample
212 THE FARM.
support for tlie second covering of the straw. Tliis must be put on nicelj, so as to prevent the possibility of the rain's penetrating to the inner covering. By this arrangement there will be a body of air, which is one of the most effectual non-conductors known, between the two coverings of straw. To effect a change of the inclosed air, when rendered needful by its becoming charged with the moisture arising from the melted ice, a piece of iron or earth- enware piping a few inches in diameter should be fixed near the apex, one end being just above the straw, and the other end reaching into the inclosed space. The pipe can be readily opened or stopped up, as may appear necessary, but as a rule it will suf- fice to open the pipe once a week, and allow it to remain open for about two hours. This should be done early in the morning, as the air is then much cooler than during the day or in the even- ing.
In removing ice from the stack, the early morning should be taken advantage of, because of the waste which must naturally ensue from a rush of warm air at midday. That removed can be placed in a cellar, or even an outhouse, and be enveloped in saw- dust until required. The ice must be taken from the top ; and when tlie fir.st supply is obtained, a good (juantity of dry sawdust should be placed over the crown.
Insect-Catching Device, A simple. — Cover the inside of an old tub with liquid tar, and at twilight put a lighted lantern with- in, leaving the whole out over night. The bugs, attracted by the light, try to reach the lantern, and are caught and held fast by the tar.
Insects on Plants, To discover. — If the leaves of the ])lant seem reddish or yellow, or if they curl up, a close inspection will generally disclose that the plants are infested by a very small green insect, or else with red spider, either of which must be de- stroyed. For this purpose, scald some common tobacco with wa- ter until the latter is colored yellow, and when cold, sprinkle the leaves of the ])lants with it. It is a gootl plan to pass tiie stems and leaves of the plants between the fingers, and to then shake the ])lant and well water the bed iinnKnliately afterward ; the lat- ter operation destroys a large proportion of the insects shaken from the plant.
Insects, To i)rotect cattle from. — Hub a very weak solution of carbolic acid through the hair.
MANtiKi:, Salt as. — Salt should never l)e applied other than in a ]>ulveroiis state, and never employed on impervious, cold, and hu- mid soils. Tlie best manner to use it is to combine it with other manures, a dose of 2 cwt. to the acre being sutRcieUt. When selected to destroy insects, it should bo applied before sunrisi!. In the casc! of cerr-als, suit strengthens tlie stems, and causes the ears to fill iietter, and favors the dissolution and aesimilation of the ])lios]>hates and silicates. It acts vigorously on potatoes, and can be <lelected in tlu^ir ashes to the extent of on*! half or one per ciuit. Asparagus is a verital)le glutton in tlie |)reHenee of salt. .A <lose of '.'> cwt. j)er acre acts without fjiil on beet, injuring its value for sugar ])nrposi-s hut enhancing it for tlie fi'eding of cattle. <'td/,a has as marked a predilection for sail
THE FARM. 213
as asparagus ; and in Holland, where the culture of peas is so ex- tensive, salt is something like a necessity. Mixed with hay in the proportion of 4 ozs. to 1 cwt., the fodder is more appetizing ; but the best way to feed it to animals is to allow them to enjoy it in the form of rock salt.
Manure, Soot. — Save the soot that falls from the chimneys, when the latter are cleaned. Twelve quarts of soot to a hogshead of water makes a good liquid manure, to be applied to the roots of plants.
Manure. — The bodies of king crabs, often found along the sea- shore, when decayed and mixed with sawdust, straw, muck, or similar material, make an excellent manure. Land so poor that no wheat could be grown on it, has been so enriched by the appli- cation of this compost, that from 25 to 30 bushels to the acre have been raised.
Moss ON Trees, To destroy. — Use a whitewash of quicklime and wood-ashes.
Mowing Machines, Draft of. — The power required to drive a mowing machine at work may be resolved into direct draft and side draft. A good mowing machine should be so balanced be- tween the driving wheels and the cutter bar, by placing the line of draft nearer or further from the heel of the bar, that ordinarily there will be little or no side draft. If so placed, the end of the tongue will sometimes, when at work, be drawn toward the stand- ing grass, and sometimes thrown away from it by the side draft. Practically, side draft is of small account in a good machine. The direct drait depends upon three causes, and may be resolved into three parts : 1, The draft of the machine itself, on its own wheels, on the ground ; 2, The power required to give motion to the gear- ing and the knife ; 3, The resistance offered by the grass or other substance cut. The power required to draw the machine on its own wheels depends upon the size of the wheels, the perfection of the axles, and the smoothness of the ground, and, other things being equal, upon the weight of the machine ; and in a machine weigh- ing 600 lbs., should not, on a smooth firm turf and level field, be more than 75 to 100 lbs Adding to the weight of the machine would add to the draft just in proportion, whether that added weight be in the machine or in a driver on it. Suppose the ma- chine to weigh 600 lbs. and the draft to be 80 lbs., put a driver of 150 lbs. on the seat, and you have increased the draft 25 per cent, or to 100 lbs., while the power required to drive the knife and to cut the grass remains unchanged, and you have only increased the draft 20 lbs. The power to drive the knife and gearing de- pends upon the perfection of the gearing and the weight and velocity of the knife. A machine that in proper order may not require more than 10 or 20 lbs. of power, may require ten or twenty times that amount from deficiency of oil, collection of dirt in the gearing, gum on the knife, or loosening of the connections of the pitman by wearing or otherwise. The resistance of the grass to be cut will vary with every change of condition, kind, and thickness of grass, and every variation in the condition of the knife and rapidity of stroke. The greater the velocity of a cut- ting edge, after the velocity is once obtained, the less power is
214 THE FARM.
required to do a given amount of work. The direct draft of a good marhine, working under the most favorable circiuusiances, has been determined by experiment to be less than 300 lbs. ; but tliose favorable conditions are not always to be obtained, so that tlie draft must many times be much heavier. The jiower of a machine to cut, other things being equal, depends upon the hold the wheels have upon the ground ; when the second and third causes combined are sufficient to overcome the hold the wheels have, the latter t^lide, the knife stops, the machine is clogged. The heavier the machine, the less likely this is to occur ; putting a heavy driver on the seat will sometimes carry a macliinc through when with a lighter one it would clog. When the knife readies the end of the stroke, its momentum is considerable, and it re- quires nearly as much power to stop it as it did to start it to ii.ake the stroke ; it would require quite as much if it were not for the loss of some power by the friction of the knife in the guards. Now if the joints of the pitman and connections are all perfect, this stopping occurs when the crank passes the centre of the shaft driving it, and the remainder of the momentum of the knife is expended upon the crank in the direction of its length and at right angles to the driving power, so that none of that is used up in stopping the knife. But if these joints of the pitman are loose, so that there is a little play, and the crank can pass the centre be- fore the knife reaches the end of the stroke, this momentum will be expended in opposition to the driving power, and will of course increase the power necessary to work the machine by so much as is necessary to overcome the momentum of the knife ; again, the crank beginning to act upon the knife after it has passed the cen- tre to make the return stroke, the knife must start with a greater velocity, causing another loss. Xow, put the same machine into the grass, and the grass operates to stop the knife as soon as the crank allows it to stop, thus saving the momentum that was ex- pended upon the crank in ojiposition to the driving jiower. and also shortening the stroke and saving power that way. Supj)i)8- ing, to illustrate, that there is a play of ^ inch in the joints, tlien the knife running out of the grass will be thrown to the extreme length each way, and will add 1 inch to the length of the stroke, increasing the i)owcr necessary to make it. If it re(|uires a cer- tain number of pounds power to make a stroke ot 3 inches in length, it will require 33^ per cent more power to make a stroke of 4 inches in length in the same time. ^Vhenever these amounts of power lost in this way equal the power required to cut the grass, tlien the machine will draw just as heavily out of the grass as in it. From these premises many deductions nuiy be made as to tlie care and practical use of mowing machines.
Nkst Kfu;s, To make. — Take an f)rdinary hen's cfXiS, break a small hole in tlie small end, about ji of an incli in diameter, ex- tract the <-ontents, and, after it is thoroughly dear inside, till it with i)o\vdered slaked lime, tamping it in ordiT to inaki^ it con- tain as much as possible. After it is full, seal it up witii jilasti-r o' Paris, and you have a nest egg which can not he distinguisiied by tile hen from tlu; other eggs, and one which will not crack (like otlier aggB) by being frozen.
THE FARM. 215
Onions, To transplant.— Plant them tightly in the soil, with the leaves pointing to the north. When thus placed, after the vegetables take root, the sun will draw the stalks vertical.
Oxen, Food consumed by. — An ox will consume 2 per cent of his weight of hay per day to maintain his condition. If put to moderate labor, an increase of this quantity to 3 per cent will en- able him to perform his work and still maintain his flesh. If he is to be fatted, he requires about 4^ per cent of his weight daily in nutritious food.
Painting Boats. — Boats should be painted with raw oil. Boiled oil used in the paint is very apt to blister and peel from the wood.
Paris Green, To use. — In using Paris green to exterminate the potato bugs, the poison should be mixed with the cheapest grade of flour, 1 lb. green to 10 lbs. flour. A good way of applying it to the plants is to take an old 2 quart tin fruit-can, melt off the top, and put in a wooden head in which insert a broom-handle. Bore a hole in the head, also, to pour the powder in, and then punch the bottom full of holes about the size of No. 6 shot. Walk alongside the rows, when the vines are wet with dew or rain, and make one shoot at each hill.
Pastures, Seeding. — Select varieties of seeds that spring up in succession, so that a good fresh bite may be had from spring to fall.
Pear Culture. — Pears have a tendency to crack when the trees stand in soil which is deficient in lime and potash. Com- mon wood-ashes contain these salts nearly in the proportions that pear-trees on such soil require — 40 per cent of potash and 80 per cent of lime. By applying wood-ashes at the rate of four hun- dred bushels to the acre, after the fruit had formed and cracked, the disease was totally eradicated by the next season.
Peat, Estimating quantity of. — Peat, as ordinarily in the bed, will weigh from 2100 to 2400 lbs. per cubic yard ; and if drained in the bed, 1340 to 1490 lbs.; and air-dried, 320 to 380 lbs., when it will be found to be reduced to about i or ^ its original bulk.
Peat, Facts concerning. — When saturated with salt water, peat is generally unfit for heating purposes. The fine, clay-like pow- der found underlying peat-beds, of a yellowish white color, is composed of shields of infusorial animalculjB, and forms a supe- rior powder for polishing metals. In working a bed of peat, the first step will be to ascertain if drainage is necessary ; and, se- condly, how it can be effected and at the least cost. If the bed can not be economically drained, resort must be had to mechani- cal excavation. It is best not to drain a bed below the level to which you can effectually work out in a season, unless you can close the outlet drain to allow it to fill again with water for the winter, for the reason that drained peat that has been frozen is apt to disintegrate after thawing, and become impoverished for a solid homogeneous fuel. Peat that has been well manipulated and dried for fuel rarely holds more than 10 per cent of moisture, and it will not afterwards become saturated with water, even by immersion for an entire winter. A cubic yard of closely-packed
216 THE FARM.
peat fuel will weigh from 1630 to 2180 lbs., and the heating value of 1 lb. of such peat is equal to even 1^ lbs. wood ; one cord of f/ood wood will weigh almost 4200 lbs. , and 1 cord of peat fuel will weigh about 3750 lbs., showing a gain in space as well as in greater heating power.
Plants, Creeping, Pegging down. — To propagate lobelias and verbenas, the first bloom should-be picked off, and the branches, as they extend, should be pegged down closely to the surface of the mould. The branches will then take root as they lengthen, and by thus drawing a large amount of sustenance from the soil, they will bloom very freely and cover a large space. A verbena may thus be made to cover a square yard, and a lobelia a square foot of ground.
Plants, Iron and ashes for. — Wliite flowers, or roses, that have petals nearly white, will be greatly improved in brilliancy by providing iron sand and unleached ashes for the roots of growing plants. Ferruginous material may be applied to the soil where flowers are growing, or where they are to grow, by procuring a supply of oxide of iron, in the form of the dark-colored scales that fall from the heated bars of iron when the metal is hammer- ed by tlie blacksmiths. Iron turnings and iron tilings, which may be obtained for a trifle at most machine-shops, should be worked into the soil near flowers, and in a few years it will be perceived that all the minute fragments will have been dissolv- ed, thus furnishing the choicest material for jiaintiiig flie gayest colors of tlie flower-garden. If wood-ashes can be obtained readi- ly, let a dressing be spread over the surface of the ground, about lialf an inch deep, ami be raked in.
A dressing of quicklime will be found excellent for flowers of every description. It is also of eminent importance to imj)rove the fertility of the soil where flowers are growing, in order to have mature, plump, ripe seed. Let the foregoing materials be spread around the flowers, and raked in at any convenient period of the year.
Plants, Potting. — Tlie mould for potting should be light and loamy, tlie fertilizing material used being well decayed. If the soil is rich of itself, it is belter to be eitlier very sparing with the fertilizer or to dispense with it altogether. In tlu; bottom of tlie put )»lace sfveral small broken pi(!ces of crockery or similar ma- terial to assist tli(^ drainage ; and in setting the i)liint, be canfiil to kee]) it well down in the pot, and to press the mould moderately around the roots. Tlie surface of the mould should be about half !Ui inch billow the level of the top of the flower-pot. Slijis should lie planted close to the sides i)f the ]wi, and in small i)ots. When a ]ilaiil becomes ])ot-l)oun(l, that is, when the roots have become nialted around the sides and bottom of the ])ot, tlie ])lant, so soon as it has ceased blooming, should be re-iiotted in a larger ]iot. It is not neressfiry to remove any of th»> mould from the roots, but siiii])ly to All in tlie space in the larf^er pot with new and rich mould.
I'la.\T-1'i<()I1.( Toit, A newspaper.— A convenient number of newHpajw'rs may be; jiasted together, and the edges folded over strings, thus making a screen whidi, susi)endod ovisr tlie newspa-
THE FARM. 217
pers spread loosely over the plants, would give the young shoots an excellent protection in the severest cold weather, and from the sun's rays in summer.
Plants, Selecting. — Choose those whose leaves are of a deep green, and in all cases those which are short and bushy, and have no bloom upon them. If, however, they are in bloom, cut off thti flowers before pUmting, which will only delay the bloom- ing a -tew days, and wiU greatly strengtheu the plant. If the plants have been reared in a greenhouse or under frames, keep them a few days before setting them in beds, placing them out of doors in the daytime, and taking them in at night, in order to make them hardy and prevent them suffering from the cool night air. If the plants ar^' placed in a cold-frame, either before or after being planted in the beds, be careful to lift the frame during a great part of the daytime, otherwise the moisture which gathers on the inside of the glass will fall upon the plants and infallibly kill them by what is called dampness.
Plants, Treating unhealthy. — Mr. Peter Henderson, the cele- brated horticulturist, says : Whenever plants begin to drop their leaves, it is certain that their health has been injured either by over-potting, over-watering, over-heating, by too much cold, or by applying such stimulants as guano, or by some other means having destroyel the fine rootlets by which the plant feeds, and induced disease that may lead to death. If the roots of the plant have been injured from any of the above-named causes, let the soil in which it is potted become nearly dry ; then remove the plant from the pot, take the ball of soil in which the roots have been enveloped, and crush it between the hands just enough to allow all the sour outer crust of the ball of earth to be shaken off ; thi'U re-pot in rather dry soil (composed of any fresh soil mixed with equal bulk of leaf-mould or street-sweepings), using a new flower-pot, or having thoroughly washed the old one, so that the moisture can freely evaporate through the pores. Be careful not to over-feed the sick plant. Let the pot be only large enough to admit of not more than an inch of soil between the pot and ball of roots. After re-potting, give it water enough to settle the soil, and do not apply any more until the plant has begun to grow, unless, indeed, the atmosphere is so dry that the moisture has entirely evaporated from the soil ; then, of course, water must be given, or the patient may die from the opposite cause — starva- tion. The danger to be avoided is in all probability that which brought on the sickness, namely, saturation of the soil by too much water.
Potatoes, Hoeing. — By drawing up the earth over the pota- to in sloping ridges, the plant is deprived of its due supply of moisture by rains, for when they fall the water is cast into the ditf'hes. Further, in regard to the idea that, by thus earthing up, the number of tubers is increased, the effect is quite the re- verse ; for experience proves that a potato, placed an inch only under the surface of the earth, will produce more tubers than one planted at the depth of a foot.
Potato Sprouts, Poisonous. — The sprouts of the potato con- tain an alkaloid, termed by chemists solanine, which is very poi-
21?! THE FARAr.
sonous if taki'u into the system. Tl does not exist in the tubers unless they are exposed to light and air, which sometimes occurs from the accidental removal of tlie cartli in cultivation.
Potatoes, Stoi-incr. — A plan, tested successfully for eight years, is to si)rinkle the floor with fine unslaked lime, over which a layer of potatoes 4 or 5 inches in depth is spread. Then sprin- kle again witli lime, and add another layer of potatoes the same depth as before, and thus continue till the whole are disposed of. The lime used is about one fortieth part by measure of the pota- toes.
Potatoes thus treated have never become infected with disease, and when disease was already existing it has not spread ; besides which, tlie quality of the potatoes has been rather improved than otherwise by the treatment, especially where they were watery or waxy.
PorLTKV-lIousES, Purifying. — Lime is an excellent purifier, and, when carljolic acid is added to the whitewash, willeflectually keep away vermin from the walls. After every cleaning of the floor it should be sprinkled Avith carbolic acid ; dilution, twenty of water to one of acid. This is one of the best disinfectants and antiseptics known, and is not used as much as it deserves. The roosts should be sprinkled with it every week. This whitewash- ing should be done twice at least, better three times a year. The nests of sitting hens should be s])rinkled with carbolic acid to keep off vermin ; and the; coops also, where young broods are kept for a time, should l>e purified in this way. If a hen gets lousy, the dilute acid will destroy the lice, if put under the wings, and on the head and neck. Wood-ashi'S are excellent to be kept in fowl-houses for hens to dust themselves with. They are much more effectual than sand, but sand should also be kept for a bath.
Phopagating Plants. — To ])ropagate geraniums and calceo- larias, do not let the plants flower too soon, but pinch off the first appt^aring l)loom, and pinch out the eyes of all straggling branches, which will immediately thr.>w out side-shoots, thus forming very healthy and strong as well as good sha]>ed plants. Givfi l)referen<f to thost^ plants Avhicli liave their liranches close to the surface of the soil.
Pkunino Tukks. — The iJropcT cut is called the " clean cut," and is made by cutting at an angh; of 45 , beginning at th(^ back of the bud, and finishing slightly above it. When pruned in this way the wound readily and raj)idly heals, and coinmeiuu^s tobe covered with new wood as soon as the young bud i)ushes into growth. I'runing should always be dmn- with a keen edged knife, holding the shoot in the left han<l, and making one sliar|), (piicU ilriiw. 'J'lie operation should be delayecl until the middh^ of February, and jM^rfornied Ijetween tliat time and the niiildh^ of Marcli.
li.XTH, Kxterniination of, by bisulphiile of carl)on — In.sert a lead pipe into llii^ iioles, and ]>our in Ijisnlphide of carbon. This should only be usckI out of doors, nev(!r in buildings. An ounce and a half of tlie li(|nid is sullicient to pour in at a tiin<\ Where there are several holes near together, slop all but tlie Olio in wliich the bisMlphide is ])oui('(l, with bricks.
THE FARM,
219
Red Si'iDEKS, To extermiuate. — Syringe the plants freely with water once or twice a day, taking care to wet the under side of the leaves. Keep the air of the room moist, by setting pans of Avater on the flues, heating-pipes, or register ; give all the light possible, and ventilate freely whenever tlie weather will permit. When the soil is dry, give sufficient water to moisten «all the soil in the pot, and water no more until the surface is dry again. If plants seem stunted or sickly, repot them in fresh, rich soil, or use some other means to induce a healthy growth. The red spi- der is any thing but an aquatic insect, and will yield to the hy- dropathic treatment if it is persisted in.
Sand is the best substance in which to preserve carrots through the winter. It should be perfectly dry. It will keep the roots crisp and prevent softening.
Spawn-Carrying Device. — The apparatus represented here-
FISH-SPAWN CARRYING APPARATUS.
with is a new invention of Mr. Seth Green. It consists of a sim- ple wooden box, of a convenient size to be carried in the hand by means of tlie handle above. Its joints are covered with tin. Inside are numerous small trays made of wood, covered below with can- ton flannel. The upper tray, shown in the foreground, is pro- vided with a hinged cover of the same materials. The spawn is
220 THE FARM.
placed upon tlie bottom of the trays, together with moss or sea- weed, and kept moist. The temperature of the room may be so regulated that the spawn can be hatched in from 50 to 150 daya. Bnidk-troiit, salmon trout, white-fish, and sahnon-eggs have beei) irausported with success, over long journeys, by this means.
Skeds, Germination of. — The germination of seeds can be watclied at every stage of its progress by laying tlie seeds between moist towels and placing the latter between plates. The towels can be lifted without damage to the tender sprouts.
Seeds, Vitality of. — Seed Vvili not germinate if they are too old, and disappointment and delay often result. Experience of seedsmen indicat< s that, if properly gathered and i)reserved, beans will retain vitality 2 years , beet, 7 ; cabbage, 4 ; carrot, 2 ; sweet corn, 2 ; cucumber, 10 ; lettuce, 3 ; mebjn, 10 ; onion, 1 ; parsnip, 1 ; peas, 2 ; radish, 3 ; squash, 10 ; tomato, 7 ; turnip, 4.
Sheep, To protect from dogs. — An old sheep-raiser says that the most efhcacious ])l;in is to ])rovide 15 <»r 20 sheep, in a flock of 100, each with a globular bell about the size of a teacup.
Sleigh. — The length of the double whiffletree and the neck- yoke for a sleigh should be just as long as the sleigh is wide from the centn; (^i one runner to the other.
Slugs, Rose, To destroy. — Wood-ashes must be sifted on early in the morning while the leaves are damp, the branches being turned over carefully, so that the under sides of the leaves, to which the young slugs cling, may get their share of the siftings. If the night has hwn dew less, in order to make the work tho- rough, first sprinkle the l)ushcs, and the ashes will then cling to the slugs, to their utter destruction.
Stu.mps, Clearing oflE. — In the autumn, bore a hole 1 to 2 inch- es in diameter, aceording to the girth of the stump, vertically in the centre of the latter, and about 18 inches deep. Put into it from 1 to 2 ozs. saltpetre ; fill the hole with water, and plug up close. In the ensuing spring, take out tlie plug, pour in about | gill kerosene oil and ignite it. The stuni]) will smoulder away, without blazing, to the very extremity of the roots, leaving no- thing but ashes.
Stables, To remove rank snu-ll of. — Sawdust, wetteil with sul- |)huric acid, diluted with 40 ])!irts of wafer, and distributed about horsc! stables, will remove; the disagre.ahle aninioniacal smell.
Suii-SoiL Dii.MN, A simple. — An exctdlent subsoil drain may be made by digging a trench, ami fillinu^ in the bottom with sticks of wood, compressing them together with tlie feet, and then covering them with the mould. The effect! vene^s of .such a drain will endure for several years, and the final decay of the wood will serve to euriili the soil.
Si'MAc, ('ulti vatir)n and jireparation of. — Sunuic is largel\' used in tanning the liner kinds of leather, esjx'cially in the manufac- ture of the hard-grained nioniccf».s and similar goods. It is also einploycid as th<; base of many (X)lorH in calico and (hhilni print- ing. 'I'Ik! only trouble is in curing it ]>roperl\ . This must be doiu! with all the care that is bi'sfowed upon tobacco or hop.s. Exposure, aftiT cutting, to a heavy dew injures it, and a rain-
THE FARM. 221
Storm detracts materially from its value. It is cut wlien in full leaf ; and when properly dried is ground, leaves and sticks toge- ther. An acre in lull bearing will produce not less than three tons ; and when fit for market, it is worth from eiglity to one hundred dollars a ton. The manufacturers, as the curers are called, pay one cent a pound for it in a green state. The Com- missioner of Agriculture advises to plant in rows, in order to cul- tivate between, either by seed or cutting of the roots. We should advise cuttings by all means, as sumac is as tenacious of life as the blackberry or horse-radish. It will never need but one planting, and the crop can be gathered any time from July to the time of frost. If it is cut later in the season, and annually, the leaves and the stocks can be ground together. If the cutting is delayed until the stock has formed into solid wood, the leaves must be stripped from the stock, and the stock is thus wasted. It is doubtful if any thing is gained in the weight of leaves after the middle of July, at which time almost every tree has completed what is called first growth for the season.
Sumac, Mordants for dyeing with. — The mordants used for dyeing with sumac are either tin, acetate of iron, or sulphate of zinc. The first gives yellow, the second gray or black, according to strength, and the third greenish-yellow.
Tools, Paint for. — White lead ground in oil, mingled with Prussian blue, similarly prepared, to give the proper shade, and finally mixed with a little carriage-varnish, is an excellent and durable paint for farm-machinery and agricultural tools.
Trees, Felling. — To find the height at which a tree must be cut, so that its top will strike a given point on the ground : Square the height of tree, and the given distance from tree to point. Divide the difference of these squares by twice the height of tree, and the quotient will be the height from the ground Avhere the tree has to be cut. Example : Height of tree =60 feet, distance of point to the tree 20 feet ; then 60^=3600, 30-==400, difEerence=3200. 3200^(2x60)=26.6 feet.
Trees, Fruit, To protect against mice. — Apply to the bark a mixture of tallow, 3 parts, tar, 1 part, hot.
Trees, Girdled, To save. — If possible, bank up earth about the trunk to above the level of the girdle. If the wounded parts are too high, bind on clay with a bandage. The sooner the sur- face is protected after injury the better. The death of the tree is caused by the seasoning of the sap-wood.
Trees, Young, in hot weather. — If the trunk is fully exposed to the sun, it should be protected from intense heat. A couple of boards, tacked together like a trough and set up against the trunk, will furnish the required shade ; or the trunk may be bound with a hay-rope, or be loosely strawed up as for winter protection.
Trichina in Pork, A cause of. — It has lately been found that swine may become infested with trichinse through eating carrion, or even decayed vegetable substances. This is a point worth consideration by farmers who incline to the belief that dead
222 THE FAKM.
chickens, putrid swill, or any otlier filth, about the place, is legi- mate food for the pig.
TuRNiBS, To protect from fly. — Use lime, slaked just before application. Sow it by hand over the plants ; or sow brimstone with the seed. A simple way of removing the insects from the plants is to mount a board two feet square on wheels, cover the under side of the board with tar, and straddle it over the rows, drawing it from end to end of the latter. The insects will jump oil on the pitch and be caught.
Watekkall, To determine the height of, in a running stream. — A small temporary dam, unless one exists, must be made, so as to secure a still surface. Take two poles, sufficiently long to reach from the bottom of the water to the required line-level. Make a plain mark or notch on both sticks, at a distance from the upper end equal to the distance of the intended line- level above the water, marking that distance in feet and inches. Push the poles down through the water into the earth at the bottom until the notches are both at the level surface of the water, care being taken to have the poles plumb and at a convenient distance apart. Sight across the tops of these two, and set as many more as may be desired to run the line of level to the desired jjoint, and the tops being ranged accurately by the first two, will show a water- level so many feet above that of the water. It is estimated that this is a more accurate way than the use of the ordinary spirit- level.
Water for Fisii-Ponds — Lead-pipe will not do to conduct water to fish-ponds. It is likely to poison tlie fish.
Weeds, Destroying. — Some weeds can be killed and prevented from growing in garden-patlis, by watering the ground with a weak solution of carbolic acid, 1 part pure crystallized acid to 2000 parts water. Sprinkle from a watering-pot.
Worms, C'irrant and Goosereruy, liemedy for. — The best is powdered white hellebore, obtainal)le at any druggist's. Put the powder in a common tin cup, tying a juece of very fine muslin over the mouth. Fasten the apparatus to the end of a short stick, and dust the powder througii tht; musliu lightly upon the bushes. Do not work on a windy day, and ."^tand to windward during the operation, as, if taken into the nfj.'^trils, the hellebore excites violent sneezing. The Bame material is a good remedy for cucumber-beetles.
HOUSEHOLD HINTS.
Ants, Red, To drive away. — Sprigs of wiutergreen or ground ivy will drive away red ants ; branches of wormwood will serve the same purpose for black ants. The insects may be kept out of sugar-barrels by drawing a wide chalk mark around the top, near the edge.
Aquarium, To make and stock an. — One of tlie first principles, in constructing a tank for an aquarium, is to give the water tlie greatest possible exposure to the air. The simple rectangular form is the best. This is generally constructed of iron and glass ; the iron should he japanned, and the glass be Freucli plate, to insure brilliauey and strength. The breadth and height of the tank should be about one half of the length. Cheap tanks can be made of wood and glass, the frame and bottom being of wood, and tlie sides of glass. In order to make the joints watertight, care must be taken to" get a proper aquarium putty or cement. The following is a good retipe : Put an eggcupf ul oil and 4 ozs. tar to 1 lb. resin ; melt over a gentle fire. Test it to see if it has the proper consistency when cooled ; if it has not, heat longer or add more resin and tar. Pour the cement into the angles in a heated state, but not boiling hot, as it would crack the glass. The cement will be firm in a few minutes. Then tip the aqua- rium in a different position, and treat a second angle likewise, and so on. The cement does not poison the water. It is not ad- visable to make the aquarium of great depth ; about eight inches of water is sufficient. In regard to the light, great care must be taken. Too much often causes blindness, and is a common source of disease. The light fish receive in rivers comes from above, and an aquarium should be constructed so as to form no exception to this rule. All cross-lights should be carefully avoided, at least if the light is very strong. Never place the aquarium in front of a window so that the light passes through it ; for, when viewing an aquarium, the source of light should come from behind us. Not enough light is as injurious as too much, and causes decay of the vegetation. Having constructed a watertight aquarium, the bottom is strewn over with clean sand to the depth of 1 to 3 inches ; on this a little gravel is spread ; then a few stones or rock-work. Heavy large rocks should be avoided ; they displace a large amount of water, and in- crease the danger of breaking the glass sides. Pumice-stone, well washed, is the best kind, being light and with a rough surface suitable for the rooting of plants, etc. ; and if fancy forms are desired (bridge- work, etc.). the pumice-stone can be cut quite easily to the desired shapes. The plants are rooted in the sand and the vessel left at rest for a week for the plants to vegetate. The fol- lowing plants will be found useful : Utricutaria inflata, utricu-
224 HOUSEHOLD HINTS.
Inria vulgaris, myyiopJiyUum spicat <m, anarcharis Canadensis, and hottoida ii'flutii.
In obtaini^Ag' plants, procure all the roots and see that they are well rooted. If fungus should form, add snails {planorbis tricol- cis) ; they will completely destroy it. After the plants are well started, add the shells and amphibious animals. The following shells will be found desirable : Planorbis trivoldis,physa hetero- stiiipha, uiiio complanatus. Many shells are not needed. Snails act the part ot scavengers ; and where the different elements of an aquarium are rightly balanced, two or more snails will be found sufficient.
If amphibitjus animals are Introduced, the rock-work must ex- tend above the surface of the water, or a float of some kind must be substituted. It is impossible for them to live under water all the time, and they would die without some such arrangement.
The turtles claim lirst rank. The enys punctatu, or spottel water-turtle, and the clivysemys pieta, or painted water-turtle, will be found to be the best for the aquarium, and should be pro cured when very young, as they are very destructive when old. The tritons {triton tiyrinus, triton iiiger), the red salamander, the ciay-fish (/(.stttctis B(trtoni), are all suitable, and present a very odd and yet a very natural look to the aquarium.
In selecting the fishes, a few only thrive in confinement. Among these, and the first, is the gold-fish. He can live for months without introduced food, and is, without comparison, the most hardy, standing remarkable changes in the tem])eratur(! ; and he is the most gaudy and attractive. A large number of the fishes prey upon each other, and will only do for the aquarium when in the young state. Among these may be mentioned pomo- tis vulgaris, or sun-fish, csoxretir.ulatus, or common pickerel, and j)erca Jlorcsccns, or yellow perch. The leuciscus pyi/nnfus, or roL-k- fish, is a great addition, and is found very plentifully in our streams. The jyimdvdus atrarius, or common black catfish, is another worthy of a i)lace. So also is the hydr((rgia diaphana, or transparent minnow. But few fish can live in an atiuarium, and the needless crowding together, so often seen, is very hurtful to healtli, and causes sound, strong fisli in a short time to become weak and j)oi>r. The great difiiculty in keeping an aciuarium is to secure enough oxygen for the fish. To a slight degree, it is the duty of the plants to su))])ly this ; but if too much vegetation be present, decomposition takes place and ruin follows. It has been demonstrated that only a small amount is necessary to absorb the carboni<' aciil given off by the fish and anii)liibians ; conseiiuently, if tlni water be daily ai'-rated with a syringe, it will absorb an abundant hupply of oxygen for the animal life, and the trouble arising from the decay'of much vegetable matter will be lessened or altogether avoided,
AciUAUlU.M, To mend broken glass of an. — Fasten a strip of glass over the crack, inside the aquarium, using for a cement white sludlac dissolved in ^ its w<ight of Venice turpentine.
AwNlNOH, WATKitruoOKiNf}. — Dip first in a solution contain- ing 20 per cent soap, and afterwards in another solution contain- ing the same percentage of copper. Wash afterwards.
1
HOUSEHOLD HINTS. 225
Benzole, Necessity of care in use of. — Benzole is often em- ployed for removing grease-spots. It is highly volatile and in- tiammable ; so that the contents of a 4-oz. phial, if overturned, will render the air of a moderate- sized room highly explosive. Never handle it near a fire or light, as the tiame, igniting the vapor from an uncorked bottle, will leap over to the latter, often over a distance of several feet.
Bites, Rattlesnake, Remedy for. — The following is used by soldiers on the plains, and is said to be efficacious : Iodide of potassium, 4 grains ; corrosive sublimate, 2 grains ; bromine, 5 drachms. Ten drops, diluted with a tablespoonfiil or two of brandy, wine, or whisky, is the dose, to be repeated if necessary. Keep in a well-stoppered phial.
Boot Jelly and Shirt Coffee. — Some time ago. Dr. Vander Weyde, of New-York City, regaled some friends not merely with boot jelly, but with shirt coffee, and the repast was pronounced by all partakers excellent. The doctor tells us that lie made the jelly by first cleaning the boot, and subsequently boiling it with soda, under a pressure of about two atmospheres. The tannic acid in the leather, combined with salt, made tannate of soda, and the gelatin rose to the top, whence it was removed and dried. From this last, with suitable flavoring material, the jelly was readily concocted. The shirt coffee, which we inciden- tally mentioned above, was sweetened with cuff and collar sugar, both coffee and sugar being produced in the same way. The linen (after, of course, washing) was treated with nitric acid, which, acting on the lignite contained in the fibre, produced glu- cose, or grapi' sugar. This, roasted, made an excellent imitation coffee, which an addition of unroasted glucose readily sweetened.
Boots, Waterproofing. — Use a piece of paraffine candle about the size of a nut, dissolved in lard-oil at 140° Fahr. Apply once a month.
Boots, To stop squeaking of. — Drive a peg into the middle of the sole.
Boots, Wet. — When the boots are taken off, fill them quite full with dry oats. This grain has a great fondness for damp, and will rapidly absorb the least vestige of it from the wet leather. As it quickly and completely takes up the moisture, it swells and fills the boot with a tightly-fitting last, keeping its form good, and drying the leather without hardening it. In the morning, shake out the oats and hang them in a bag near the fire to dry, ready for the next wet night ; draw on the boots, and go happily and comfortably about the day's work.
Bottles cont.aining Resinous Solutions, To clean. — Wash with caustic alkaline lyes and rinse with alcohol ; if they have held essential oils, wash with sulphuric acid and rinse with water.
BOTTLFS, Sealing. — Gelatine mixed with glycerine is used for this purpose. This is liquid while hot, but an elastic solid when cold.
BoTTi-ES, To cut in two. — Turn the bottle as evenly as possi- ble over a low gaslight fiame for about 10 minutes ; then dip
226 HOUSEHOLD HINTS.
Steadily in water, and the sudden cooling will cause a regular crack to encircle the side at the heated phice, allowing the por- tions to be easily separated.
Bottles, To prevent breakage in packing. — Slip rubber rings over them.
BUHNS, Remedy for. — White lead rubbed to a paste in linseed- oil. Another good remedy is as follows : Take the best white glue (extra), 15 ozs. ; break it into small pieces, add to it 2 pints cold water, and allow it to become soft. Then melt it on a water-bath, add to it 2 fluid ounces glycerine and 6 drachms carbolic acid, and continue the heat on the water-bath until a glossy, tough skin begins to form over the surface in the inter- vals of stirring. The mixture may be used at once, after the glue is melted and the glycerine and carbolic acid are added ; but when time allows, it is advisable to get rid of a little more of the water, until the proper point is reached. On cooling, this mix- ture hardens to an elastic mass, covered with a shining parch- ment-like skin, and may be kept for any time. When using it, it is jilaced for a few minutes on the water-bath until sufficiently liquid lor application. (It should be quite fluid.) Should it at any time require too high a heat to become fluid, this may be corrected by adding a little water. It is applied by means of a broad brush, and forms in about two minutes a shining, smooth, flexi- ble, and nearly transparent skin. It may be kept for any time, without spoiling, in delf or earthen dishes or pots turned upside down.
Butter, R.\ncid, To purify. — Melt in twice its weight of boil- ing water and shake well. Pour the melted butter into ice- water, to regain its consistence. Another : Wash in good new milk, in which the butyric acid, which causes the rancidity, is freely soluble. Wash afterward in cold spring-water. Another plan is to beat up i lb. good fresh lime in a pail of water. Allow it to stand for an liour, until the impurities have settled. Then pour off the clear portion, and wash the butter in that.
Caps, P.vpek. To make. — Provide a sheet of moderately thick brown paper, size from 18 inches to 2 feet, shape as in Fig. 1. Smooth it out perfectly fiat, and double over as in Fig. 2. Turn it round with the fold from you, and mark the exact middle of tlie j)i('C<' at A, Fig. 3. Then bring down both corners, and measure off mi the edge B from the point .\, Fig. 3, a distance equal to ^ the circumference of your head. Mark the point. Now turn tin- paper over so that tin- under side will be upper- most, and bend the apex of the triangle back from the point just marked, as in Fig. 4. Fold over tin; sides. Figs. 5 and (!, and with scissors cut f)ff the portion, C, below the dotted lint*, and also tlie points of th(! two lower corners of the pieces just bent over. Next unfold the ])aper ; sprt'ad it out fiat : you will find a square marked in the middle, and creases leading there- from to the corners of the paper. Double up the material on these cri-ases, so as tf) bring up the paper as sides of a box, of which the iiiidille ^^l|uare is the bottom, as in Fig. 7. Smooth the folds fiat, and your work will ap|)ear as in Fig. H. Lastly, turn
HOUSEHOLD HINTS.
227
Fiq2
Fiq.S
Ficr.5.
MAKING PAPER CAPS.
up the edges of the box all around twice, folding the paper on itself. Your cap is then complete, and if the measurement di- rected above was correctly made, it will exactly fit your head.
Calico, To wash, without fading. — Infuse 3 gills of salt in 4 quarts of water. Put in the calico while the solution is hot, and leave until the latter is cold. It is said that in this way the colors are rendered permanent, and will not fade by subsequent washing.
Carpets, To prevent moth in. — Wash the floor before laying with spirits of turpentine or benzine. Do not do this with a fire in the room, or with any matches or lights near.
Casks.— Rancid butter, pork, and lard casks may be purified by burning straw or shavings in them.
,228 HOUSEHOLD HINTS.
Cellars, Dry-rot in. — This, in cellar timbers, can be pre- vented by coating the wood with whitewash to which has been added enough copperas to give the mixture a pale-yellow hue.
Cellars, Testing, for dampness. — Provide yourself with a thermometer, a glass tumbler filled with water, and a piece of ice ; then notice how low your thermometer, when placed in the tumbler, has to sink before any moisture begins to show itself on the outside of the vessel of cold water. The lower the tempera- ture to which the thermometer has to sink before moisture is precipitated, the less there is of it in the moisture of the cellar.
Chair-Bottoms, To restore elasticity of cane. — Turn the chair-bottom upward, and with hot water and a sponge wash the cane ; work well, so that it is well soaked ; should it be dirty, use soap ; let it dry in the air, and it will be as tight and firm as new, provided none of the canes are broken.
Chapped Haxds. — Rub over with fine soap, and, while the lather is still on, scrub the hands thoroughly with about a table- spoonful of Indian meal. Rinse with tepid water, dry thorough- ly, and wet again with warm water containing a quarter of a tea- spoonful of pure glycerine. Dry without wiping, rubbing the hands together until all the water has evaporated. Do this at night before retiring, and the effect will be apparent by morn- ing.
Chest-Protector, A simple. — A folded newspaper placed over the chest inside the vest, on going out during raw spring weather, constitutes an excellent protector for the lungs.
Chicken Feathers, Utilizing. — Cut the plume portions of the feathers from the stem, by means of ordinary hand-scissors. The former are placed in quantities in a coarse bag, which, when full, is closed and subjected to a thorough kneading with tlie hands. At the end of five minutes, the feathers become disaggregated and felted together, forming a down perfectly homogeneous and of great lightness. It is even lighter than natural eider-down, because the latter contains the ribs of the feathers, which give extra weight. About l.G troy ounces of this down can be ob- tained from the feathers of an ordinarj'-sized pullet. It is sug- gested that, throiigii the winter, children might collect all the featlicrs about a farm, and cut the ribs out as we have stated. By tlie spring-time, a large (]uantity of down would be j)repared, wliich could be disposed of to upholsterers, or enii)]oyed for do- mestic uses. Ooose-feathers may be treated in a similar manner, and thus two thirds of tlie product of the bird utilized, instead of r)nly aboutone fifth, as is at present thecase. Tiie chicken-down is.^aid to form a beautiful cloth when woven. F<ir about a scjuare yard of tin; material, a pound and a half of down is recjuired. 'I'iie fabric is said to be almost indestructible, as, in place of fray- ing or wearing out at folds, it only seems to felt the tighter. It takes dy(! readily, and is thoroughly water-i)roof.
Chkorv, Determination of, in ground coffee. — Gently strew tlie powderupon the surfaceof cold water. Chicory, burntsugar, etc., contain no oil, and their caramel is very (juickly extracted by the water, witli jiroduction of a brown color, while the parti-
HOUSEHOLD HINTS. 229
cles Hiemselves rapidly sink to tlie bottom of the water. On stirring the liquid, coffee becomes tolerably uniformly diffused without sensibly coloring the water, while chicory and other sweet roots quickly give a dark-brown turbid infusion. Roasted cereals do not give so distinct a color.
Chimneys, Burning, Prevention of. — The soot in the chimney can not burn', except as the fire of the stove is communicated to it through the pipe. If the pipe, therefore, be kept clean and free from soot, and the damper in the stove always closed, the chim- ney will never burn out. To free the pipe of soot, take the stove-handle or any convenient implement, and rap the pipe smartly on all sides from top to bottom. The soot will fall into the stove and be harmlessly consumed, or it can be removed in the usual way.
If there be a horizontal pipe, this should be taken down twice a year and thoroughly cleaned. Or, if the pipe be only a few feet in length, and the arrangements will admit of it, provide the horizontal pipe with a permanent scraper, as follows : To the end of a stout wire, a few inches longer than the pipe, attach a small segment of a disk of sheet-iron, at right angles to the wire. Eemove the elbow, and thrust the scraper into the pipe. Pass the other end of the wire through a hole punched in the elbow, loop the end of the wire for a handle, and replace the elbow. After first rapping the pipe, the soot can all be drawn out and letfall into the stove. Clean the pipe thus as often as once a fortnight during cold weather.
Chimneys, Smoky stove or range. — To prevent smoking, use a screen or blower of fine wire gauze, from 36 to 40 vdres to the inch, immediately in front of the fire and about two inches there- from.
Chimneys, Sooty, Cure for. — Plaster the inside with salt mortar. The proportions used are 1 peck salt added, while tem- pering, to 3 pecks mortar. Chimneys thus treated have re- mained perfectly clean for fifteen years.
Clothes, Fire-proof wash for. — Four parts borax and 3 parts Epsom salts, mixed with 3 or 4 parts warm water to 1 part of the combined substances, is an excellent fire-proof wash for clothes. It should be used immediately after preparation.
China and Glass Ware, Care of. — One of the most impor- tant things is to season glass and china to sudden change of tem- perature, so that they will remain sound after exposure to sudden heat and cold. This is best done by placing the articles in cold water, which must gradually be brought to the boiling point, and then allowed to cool very slowly, taking several hours to do it. The commoner tlie materials, the more care in this respect is required. All china that has any gilding upon it may on no account be rubbed with a cloth of any kind, but merely rinsed first in hot and afterward in cold water, and then left to drain till dry. It may be rubbed with a soft wash-leather and a little dry whiting ; but this operation must not be repeated more than once a year, otherwise the gold will most certainly be rubbed off, and the china spoilt. When the plates, etc., are put away in the china closet, pieces of paper should be placed between them
230 HOUSEHOLD HINTS.
to prevent scratches on the glaze or painting, as the bottom of all ware has little particles of sand adhering to it, picked up from the oven wherein it was glazed. The china closet should be in a dry situation, as a damp closet will soon tarnish the gild- ing of the best crockery. In a common dinner-service, it is a great evil to make the plates too hot, as it invariably cracks the glaze on the surface, if not the plate itself. The fact is, when the glaze is injured, every time the "things" are washed the water gets to the interior, swells the porous clay, and makes tlie Avhole fabric rotten. In this condition they will also absorb grease ; and when exposed to further heat, the grease makes the dishes brown and discolored. If an old, ill-used dish be made very hot indeed, a teaspoonful of fat will be seen to exude from the minute fissures upon its surface. These latter remarks apply more particularly to common wares.
As a rule, warm water and a soft cloth are all that is required to keep glass in good condition ; but water-bottles and wine-de- canters, in order to keep them bright, must be rinsed out with a little muriatic acid, which is the best substance for removing the "fur" which collects in them. This acid is far better than ashes, sand, or shot ; for the ashes and sand scratch the glass, and if any shot is left in by accident the lead is poisonous.
Richly-cut glass must be cleaned and polished with a soft brush, upon which a very little fine chalk or whiting is put ; by this means the lustre and brilliancy are preserved.
Cider-Stains. — These may be removed by lemon-juice or citric acid.
Cinders, Sifting. — To insure servants doing this, and to pre- vent vegetable refuse being thrown into the ash-barrel, provide a grated cover for the latter, which secure by a padlock to pre- vent removal.
Cisterns, Cleaning. — This should be done just before warm weather sets in, and should be done every year.
Clinkei{S, To remove, from stoves or fire-brick. — Put in about half a peck of oyster-shells on top of a bright fire. This may need rei)eating.
Clothing, Winter. — Sufficient clothing should be worn to keep off a feeling of chilliness when about usual avocations. Less than that subjects one to an attack of dangerous pneumonia at any day or liour. More than tliat oppresses. Steadily aim, by all possibh; ways and means, to keep oiT a feeling of chilli- ness, wliidi always indicates that a cold has bt^en taken.
Clothes, Protective power of. — Clothes pn^tect tlie body, by allowing through their interstices such ventilation tliat the nervous system nuiy not be senHil)le to extremes in changes of temperature. Dr. Petteukofer states that e(|ual sui-faces of vari- ous materials are jxTuu'ated hy air as follows, (Ininiel Ix^iiig taken as 100 : Linen of medium fineness, 58 ; silk, 10 ; buckskin, 58 ; tanned loatlier, 1 ; chanujis leather, 51.
Clo'I'IIKs, |{eMovating old. — Two ozs. coiuiihmi tnitacco boiled in 1 gallon water is UHc;d l)y the Chatham-street dealers for reno- vating old clothes. Tlie stuil is rubbed on with a stiff brush.
HOUSEHOLD HIKTS. 231
The goods are nicely cleaned, and, strange to add, no tobacco smell remains.
Clothes, Washing compound for. — The German washerwo- men use a mixture of 2 ozs. turpentine and 1 oz. spirits of ammonia well mixed together. This is put into a bucket of warm water, in whicli i lb. soap has been dissolved. The clothes are immersed for 24 hours and then washed. The cleans- ing is said to be greatly quickened, and 2 or 3 rinsings in cold water remove the tui'pentine smell.
Cockroaches, To drive away. — Poke-root {p/iytolacca de- candra), sliced thin and laid about a house, will destroy cock- roaches quicker than any other poison. It never lails. Another way of preparing the root is to boil 1 oz. in 1 pint water, until all the strength is extracted. Mix with molasses, and spread on plates in the localities infested by the insects.
Cork, To remove a, when pushed in a bottle. — When a cork gets pushed down into the neck of a bottle, insert a loop of strong twine and engage the cork in any direction most convenient. Then give a strong pull, and the cork will generally yield suffi- ciently to be withdrawn.
Corn, To can green. — Dissolve 2\ ozs. tartaric acid in a pint of water. Of this solution, use 1 tablespoonful to every pint of corn while the corn is at boiling heat. When opened for use, add 1 teaspoonful soda to every 3 pints of corn.
Cushions, Stuffing. — Flaxseed and tallow are used in Germany as a stuffing for cushions. One part of tallow to 10 parts of flax- seed are employed, the mobility of the greased seed rendering the cushion very soft and pliable.
Disinfectant for the Breath, etc. — A very weak solution of permanganate of pntasli is an excellent disinfectant for light pur- poses, such as rinsing spittoons, neutralizing the taint of diseased roots of teeth, cleansing the feet, and keeping the breath from the odor of tobacco-smoke. Permanganate is not poisonous.
Engravings, To clean mildewed or stained. — Moisten the paper carefully, and suspend it in a large vessel partially filled with ozone. To evolve the latter, the simplest way is to clean pieces of phosphorus and place them, half covered with water, in the bottom of the jar in which the pictures are hung. On a large scale, a Ruhmkorff coil, giving a constant discharge of electricity, would be preferable.
Eye, To remove substances from the. — Take hold of the upper eyelid, near its angles, with the index-finger and thumb of each hand. Draw it gently forward, and as low down as possible over the lower eyelid, and retain it in this position for about a minute, taking care to prevent the tears from flowing out. When, at the end of this time, you allow the eyelid to resume its place, a flood of tears washes out the foreign body, which will be found adhering to, or near, the lower eyelid.
Fermentation of Food. —This should be guarded against as the warm weather approaches. This action is always liable to cooked vegetables when set aside. Instead of warming up cold messes, it is better to scald them.
232 HOUSEHOLD HINTS.
Bugs, Fleas, etc. , To destroy. — This mixture, wliicli lias been patented in France, consists of 80 parts of bisulphide of carbon and 30 parts of essence of petroleum.
Floors, Cheap paint for. — This is made of 5 lbs. French ochre, ^ lb. glue, and 1 gallon hot water. AVhen well dried, apply one or two coats of linseed-oil.
Floors, Oak stain for. — An oaken color can be given to new pine floors and tables by washing them in a solution of copperas dissolved in strong lye, a pound of the former to a gallon of the latter. When dry, this should be oiled, and it will look well for a year or two ; then renew the oiling.
Floor Wax, Preparation of. — Heat to boiling 2 ozs. of pearl- ash, 10 ozs. of wax, and i pint of water. Stir frequently, until a thick fluid mass is formed from which, upon removal from the fire, no watery liquid separates out. Add boiling water cautiously, until no watery drops are distinguishable. Place on the fire again, but do not allow to boil, and add by degrees 8 or 9 pints of water, stirring constantly.
Earthenware, Porous, To clean. — This often becomes foul with organic matter when used to hold water. Use 1 oz. mu- riatic acid, rubbed on exterior and interior with a piece of flan- nel. Wash afterward with hot water.
Egos, To preserve. — Mix together in a tub or vessel 1 bushel of quicklime, 32 ozs. of salt, 8 ozs. cream of tartar, with as much water as will reduce the composition to a sufficient consistence to float an egg. It is said that this treatment will preserve the eggs perfectly sound for two years at least.
Flowkrs, Preserving. — The flowers must be carefully sur- rounded by perfectly dry, fine sand, in such a manner that they will h<»ld their form, the jtressure of tlie sand upon all surfaces being alike. Any fine clean sand will answer ; it should be sifted to remove all coar.se particles, and tlien washed in successive waters until du.st and all earthy and clayey matters are washed away, and the last waters when jioured off are perfectly clear. The sand is then to be dried and then placed ovt-r a fire in a proper vessel, until (juite hot, hotter than the hand can bear, and wlien cool it will l)e fit to use. After heating, it should be used at once, before it can absorb moisture from tlie air. Good results have been obtained by takinj; a clean, thoroughly dry flower-pot, the hole in the bottom r)f which was stopped by a cork. This was filled a third full of the dry sand, the flowers Het carefully in the sand, and then nior" sand slowly added, so as to surround and cover tiie flowers inside and out, and set in a warm place. At the end of 24 hours, the cork was removed from llie liolo in the flower-pot, and the sand allowed to run out in a small and gentle stream. The flower« were left in the pot, jKjrfectiy dry.
Flv-Pai'kr, Adiiksive. — Smear paper with a mixture of mo- lasBcs and linseed-oil.
Fk.\(imknts OK .Mktal, Extracting, from the flesh. — A simple and u.-sually succis.sful modi- of extracting a n<-edle, or any jjieco of steel or iron broken o(T in the flesh, ia accomplished by the
HOUSEHOLD HINTS. 233
application of a simple pocket inaguet. Iron filings have a way of imbedding themselves in the eye which defies almost every ordinary means for their extraction. For their removal, a small, blunt, pointed bar of steel, well magnetized, will be found excel- lent, and we should reconmiend that workmen liable to such iu- juries keep such an instrument about them. It would be a good ])!an to insert such a bar in a penknife, in a manner similar to a blade.
FnriT, Canning. — The following table for boiling fruit in cans will douijtless prove useful. The first figure after the name of the fruit refers to time of boiling in minutes, the second to ounces of su;iar to the quart : Cherries, 5, 6 ; raspberries, 6, 4 ; blackberries, 6, 6 ; gooseberries, 8, 8 ; currants, 6, 8 ; grapes, 10, 8 ; plums, 10, 8 ; peaches (whole), 15, 4; peaches (halves), 8, 4; pears (whole), 30, 8 ; crab-apples, 25, 8 ; quinces (sliced), 15, 10 ; tomatoes, 30, none ; beaus and peas, 3 to 4 hours.
Furnace Heat, To moisten. — Dry furnace heat, productive of throat and lung diseases, may be moistened by hanging a wet towel in front of the register," the lower edge of the towel being allowed to dip in a shallow vessel of water.
Fttrnace, To prevent rust in a. — Throw some quicklime loose- ly on a board, and place inside the furnace.
Furniture, Refinishing oiled or varnished. — Oiled furniture, scratched or marred, may be restored by rubbing with a woolen rag dipped in boiled linseed-oil. Varnished, by similarly rubbing with a varnish of shellac dissolved in alcohol.
Fabrics, To make uninfiammable. — The lightest materials are rendered uninfiammable by washing in a concentrated neutral so- lution of tungstate of soda, diluted with about one third of water, and then mixed with 3 per cent of phosphate of soda.
Feet, Frosted.— These can be relieved of soreness by bathing in a weak solution of alum.
Ferns, Ornaments made of. — Handsome ornaments can be made by mounting fern-leaves on glass. The leaves must first be dyed or colored. They are then arranged on the mirror ac- cording to fancy. A buttcrfiy or two may be 'added. Then a sheet of clear glass of the same size is placed on top, and the two sheets secur d together at the edges and placed in a frame.
Fire-Alarm, A simple and good. — An old gun loaded with a heavy charge of powder, and hung near the ratters in a barn, or in any dangerous locality about tlie house, makes an excellent fire-alarm. The explosion is caused by the heat.
Fire, Extinguishing. — A solution of pearlashin water, thrown upon a fire, extinguishes it instantly ; the proportion is 4 ozs., dissolved in hot water, and then poured into a bucket of common water.
Fires, Kerosene. — Never try to extinguish a kerosene fire with water. Smother the flames with blankets or rugs.
Fire, Precautions in case of. — Keep all doors and windows of the structure closed until the firemen come ; put a wet cloth over the mouth and get down on all fours in a smoky room ; open the
234 HOUSEHOLD HINTS.
upper part of tlie window to get the smoke out. If in a theatre, keep cool. Descend ladders with a regular step, to prevent vibra- tion. If kerosene just purchased can be made to burn in a sau- cer by iirniting witli a match, throw it away. Put wirework over gaslights in show-windows ; sprhikle sand instead of sawdust on floors of oil stores ; keep shavings and kindling-wood away from steam-boilers, and greasy rags from lofts, cupboards, boxes, etc. ; see that all stove-pipes enter well in the chimney, and that all lights and fires are out before retiring or leaving place of busi- ness ; keep matches in metal or earthen vessels, and out of the reach of children ; and provide a piece of stout rope, long enough to reach the ground, in every chamber. Neither admit any one, if the house be on fire, except police, firemen, or known neigh- bors ; nor swing lighted gas-brackets against the wall ; nor leave small children in a room where there are matches or an open fire; nor deposit ashes in a wooden box or on the floor ; nor use a light in examining the gas-meter. Never leave clothes near the fire- place to dry ; nor smoke or read in bed by candle or lamp light ; nor put kindling-wood to dry on top of the stove ; nor take a light into a closet ; nor pour out liijuor near an open light ; nor keep burning or other inflammable fluids in a room where there is a fire ; nor allow smoking about barns or warehouses.
Fires, Usual causes of. — Churches and lecture-rooms of all descriptions. — Hot air, hot water and steam i>ipes, and furnaces and stoves. Sticking candles against coffins in vaults. Christ- mas and other decorations around or too near gas-fittings, fires, or lights. Sparks falling upon birds' nests in spires andbellries. Curriers and workers in leather. — Lime slaked by rain. Sparks from foul fines and furnaces jjassing through opening and ] ro- jecting eaves of drying-rooms. Friction of niacliinery in bark- mills. Timb(n-, coals, shavings of wood, and leather too nearfiue.^. Drying stoves and furnaces. Spontaneous ignition. Smoking in bark and other rooms.
Drapers, tailors, makers up and vendors of male and female iit- tire. — \N'orking late, being tired and falling aslecj), or becoming careless too way iires and lights. Unprotected and swinging gas- brackets. Crinolines coming in contact witli fire in op:,'n fire- places. Light, ])endent goods being l)lown, by tlie o])ening and shutting of d(K)rs or Ijy concussions or drafts, into unprotected liglits. (ioods hung on lines increase the risk in various ways, Hucli as conveying the fiame from one end of a room to tlie other, and, wiien tin; line lireaks down, making three sej)arate fires, one ut eacli end and one in the middle at the same time, thus originating three distinct fires for CHch line. Cuttings left carelessly a])out. Using lights while intoxicated, esp(;cially by tailors' work-])eo])l(!. Ironing-stoves, liot jilates, smoothing-irons, etc., loo near and sometimes on timber and goods. Smoking-to- bacco, and niatdn-s for lighting it.
Engineering irarks, and irorkern in metal if all descriptions. — Sparks from striking liot metal, liot metal castings, etc., left too near timber. Heat from furnaces, forges, and smitlis' hearths and flues. Friction of nnichinery. .lapunners' stoves overln^ated or dt;- fective. Accidents with inelti'd or hot metal. lOxjjIosions of lilast furnaces. Sifontaneous ignition of oily waste, moulders' lamp, and
HOUSEHOLD HINTS. . 235
Other blacks ; sawdust or sweepings and oil ; spontaneous heating of iron turnings, etc., when mixed with water and oil.
Farming -stock, stables, My, yrain, or flour stores of^ all descnp- tions. — Stacking hay while green. Sparks from passing locomo- tives, etc. Sparks "from steam thrashing machines. Sticking candles against walls and timber in barns and stables. Vagrants smoking in stables. Vagrants being refused alms. Fire-arms used near farming-stock, such as haystacks, etc.
Makers of gunpowder, firetcorks, lucifer matches, and explosive compounds. — Overheating of drying-stoves and explosive mix- tures. Dropping lucifers. Unprotected lights. Smoking. Leav- ing phosphorus uncovered with water. Friction and percussion from nails in boots. Sparks passing through broken windows. The sun's rays being concentrated through bull's-eyes, knots, etc., in glass.' Defective casks containing gunpowder or other explosive materials. Spontaneous ignition of red fire and such- like compositions. Carelessness in the supervision of young children employed. Shavings and chips too near fires and lights.
Gas-works. — Hot coke near timber, etc. Seeking for an escape with unprotected lights. Timber too near furnaces, retorts, etc. Lime slaked by raiu. Defective fittings and appliances. Spon- taneous ignition of coals.
Hat manufactories. — Boiling shellac. Hot irons left on timber and other inflammable things. Defective drying and other stoves. Smoking tobacco.
Fishing, Comfortable. — A plan practiced on the Western lakes in winter consists in having a small house, built on run- ners like those of a sled, in which is placed a small stove, while in the floor a small aperture is left through which to drop the lines. Holes are cut in the ice, the houses are moved over them, and the fishermen sit by a warm stove while drawing in the fish.
Fish, Gold, Treatment of. — Seth Green says this as to the proper care and treatment of gold-fish : " Never take the fish in your hand. If the aquarium needs cleaning, make a net of mosquito-netting and take the fish out in it. There are many gold-fish killed by handling. Keep your aquarium clean, so that the water looks as clear as crystal. Watch the fish a little, and you will find out when they are all right. Feed them all they will eat and any thing they will eat — worms, meat, fish- wafer, or fish-spawn. Take great care that you take all that they do not eat out of the aquarium ; any decayed meat or vegetable in water has the same smell to fish that it has to you in air. If your gold-fish die, it is attributable, as a rule, to one of three causes — handling, starvation, or bad water."
Fishing-Lines, To water- proof. —Apply a mixture of 2 parts boiled linseed-oil and 1 part gold size ; expose to the air, and dry.
Flannels, To wash. — Take soft water, as warm as you can bear your hands in. Make a strong suds, well blued. In wash- ing fine flannels, wet but one piece at a time ; soap the dirty spots and rub witli the hands, as washboards full the flannels. When half clean, add three times as much blue as for cotton clothes. Use plenty of soap. When clean, have ready a rinse of
236 HOUSEHOLD HINTS.
the same temperature as the suds, rinse well, wruig tight, shake briskly for a few minutes, hang out in a gentle breeze. When nearly dry, roll smooth and tight for an hour or two. Press with a moderately hot iron. If embroidered, press on the wrong side. Flaimels washed in this way will look white and clean when worn out, and the quality will look better than when new.
Garbage, To dispose of. — When not fed to pigs, the best way to get rid of kitchen refuse is to burn it in the range or stove.
Gas Escaping, To detect. — To find the leak, first see that no burners have been left accidentally turned on. This is often the case where the cock has no stop, and is caused by the cock being partially turned around again so as to open the vent. Imperfect stop-cocks for this reason are dangerous, and should be promptly repaired. Try all the joints of the gas-fittings, by bringing a lighted match near them, to ignite the escaping gas if any there be. In case it is found by the sense of smell that the gas is escaping either within the floor or walls, do not on any account apply a match near a crevice. Turn off the gas at the metre, and send for a gas-fitter at once. In ordinary leaks, the burner or joint should be unscrewed, and white lead or common bar- soap rubbed in the threads before screwing home again.
(jrAS-LiGHT, Average prices of, in the United States. — Maine, $3.87. New- Hampshire, $3.9(). Vermont, $-1.80. Massachusetts, $3.86. Rhode-Island, $3.35. Connecticut, $-4.03. New- York, $3.88. New Jersey, $3.80. Pennsylvania, $3.46. Delaware, $3.95. Mary- land, $3.59. Dist. of Columbia, $3.16. Virginia, $3.89. West- Virginia, $3.11. North-Carolina, $6.67. So'uth-Carolina, $3.80. Georgia, $5.07. Fl(n-ida, $S.O0. Alaliama, $4.83. Mississippi, $5.25. Michigan, $3.43. W^isconsin, $3.87. Ohio, $3.33. Indiana, $8.54. Illinois, $3.87. Kentucky, $3.92. Tennessee, $4.06. Min- nesota. $4.31. Iowa, $4.52. Missouri, $3.95. Arkansas, $5.00. Louisiana, $4.50. Texas, $5.75. Kansas, $4.55. Colorado, $5.00. Utah, $4.00. California, $6.11.
Total average net price of gas in the United States, $4.32*.
Gilt Frames, To restore. — Rub with a sponge moistened in turpentine.
Gl.\ss, To break in any required form. — Make a small notch, by means of a file, on the edge of a piece of glass ; then make the end (if a tiihacco ])i])(', or a rod of iron about the same size, red-hot in the fire, a])])ly the hot iron to the notch, and draw it slowly along the surface of the glass in any direction you please ; a rrack will Ix; made in the glass and will follow the di- rection of the iron. Round glass bottles and flasks may be cut in tiic middle by wrap])ing round them a worsted thread dipped in spirits of turpentine, and setting it on lirt' wlien fastened on the glass.
(iLAHS Jars, To cut. — Fill the jar with lard-oil to where you want to cut the jar ; then heat, an iron rod or l)ar to red heat, im- merse it in the oil ; the unefpiiil exi)ansion will rlieck the jar all round at the surface! of the oil, and you can liftoff the top part.
(ii.Ass, To cut without a diamond. — Hold it level under water, and, with a pair of scissors, dip it away by small bits from the edges.
HOUSEHOLD HINTS. 23*7
Grease-Spots on Clothing, To remove. — In using benzole or turpentine, people make the mistake of wetting the cloth with the turpentine and then rubbing it with a sponge or piece of cloth. The only way to radically remove grease-spots is to place soit blotting-paper beneath and on top of the grease-spot, which spot has first been thoroughly saturated with the benzole, and then well pressed. The fat gets now dissolved and absorbed by the paper, and entirely removed from the clothing.
Hams, Pickle for curing. — An excellent, well-recommended pickle for curing hams is made of 1^ lbs. of salt, i lb. of sugar, I oz. of saltpetre, and i oz. of potash. Boil all together till the dirt from the sugar has risen to the top and is skimmed. Pour it over the meat, and leave the latter in the solution for 4 or 5 weeks.
Heaeths, Soapstone, To wash. — Use pure water, and then rub with powdered marble or soapstone put on with a piece of the same stone.
Hearths, To clean gray marble. — Kub with linseed-oil, and no spots will show.
Ice-Water, To preserve. — Make a hat-shaped cover of two thicknesses of paper, with cotton batting ^ inch thick between. Place over the entire pitcher
Incubator, A cheap. — One of the easiest constructed forms of incubator for the artificial hatching of eggs consists simply of a cask well buried in a manure-heap. In the bottom of the cask place one or two sieves to hold the eggs, and make a door in the side for the removal of chickens, etc. A pane of glass may also be inserted either in the do<ir or at any convenient point for view- ing the interior. In the head, which should be removable, make an opening provided with a sliding cover, for regulating the size of the aperture, as may be necessary. Form a bed of fresh manure about 1 ft. thick (after bedding) and 6 ft. scjuare. On this set the cask, and pack more manure around the latter until flush with the top. Now take off the head or cover and place a thermometer on one of the sieves. Replace the cover. The natural heat of the manure will warm the interior of the cask. When the temperature reaches 104' (seen by the thermometer), place the eggs on the sieves. The hatching process then begins, and lasts the usual time. Care should be taken to turn the eggs over once a day, and to allow them to cool slightly, thus imitat- ing the natural habit of the hen when she leaves her nest in search of food. The temperature of the interior is kept uniform at 104° by removing manure from the side of the cask to lessen the heat, or by substituting manure fresh from the stables in place of the older material, in order to increase the warmth.
After the chickens have emerged from the shell, the inte- rior of the cask should be carefully cleaned, and an artificial " mother" placed inside. This last "consists of a loosely-fitting disk of wood, covered on its under side with sheepskin or a piece of buf?alo-robe. Under it the chickens nestle. It may be sup- ported from the head by a piece of cord, or by a rod held in clamps, so that its distance from the bottom of the cask may be
238 HOUSEHOLD HINTS,
adjusted to suit. The warmtli necessary for the young chickens is maintained by the manure, so that the hitter answers both for this purpose and foi- the hatching. The slide mentioned above, as located in the head of the cask, is intended for ventilating the interior.
This plan is now in practical operation on one of the largest poultry farms in the country and i.s evidently more simple than any other involving the use of s])ecial a])i)aratus and gas or lamps for heating. A cylindrical vessel must be used— never a square one, since the chickens, in the latter case, will crowd into corners and smother each other. The number of (yggs hatched depends upon the size of the cask or the number of casks used. As many as one thousand eggs have been thus incubated at a time. Any farmer having a manure-heap, however small, can easily test the plan, if only with a dozen eggs. The matter requiring the greatest care is to keep the temperature in the cask uniform, and to have the manure sheltered from rain, which would cool it.
Ink, Indelible, To remove. — If the ink is a nitrate of silver preparation, it may be taken out of the fabric (1) by washing the latter in a solution of hyposulphite of soda, or (2) by moistening it with a solution of bichloride of cojiper, and then washing it with liquid ammonia.
Ink-Stains, To remove, from mahogany. — Put a few drops of spirits of nitre in ateaspoonful of water, touch the spot with a fea- ther dipped in the mixture, and, on the ink disappearing, rub it over inmiediately with a rag wetted in cold water, or there will be a white mark which will not easily be effaced.
Ink-Stains, To remove. — Wasli carefully with pure water, and apply oxalic acid ; and, if the latter changes the dye to.a red tinge, restore the color by ammonia.
Insect Bites. — A good remedy is borax, 1 oz., dissolved in 1 pint water previously boiled and allowed to cool.
Keys, Fitting. — Wln-n it is not convenient to take a lock apart to fit a new key, the key-blank shouUl be smoked over a can(lU\ inserted in the keyhole, and ])ressed firmly against tiie opposing wards of the lock. The indentations in the smoked portion made by the wards will show where! to file.
Lamp-Burnehs, To fasten kerosene. — Plasttsr of Paris mixed with resin soap is a good cement for this purpose.
Lkad-Comc, Preventives of. — If working in lead, wash the liands several times a day in a strong decoction of oak-bark. Keep the liair short, and (if a ])ainler) wear a clean cloth cap. Tlie clothes should be freciuently washed, and tiie liands also, es- jx-cially before touching food. Befon^ eating, the moutli sliould be rinsed with cold water. A weak oak i)ark di'coctioii sliouhl be usi'd as a wasli si'vcral tinn-saweek. 'I'iie l)ndy sliould be sponged niglit and morning with cold or te]>id water, and the liair tho- rouglily wasiied evtTy (!V(uiing afttsr work. Tlie food should con- tain a large proportion of fatty substances, and milk should be taken in largt? (]uaiitilies.
liEAK AM) Flowkk Imi'KEHSIONS, To make. — Take a small quantity of printer'n ink, thinly put it on glass, evenly distribut-
HOUSEHOLD HINTS. 239
ed. The end nf the index-finger will serve as the printer's ball, to cover one side of the leaf uniformly ; then lay it to the exact place where you wish the print to be ; lay over it a piece of thin, soft paper large enough to cover it ; then, without moving the leaf, press all parts of it with the end of the thumb firmly, and you will have a perfect impression, that no engraver can excel ; and by adjusting the leaves at the proper points, accurate prints can be taken, and, aided with the brush or pen, the stem and whole plant can be shown. Excellent specimens of impressions of barks of trees can be made by slicing the bark ; and with a little care, the stems can also be taken, as well as flowers. When colored with the aniline colors, they are very like colored en- gravings.
Leather, To water-proof. — Saturate with castor-oil. This is excellent for winter boots.
Life Preserver, A simple.— It is not generally known that, when a person falls into the water, a common felt hat can be made use of as a life-preserver. By placing the hat upon the water, rim down, with the arm around it pressing it slightly to the breast, it will bear a man up for hours.
Linen, To bleach. — Javelle water, used for turning white the dirtiest linen and removing stains, is composed of bicarbonate of soda, 4 lbs. ; chloride of lime, 1 lb. Put the soda into a kettle over the fire, add 1 gallon of boiling water, let it boil from ten to fif- teen minutes, then stir in the chloride of lime, avoiding lumps. Use when cool. This is good for removing fruit-stains from white underwear.
Marble, To clean. — Common soda, 2 parts ; pumice-stone (pul- verized), 1; finely powdered chalk, 1. Sift through a fine sieve, and mix with water. Rub all over the marble until the stains are removed. Then wash the stone with soap and water. Marble that is yellow wnth age, or covered with green fungoid patches, may be rendered white by first washing it with a solution of per- manganate of potash of moderate strength, and while yet moist with this solution, rubbing with a cloth saturated with oxalic acid. As soon as the portion of the stone operated upon becomes white, it should be thoroughly washed with pure water to re- move all traces of the acid.
Match-Scratchers. — The best are pieces of shark-skin, or squares of fine wire gauze.
Mice, To kill. — Sprinkle some grain near the holes, and throw near by a few bits of cotton saturated in chloroform. This has been tested, and mice have been found dead, two or three at a time, lying with their noses near the cotton.
Mildew, To remove. — Make a very weak solution of chloride of lime in water (about a heaping teaspoonful to a quart of water), strain it carefully, and dip the spot on the garment into it ; and if the mildew does not disappear immediately, lay it in the sun for a few minutes, or dip it again into the lime-water. The work is effectually and speedily done, and the chloride of lime neither rots the cloth nor removes delicate colors, when
240 HOUSEHOLD HIJfTS.
sufficiently diluted aud the articles rinsed afterward in clear water.
Moss Ornaments. — A beautiful orr anient for tlie sittinjr-room can be made by covering a common glass tumbler with moss, tlie latter fastened in place by sewing-cotton wound around. 'I'hen glue dried moss upon a saucer, into which set the tumbler, filling it and the remaining space in the saucer with loose earth from the woods. Plant tlie former with a variety of ferns, and the latter with wood-violets. On the edge of the grass also plant some of the nameless little evergreen vine, which bears red (scarlet) berries, and whose dark, glossy, ivy-like foliage will trail over the fresh blue and white oi the violets with beautiful effect. Another good plan is to fill a rather deep plate with some ot the nameless but beautiful silvery and light green and delicate pink mosses, which are met with in profusion in all the swamps and marshes. This can be kept fresh and beautiful as long as it is not neglected to water it profusely once a day. It must, of course, be placed in the shade, or the moss will blanch and die. In the centre of this, a cliinip of large azure violets should be placed, adding some curious lichens and pretty fungous growth from the barks of forest-trees, and a few cones, shells, and pebbles.
Mosquitoes, To drive off. — Rub the skin with essence of penny- royal, or with a little coal-oil on a bit of cotton. The smell of the oil disappears in a few minutes.
Mustard Poultice:, To make a. — In making a mustard plaster use no water, but mix the mustard with white of egg, and the result will be a plaster whicli will draw perfectly, but will not produce a blister, no matter how long it is allowed to remain.
Mucilage, Pocket. — Boil 1 lb. best white glue, and strain very clear ; boil also 4 oz. isinglass, and mix the two together ; i)lace them in a water-bath (glue-kettle) with ^ lb. white sugar, and evaporate till the liquid is quite thick, when it is to be poured into moulds, dried, and cut into pieces of convenient size. This immediately dissolves in water, aud fastens paper very firmly.
Newspaper Binder, Temporary. — Take two pieces of light wire, strong enough to reach across the paper once, and throe or four ])ieces of stout thread. Place one wire under tlie i)ni)('r as far from the edge as yon choose to bind it. Put the threads around the lower wire up through the paper, and tie them over tlie other wire on toj). 'I'emporary covers of stiff ])asteb<)ard may be added, liaving lioles for the reception of the thread, the wires being placed on the outside of the cover. The successive papers are, of course, to be threaded, one by one, by means of an awl or coarse needle.
Oil-Cloths, Cleaning.— These should not bo washed with soap. A coat of good copal varnish at long intervals improves them. Oil-cloths sliould never bn scrubbed. Wipe with a wet cloth, after brusliing with a soft floor- brush.
Oir.ED Floors.— Tli(! scrajyings from these should immediately he placed in the open air. They are liable to sjiontaneous com- bustion.
HOUSEHOLD HINTS 241
Oil-Paintings, To restore old. — Take the painting out of tbe frame, lay it on a table, face up, and keep a wet cloth on it for two or three days, cliangiug or cleaning the cloth as often as it becomes soiled. When the painting is clean, wash it with a sponge or brush dipped in nut-oil. This is much better than varnishing
Painter's Colic. — (1.) One drachm of sulphuric acid in 10 pints of table or spruce beer, or mild ale. Shake well, and allow it to stand for a few hours. Take a tumlilerful twice or three times daily. (2.) Make a beer of molasses, 14 lbs. ; bruised gin- ger, ^ lb.; coriander-seed, i oz.; capsicum and cloves, i oz. each ; water, 12i galls.; yeast, 1 pint. Put the yeast in last, and let it ferment. When the fermentation has nearly ceased, add sul- phuric acid, li OZ3., mixed with 12 ozs. water, and 14 ozs. bicar- bonate of soda dissolved in water. It will be fit to drink in three or four days.
Paint, To clean. — Dip a flannel rag into warm water, and wring it out nearly dry. Take up on the rag as much whiting as will adhere, and' rub this on the paint until the dirt or grease disap- pears. Wash the part well with clean water, and rub dry with soft chamois-skin.
Paint, To remove, from clothes. — Chloroform will remove paint from a garment or elsewhere, when benzole or bisulphide of carbon fails.
Paint, To remove old. — Slake 3 lbs. of stone quicklime in water, and add 1 lb. American pearlash, making the whole into the consistence of paint. Lay over the old work with a brush, and let it remain for from 12 to 14 hours, when the paint is easily scraped off.
Paper Comforters. — Two thicknesses of paper are better than a pair of blankets, and much lighter for those who dislike heavy bedclothes. A spread madt- of double layers of paper tacked to- gether, between a covering of chintz or calico, is really a de- sirable household article. Soft paper is the best, but newspapers will answer.
Papering Walls. — Papering and painting are best done in cold weather, especially the latter, for the wood absorbs the oil of paii*t much more than in warm weather ; while in cold weather the oil hardens on the outside, making a coat which will protect the wood instead of soaking into it. Never paper a wall over old paper and paste. Always scrape down thoroughly. Old paper can be pot off by damping with saleratus and water. Then go over all the cracks of the wall with plaster of Paris, and, finally, put on a wash of a weak solution of carbolic acid. The best paste is made out of rye-flour, with 2 ozs. glue dissolved in 1 qt. paste ; \ oz. powdered borax improves the mixture.
Paste, A superior flour. — Thoroughly mix good clean flour with cold water to a paste, then add boiling water, stirring up well until it is of a consistence capable of being easily spread with a brush. Add to this a little brown sugar, a little corrosive sublimate, and about half a dozen drops of oil of lavender; and keep, if convenient, two days before using.
242
HOUSEHOLD HTXTS.
Petkoleum Bakkels. — These sliould not lie used to store food 3r drink in. They are poisonous even after being cleaned.
Plant-Case, A housetop or window. — A fernery or plant-case niiorht he arranged to run the whole length of the front windows of a story, and he heated by a small boiler placed behind a fire-
RECTIOX OF ri..\.NT-CAJiE.
place. From this a 2-inch flow and return ))ipe is taken tlirougli the case, so as to heat it when rctpiired. The space around the ])\\>ci^ can he lillcd with hark, or water if desirable, .so as to ])roducf a moist and genial bottom lieat. The ferns, mosses, and other decorative plants, are arranged in flat s(]uaro pans of zinc or earthenware, as shown in our sectional sketch, and the efTect of the whole, especially when sei-ii from within, is very effective, and afTonls relief to tlie eye, which might otherwise looii out f)n a dismal prospect of blackened roofs and Hoof-begrinuHl cbininey-pots.
Pl,ANT8, Window, Cnre of. — Plants kept in the windows should lie turned every ni'iniing, or the light, striking on one side only, will draw the ])lant to thiif side, so that all its branches and leaves will turn toward the wimlow. The water in the saucers should never In- ap))lie(l to the plants. Fn cutting slips
HOUSEHOLD HINTS. 243
of any plant, always choose the youngest branches ; and cut ofi the sli)) at the junction of a joint or leaf, since the roots shoot more readily from such joints. If you follow these directions, and put sufficient sulphate of ammonia to just taint the water applied to your plants, you may cultivate with success almost any plant, even though you are an entire novice.
Plant-Cases, Wardian, Management of. — The following prin- ciples are those upon which a fern-case should be constructed : 1. Have no apparatus or arrangement for drainage. 2. Make your case as air-tight as possible, allowing for no ventilation.
Ferns require, tor their growth, shade and moisture : upon the former, in a great degree, depends the latter. A northern or eastern aspect, where the morning sun reaches the case, we tliink is best. As regards moisture, we have the principle of self-sup- port in an air-tight case ; for if you allow the sun to reach the case for an hour or so in the morning, you will find that the moisture needful for the growth of your ferns is extracted from the earth ; and when evening comes, this same moisture will condense and fall. Each day, this process of extraction and con- densation takes place, and your plants flourish under a necessary and sufficient moisture. Now, this being the kind of air we want, we must not, of course, ventilate our case, and allow it to escape, otherwise the dry air of our rooms would enter, and the watering of the case become a necessity. This at once upsets all the benefits derived from these cases. The temperature, also, must be much more even in an air-tight case than in a ventilated one, where the constant opening and shutting of doors and win- dows would affect it. If we have no watering to do, we have no water to run off", and consequently require no drainage in the hot tom of our case. Now, in this air-tight principle, we get at the secret.
In stocking Wardian cases, the amateur will find that almost all ferns and mosses will do well in this case. There ^re few of our greenhouse ferns that will not do well under this treatment ; the gold and silver ferns are perhaps the exception ; they do not always attain their full size and beauty in a Wardian case, but the adiantums, pteris, polypodiums, blechnums, and others do well.
In planting a case, do not place the plants too near, nor use too many of a large size, but put in a few plants and of a mode- rate size. Water well after setting the plants out. and shade the case for a day or two ; then give it the morning sun each day for an hour or two, and your ferns will soon start. Nothing can be more interesting than to watch them — the frond pushes its head above the earth, the heat and moisture of the case have their effect, and it gradually rises and uncurls till it reaches its height, then it expands into the most beautiful and giaceful of shapes ; then what can exceed in delicacy and freshness this newly-born part ? The lycopodiums grow finely, and spread very rapidly in the case ; small pieces introduced at regular intervals in the case will, in a marvelously short time, double their original size ; and if the pendent roots of the creeping species are pressed well on to the surface of the earth, the spaces between the plants and ferns will soon be filled up, and a rich and delicate carpet be produced
244
HOUSEHOLD HIXTS.
over the whole case. For climbers, nothing can give more satis- faction th.a.njicusstiptdata, which can be obtained at all green- houses. The roots of this plant, which strike out at every joint.
THE PltlNCESS OF WALES CASE.
have an adhesive power, and will attach themselves firmly to the glass in the case, which renders the growth more rapid and regu- lar. It is a very interesting plant to wutch ; the roots adhering to the glass allow a free use of the nucroscope, and the growtli and circulation can be studied to great advantage from the out- side of the case.
TlIK ^VDKMIA.M I A^K.
Ah to soil, tlie brst mixture for tin- growth of ferns and lycopodiuinH is the fnllDwiiig: lit-af mould, 2 parts; fresh sanil, 1 ])urt ; gnivcl, about the sizr of a ]»t'a. 1 jiart ; and stal)lc nuinure, clioppcd v«Ty fine, 1 part. Ferns whir-ji grow na- turally in dry plares c-an be arranged on rock-work in the centre
HOUSEHOLD HINTS. 245
of the case, if it is large enough to admit of it, and those re- quiring more moisture should be placed nearer the sides of the case, and they will get more moisture from the glass, where it deposits in grer.t quantities. Tlie spores of ferns can be sown on the surface of the earth in the Wardian case, and a constant sup- ply of young plants can in this way be obtained, thus enabling the student to watch them in every stage of development.
It happens that not un frequently the larvae of insects are in- troduced in the earth into the case, and hatch out under the in- fluence of the heat. To provide agahist this, it will be found useful and interesting to put in a small-sized toad, and insects will disappear very soon, and give no further trouble. Toads will live through the winter perfectly well in this way, and their habits can be studied ; some may become aware, by trying this experiment, that the toad, although not one of the handsomest of our reptiles, is not the least interesting.
Plants, Potting. — Those who find their efEorts to raise house- plants frustrated by worms may be able to win success by boiling the earth before setting the plants. Use little water, and allow it to simmer away after a few minutes of hard boil.
Polish, Furniture. — Shave very fine white wax, 3 ozs., cas- tile-soap, 1 oz. ; put the was in 1 gill turpentine, and let it stand 24 hours. Boil the soap in 1 gill water, and add to wax and tur- pentine.
Potatoes, Saratoga, Fried. — The following is all there is of the cook's secret for producing those w'orld-renowned potatoes served at Moon's Lake House, Saratoga Spr ngs, every summer : Peel good-sized potatoes, and slice them as evenly as possible ; drop them into ice-water. Have a kettle of lard, as for fried cakes, and veTj hot. Put a few at a time into a towel, shake them about to dry them, and then drop into the hot lard. Stir them occasionally ; and when of a light brown, take them out with a skimmer. If properly done, they will not be at all greasy, but crisp without, and mealy within.
Potatoes, Frozen. — These can be cured by soaking in water 3 days before cooking.
Rust-Spots, To remove from cloth. — Wet the spots of iron- rust on muslin or white dress-goods thoroughly with lemon-juice, then lay in the hot sun to dry. Repeat the same if the color is not removed by one application. When dry, rinse in clear, cold water. Lemon-juice can notbe used on colored goods, as it will take out printed colors as well as stains. It will rernove all kinds <'f stains from white goods.
Ring, To remove, when tight on the finger. — In case a finger- ring becomes too tight to pass the joint of the finger, the finger should first be held in cold water to reduce any swelling or infiam- mation. Then wrap a rag soaked in hot water around the ring to expand the metal, and lastly soap the finger. A needle threaded with strong silk can then be passed between the ring and finger, and a person holding the two ends and pulling the silk, while sliding it around the periphery of the ring, will readily remove the latter. Another method is to pass a piece of sewing-silk un-
246 HOUSEHOLD HINTS.
der the ring, and wind the thread iu pretty close spirals aud close- ly around the finger to the end — that below the ring — and begin unwinding.
Rice, To boil. — The way they boil rice in India is as follows : Into a saucei)au of 3 quarts water, when boiling, throw a table- spoonful of salt ; then put in 1 pint rice, previously well washed in cold water. Let it boil 20 minutes, throw out in a colander, drain, and put back in tlie saucepan, which should be stood near the fire for several minutes.
Rain- Water, To preserve sweet. — A drachm of pounded alum to a gallon of water is sufficient. After 24 hours, the water will be cleansed. All wooden vessels to hold water should be cliarred inside. If a mixture in the proportion of ^ lb. of lime, made into a paste, and added to a spoonful of powdered alum, be put into 200 gallons of water, it will soften the water, and precipitate vegeta- ble and other matter.
-- Rats, Bait for. — Put a drop of rhodium oil on a bit of cheese or meat. These animals detest chloride of lime and coal-tar.
, Rats, To catch. — Cover a common barrel with stifl' paper, tying the edge around the barrel. Place a board so that the rats can have easy access to the top. Sprinkle cheese or other bait on the paper, and allow the rats to eat there unmolested for several days. Then place in the bottom of the barrel a stone G or 7 inches high, and pour in water until all the stone is covered, except for a space about big enough for one rat to crawl upon. Now replace the paper, first cutting a cross in the middle. The first rat that ilimbs on the barrel-top goes through into the water, and climbs on the stone. The paper comes back to its original posi- tion, ami the second rat follows the first. Then begins a fight for the possession of the dry place on the stone, the noise of whicli attracts the others, who share the same fate.
Razors, Paper for sharpening. — By merely wiping the mzor on the paper to remove the lather after shaving, a keen edge is main- tained without further trouble. The razor must be well sharpen- ed at the outset. First, procure oxide of iron (by the addition of carbonate of soda to a solution of persulphate of iron), well wash the j)recii)itate, and finally leave it of the consistence of cream. Spread this over soft paper very thinly with a soft brush. Cut the pa{)er in pieces two inches square, dry, and it is ready for use.
RAZOK-STROr, To maki- a. — Select a piece of satin, maple, or ro.se wimkI, 12 inches long, IJ inches wide, and findi thick ; allow 'Si inches for length of handle. Half an inch from where the liandle begins, notch out the thickness of tin; leather so as to make it flush toward the end. Taper also the thickness of the leather; this precaulirjn i)revents the case from tearing up tlie leather in putting the strop in. Tlicm round the wckmI very slightly, just enough (say I'j of an inch) to keep from cutting by the ruznr in stniijping and turiiiug over tin- same. Now select a priiptT sizi-d |)ie(C()f fine French bookbinder's tiilfrtkiii, cover with good whfut or ry<- paste, then lay the edge in tin- notch, and se- cur.' it in place with a small vise, proceed to rul) it down firmly
HOUSEHOLD HINTS. 247
and as solid as possible witli a tootli-brush handle (always at liand, or should be), and, after the whole is thoroughly dry, trim it neat- ly and make the case.
Sleeplessness, Cure for.— Mr. Frank Buckland says : " If I am much pressed with work, and feel I shall not sleep, I eat two or three small onions, and the effect is magical. Onions are also excellent things to eat when much exposed to intense cold. In salmon-fishing, common raw onions enable men to bear the ice and cold of the semi-frozen water much better than spirits, beer, etc. If a person can not sleep, it is because the blood is in his brain, not in his stomach ; the remedy, therefore, is obvious : call the blood down from the brain to the stomach. This is to be done bv eating a biscuit, a hard-boiled egg, a bit of bread and cheese," or something. Follow this up with a glass of wine or milk, or even water, and you will fall asleep."
Smoked Meat, To preserve. — The keeping qualities of smoked meat do not depend upon the amount of smoking, but upon the uniform and proper drying of the meat. It is of considerable ad- vantage also to roll the meat on its removal from the salt, before smoki'ng, in sawdust or bran. By this means the crust formed in smoking will not be so thick ; and if moisture condenses upon the meat it remains in the bran, the brown coloring matter of the smoke not penetrating. The best place to keep the meat is in a smoke-house, in which it remains dry without drying out entirely, as it does when hung in a chimney.
Spatter- Work Pictures. — These are delicate designs in white appearing upon a softly-shaded ground. Procure a sheet of fine uncalendered drawing-paper, and arrange thereon a bouquet of pressed leaves, trailing vines, letters, or any design which it is de- sired to have appear in white. Fasten the articles by pins stuck into the smooth surface, which should be underneath the paper. Then slightly wet the bristles of a tooth or other brush in rubbed Indian ink, or in common black writing-ink. and draw them across a stick in such a manner that the bristles will be bent and then quickly released. This will cause a fine spatter of ink upon the paper. Continue the spattering over all the leaves, pins, and paper, allowing the centre of the pattern to receive the most ink, the edges shading off. When done, remove the design, and the forms will be found reproduced with accuracy on the tinted ground. With a rustic wooden frame, this forms a very cheap and pretty ornament.
Spoons, To remove stains on, caused by boiled eggs. — Rub with common salt.
Sponges, Cleaning. — A gelatinous substance frequently forms in sponges after prolonged use in water. A weak solution of permanganate of potassa will remove it. The browm stain caused by the chemical can begot rid of by soaking in very dilute muria- tic acid. An old and dirty sponge may be cleaned by first soak- ing it for some hours in a solution of permanganate of potassa, then squeezing it, and putting it into a weak solution of hydro- chloric acid, 1 part acid to 10 parts water.
248 HOUSEHOLD HINTS.
Sponges, To bleach. — \Va;<li first in weak muriatic acid, then in cold water ; noak in weak sul[iluuic acid, wash in water again, and finally rinse in rose-water.
^ Stains of Acid Fuuit, To remove, from the hands. — Wash the hands in clear water, wipe them lightly, and while they are yet moist, strike a match and shut your hands around it so as to catch the smoke, and the stain will disappear.
Starch, To prevent souring when boiled. — Add a little sul- phate of copper.
Stone, To remove moss from. — This is useful for the green mould which forms on marble and brown stone steps. Apply a solution of 75 grains ot carbolic acid to 1 quart of water.
Stoppers, Glass, To remove. — To move a tight glass stopper, hold the neck of the bottle to a fiame, or take two turns of a string and seesaw it. The heat engendered expands the neck of the bottle before the expansion reaches the stopper.
Stove-IIolks in Walls. — See that these openings for the pipes are protected by good tin covers alter the stoves are taken down. Do not stuff rags in.
Straw MATTiN(i, Washing, — Use a cloth dampened in salt, water. Indian meal sprinkled over it and thoroughly swept out will also cleanse it finely.
Styptic Paper, for stopping the bleeding of small wounds. — Mix gum benzoin (best quality), 1 lb.; rock alum, 1 lb.; water, 4^ gals. Boil in a tin vessel for 4 hours, replacing the water lost by evaporation. Saturate paper with the solution, dry carefully, and brush over with a concentrated solution of perchloride of iron. Keep in a water-proof and air-tight case.
Safk, Home-made fire-proof. — The best is a hole in the ground well lined with brick and cement.
V SniHT-BosOMS, Glossing, — Take 2 ozs. of fine white gum-ara- bic powder, put it in a jjitcher, and pour on a pint or more of wa- ter, and then, having covered it, let it stand all night. In the morning, pour it carefully from tln^ dregs intn a clean bottle, cork, and keep it for use. A teaspoonful of gum-water stirred in a l)int of starcli.made in the usual way, will giver to lawns, white or printed, a lf>nk of newness when notliing else can risstore them, after they have hft-n washed.
Shoes, Bronzing. — Black shoes may be bronzed by a strong solution of aniline red in alcohol.
SifoKs, Black varnish for. — Take 10 parts, by weight, of shellac, and ") of turpentine. Dissolve in 40 jiarts alcohol, in which fluid should be previously dissolved 1 part extract of logwood, with some- neutral diromate of potassa and snlphati^ of indigo. This varnish is to be kipt in well-stopjiered bottles.
SiDKWALKS, Slii)i)ery. — Put on hot sand instead of ash(!B.
Silk, Washing. —Tlie way to wash silk is to spn^ad it Hinootlr ly upon a cleiin lioaid, ml) whili^ soap ujjon it, ami brush it wit'i a clean hand brush.
SiLVKIt, To chsan. — A strong solution of hyposulphite of soda is uhhIuI for this puriM)H(;.
HOUSEHOLD HINTS. 249
Silk, etc., To clean. — A teaspoouful of powdered borax dis- solved in 1 qt. tepid water is good for cleaning old black dresses of silk, cashmere, or alpaca.
Silver-Plate, To keep bright.— Warm the articles, and coat carefully over with thin collodion diluted with alcohol, using a wide soft brush for the purpose.
Sink-Spouts, To thaw frozen. — Place one end of a piece of lead pipe against the ice to be thawed, and then through a funnel in the upper end pour boiling water. Keep the pipe constantly against the ice, and a foot or more per minute can be penetrated. In order to thaw out water-pipes that become frozen and are inac- cessible, the plan used by New-York plumbers is to surround small india-rubber tubing with coiled wire so as to stiffen it and admit of its being inserted far into the pipe. Tlu-ough the tube a current of steam from a small boiler over a charcoal furnace is allowed to pass. This acts very quickly, except when the pipe takes a very irregular course, in which case there is no remedy ex- cept to dig down into the earth or break out walls until the pipe can be reached, and thawed by the direct application of heat.
Soap, Adulteration of, by starch.— This is detected by dissolv- ing the soap in alcohol, which leaves the starch behind.
Soap, Gall, To make. — Gall soap, excellent for washing silks and ribbons, may be made by heating 1 lb. cocoanut-oil to 60° Fahr. , into which | lb. caustic soda is gradually stirred. To this I lb. Venice turpentine, previously warmed in another vessel, is added. The kettle is allowed to stand for four hours, subject to a gentle heat, after which the fire is increased until the contents are perfectly clear. One pound ox-gall, followed by 2 lbs. castile- soap, is then mixed in, and the whole allowed to cool, when it may be cut into cakes.
Soap, Habd, To prevent crumbling. — Dip the bars in a mixture of resin-soap, beef-tallow, and wax.
Soap, Home-made. — Soap-making is not an easy process ; some- times the ashes are poor, or the right proportions of lye and grease are not used ; at other times the soap appears to be good when put up, but changes entirely after standing a few days. The last trouble usually arises from getting the soap too strong and diluting with water. If very strong, it will be thin and dark ; and by adding cold water and thoroughly stirring, the color is changed many shades lighter and the mass thickened, giving it the appearance of a No. 1 article, while in reality it is very poor. Hickory-ashes are the best for soap-making, but those from sound beach, maple, or almost any kind of hard wood except oak, will answer Avell. A common barrel, set upon an inclined platform, makes a very good leach ; but one made of boards set in a trough in V-shape is better, for the strength of the ashes is better obtained, and it may be taken to pieces when not in use, and put away. First, in the bottom of the leach, put a few sticks ; over them spread a piece of carpet or woolen cloth, which is much better than straw ; put on a few inches of ashes, and then from 4 to 8 qts. lime ; fill with moistened ashes, and pack well down. Pack the finest in the centre. It is difficult to obtain the full strength of ashes in a barrel without removing them after a day's
250 HOUSEHOLD HINTS.
leaching, and mixing tliem up and reitlacinii,-. Tlie top should be first thrown (jff and new ashes added to make up the proper quan- tity. Use boiling water for second leaching. Take about 4 gal- lons lye, and boil up thoroughly with 12 lbs. clear grease, then add the lye as it is obtained, keeping a slow tire and stirring often until you have a barrel of soap. After boiling the grease and 4 gallons lye together, it may be put in a barrel and the rest of the lye added there. This will form good soap if frequently stirred ; but the heating process is the best, when weather and time will permit.
Tattoo-Marks on the Skin, To remove. — Blister the part with a plaster a little larger than the mark ; then keep the place open for a week with an ointment ; finally, dress it to get well. As the new skin grows, the tattoo-marks will disappear.
Tau-Spots, To remove. — Butter will remove tar-spots. Soap and water will afterwaid take out the grease-stain.
Tea-Kettle, To prevent rust forming inside a. — Keep an oyster- ' shell in the bottom of the kettle ; and when water is wanted, pour off without agitating the vessel. Be careful also not to let the water stand in the vessel when not in use.
Teeth, Extracting, Simple method of, for children. — The ope- ration consists in simply slipping a rubber ring over the tooth and forcing it gently under the edge of the gum. The patient is then dismissed, and told not to remove the a])pendage, which in a few days loosens the tooth, and causes it to fall out.
V Tin. Scouring. — Kerosene and powdered lime, whiting, or wood- ashes, w-ill scour tins with the least labor.
vToothache — Saturate a bit of cotton wool in a strong solution of ammonia, and apply it immediately to the affected tooth. \^ Tubs and Pails, to prevent shrinking of. — Saturate with gly- cerine.
Vegetables, To wash. — Vegetables should never be washed until immediately before prepared for the table. Lettuce is made alnir)st wortlilcss in liavor by (li])i)iiig it in water some hours be- fore it is served, i'otatoes suff'cr even more than other vegetal)les througli the washing [iroceas. They shoukl not be j)ut in water till just ready for boiling.
Vkntilation ok Sleei'INO-Rooms, Simple ))lan for. — A ])iece of wood ;{ ill. liigh, and exactly as long as the breadth of the window, is to be ])r(!i)ared. Let the sasli l)e now raised, the slip of wood placetl on the sill, and tlus sash drawn chjsely upon it. If the slip has l)een w(!ll fitted, tliere will be no draft in conse- <|iient'e of tliis displacement of the sash at its lower i)arl. ; but the top of tlie lower sash will overlap the liottoni of tlie ii])per one, and l)etw(;en tlie two bars prr]>en(liciil!ir currents of air, not felt as draft, will enter and leave the room.
ViNEfiAH, 'i'o make, from molasHes. — Vinegar may be made by mixing Ki ](arts pun^ water, 1 part syrup <>f molasses, and 1 part baker's yeast at a temperature of al)out HO Kalir. , and k<^epingtlie <-otnpoun<l in a warm atniosi)here from ten to thirty days. A little old vinegar, udijed im tlie sei-oml or third il;iy, will aid the proceHH,
I
HOUSEHOLD HINTS. 251
Vinegar, Raspberry. — Pour over 1 lb. bruised berries, 1 qt. of the best cider vinegar ; nextdsiy, strain the liquor on 1 lb. of fresh ripe raspberries, bruise them also, and on the following day do the same. Do not squeeze the fruit, only drain the liquor thoroughly. Put the juice into a stone jar, and add sugar in pro- portion of 1 lb. to a pint. When the sugar is melted, place the jars in a saucepan of water, which heat ; skim the liqui>r, and after it has simmered for a few minutes, remove from the fire, cover, and bottle.
Washing-Elite. — Twenty lbs. white potato starch, 20 lbs. wheat starch, 20 lbs. Prussian blue, 2 lbs. indigo carmine, and 2 lbs. finely-ground gum-arabic are mixed in a trough, with the gradual addition of sufficient water to form a half-fluid, homogeneous mass, which is then poured out on a board with strips tacked to the edges. It is then allowed to dry in a heated room until it does not run together again when cut. It is next cat, by a suitable cutter, into little cubes, and allowed to dry perfectly. They are finished by lieing placed in a revolving drum, with a suitable quantity of dry and finely pulverized Paris blue, until they have a handsome appearance. The cost is about 12 cents per pound.
V Washing Colored Fabrics. — Before washing almost any colored fabrics, soak them in water, to each gallon of which a spoonful of ox-gall has been added. A teacupful of lye in a pail of water is said to improve the color of black goods. A strong tea of common hay will improve the color of French linens. Vinegar in the rinsing water, for pink and green, will brighten those colors ; and soda answers the same end for both purple and blue.
Wall-Paper, Removing stains on.'— Stains on wall-paper can be cut out with a sharp penknife, and a piece of paper so nicely inserted that no one can see tlie mtch.
Warts, Cure for. — Rubbing warts, night and morning, with a moistened piece of nauriate of ammonia is said to cause their disappearance without pain or a scar resulting.
H Water-Closets, Ventilating pipes for. — Extend pipes from water-closet traps, or one (larger) from the main waste-pipe, into the nearest chimneys. The pestilent gases will thus be carried off instead of being allowed to escape into the house. ^ Water, Hard, To soften. — Boil or add a small quantity of quicklime mixed to a cream with water.
Water, To purify, from smoke. — Enough permanganate of pota?sa is added to give the faintest possible tinge to the water. After standing 24 hours, the impurities will all be precipitated. ^^ Wounds, Cut. — A wound made by a knife or other sharp in- strument is best healed by bringing the edges together and put- ting on a bandage which "will not exclude the air. Nature will work the cure, if the person be healthy, much better than anv salve or ointment.
Water-Lilies, To raise.— Water-lilies may be raised about one's house by the following method : Sink in the ground the half of an old cask, and cover the bottom with peat and swamp
252 HOUSEHOLP HINTS.
mud, and then fill witli water. Dig the lily roots early in the spring, and place them in the earth at the bottom of the tub.
> Windows, Washing. — In washing windows, a narrow-bladed wooden knite, sharply pointed, will take out the dust that hardens in the corners of the sash. Dry whiting will polish the glass, which should first be washed with weak black tea mixed with a little alcohol. Save the tea-leaves for the purpose.
Wine, Preservation of, by heating. — Wine maj' be kept with- out altering in quality for an indefinite period of time, in all climates, after ha%'ing been first submitted to the action of artifi- cial heat. The temperature to which it must be raised is from 131' to 140" Fahr. If the wine does not contain naturally more than 10 or 12 per cent of alcohol, it is best to add li per cent more before the shipping of it. The wine is to be heated by steam and artificially cooled.
Yeast, Compressed. — Previously malted barley and rye are ground up and mixed, next put into water at a temperature of G5° to 75' ; after a few hours the saccharine liquid is decanted from the dregs, and the clear liquid brought into a state of fer- mentation by tlie aid of some yeast. The fermentation becomes very strong ; and by the force of the carbonic acid which is evolved, the yeast globules are carried to the surface of the liquid, and, forming a thick scum, are removed by a skimmer, then placed on cloth filters, drained, washed with a little distilled water, and next pressed into any desired shape by means of hydraulic pressure, and covered with a strong and well-woven canvas. It keeps from 8 to 14 days, according to the season, and is excellent.
Yeast for Hot Climates. — Boil 2 ozs. best hops in 4 qte. water for A hour ; strain and cool to new-milk warmth. Put in ^ lb. sugar, 1 tablf 'Spoonful of salt ; beat up 1 lb. of the best flour with some of tht! liquor, and mix all well together. Let it stand for 3 days, and on the third day add 3 lbs. mashed and boiled jjota- toes. On the next day, strain, and it is ready for use. This will keep for 2 or 3 months in a moderately cool place. The yeast is very strong ; half the usuiU quantity necessary for baking is sufficient.
Yeast, Vienna. — Vienna bread and Vienna beer are said to be the best in the world. Hoth owe their superiority to the yeast used, which is ])rep»ro(l in the following nuinner : Indian corn, barley, and rye (all sprouting) are powdered and mixed, and then macfrated in water at a temperature of from 149' to Iti? Fahr. Saccharification takes jilace in a few liours, when the liiiuor is racked off and allowed to clear, and fermentation is set uj) by the help of a minute quantity of any ordinary yeast. Carbonic acid is disengaged during the process with so much rapidity that the globules of yeast are thrown up by the gas, and remain floating on the surface, where tiiey form a thick scum. Tlie latter is carefully removed, and constitutes the best and purest yeast, which, when drained and compressed in a liydraiilic press, can be kei)t from H to 1.1 days, according to the season.
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