It is also the only obstacle which the adult will encounter at the moment of exit. To lessen the difficulty of opening it, the grub takes the precaution of gnawing at the inner side of the skin, all round the circ.u.mference, so as to make a line of least resistance. The perfect insect will only have to heave with its shoulder and strike a few blows with its head in order to raise the circular door and knock it off like the lid of a box. The pa.s.sage of exit shows through the diaphanous skin of the pea as a large circular spot, which is darkened by the obscurity of the interior. What pa.s.ses behind it is invisible, hidden as, it is behind a sort of ground-gla.s.s window.
A pretty invention, this little closed porthole, this barricade against the invader, this trap-door raised by a push when the time has come for the hermit to enter the world. Shall we credit it to the Bruchus? Did the ingenious insect conceive the undertaking? Did it think out a plan and work out a scheme of its own devising? This would be no small triumph for the brain of a weevil. Before coming to a conclusion, let us try an experiment.
I deprive certain occupied peas of their skin, and I dry them with abnormal rapidity, placing them in gla.s.s test-tubes. The grubs prosper as well as in the intact peas. At the proper time the preparations for emergence are made.
If the grub acts on its own inspiration, if it ceases to prolong its boring directly it recognizes that the outer coating, auscultated from time to time, is sufficiently thin, what will it do under the conditions of the present test? Feeling itself at the requisite distance from the surface, it will stop boring; it will respect the outer layer of the bare pea, and will thus obtain the indispensable protecting screen.
Nothing of the kind occurs. In every case the pa.s.sage is completely excavated; the entrance gapes wide open, as large and as carefully executed as though the skin of the pea were in its place. Reasons of security have failed to modify the usual method of work. This open lodging has no defence against the enemy; but the grub exhibits no anxiety on this score.
Neither is it thinking of the outer enemy when it bores down to the skin when the pea is intact, and then stops short. It suddenly stops because the innutritious skin is not to its taste. We ourselves remove the parchment-like skins from a mess of pease-pudding, as from a culinary point of view they are so much waste matter. The larva of the Bruchus, like ourselves, dislikes the skin of the pea. It stops short at the h.o.r.n.y covering, simply because it is checked by an uneatable substance.
From this aversion a little miracle arises; but the insect has no sense of logic; it is pa.s.sively obedient to the superior logic of facts. It obeys its instinct, as unconscious of its act as is a crystal when it a.s.sembles, in exquisite order, its battalions of atoms.
Sooner or later during the month of August we see a shadowy circle form on each inhabited pea; but only one on each seed. These circles of shadow mark the doors of exit. Most of them open in September. The lid, as though cut out with a punch, detaches itself cleanly and falls to the ground, leaving the orifice free. The Bruchus emerges, freshly clad, in its final form.
The weather is delightful. Flowers are abundant, awakened by the summer showers; and the weevils visit them in the lovely autumn weather. Then, when the cold sets in, they take up their winter quarters in any suitable retreat. Others, still numerous, are less hasty in quitting the native seed. They remain within during the whole winter, sheltered behind the trap-door, which they take care not to touch. The door of the cell will not open on its hinges, or, to be exact, will not yield along the line of least resistance, until the warm days return. Then the late arrivals will leave their shelter and rejoin the more impatient, and both will be ready for work when the pea-vines are in flower.
To take a general view of the instincts in their inexhaustible variety is, for the observer, the great attraction of the entomological world, for nowhere do we gain a clearer sight of the wonderful way in which the processes of life are ordered. Thus regarded, entomology is not, I know, to the taste of everybody; the simple creature absorbed in the doings and habits of insects is held in low esteem. To the terrible utilitarian, a bushel of peas preserved from the weevil is of more importance than a volume of observations which bring no immediate profit.
Yet who has told you, O man of little faith, that what is useless to-day will not be useful to-morrow? If we learn the customs of insects or animals, we shall understand better how to protect our goods. Do not despise disinterested knowledge, or you may rue the day. It is by the acc.u.mulation of ideas, whether immediately applicable or otherwise, that humanity has done, and will continue to do, better to-day than yesterday, and better to-morrow than to-day. If we live on peas and beans, which we dispute with the weevil, we also live by knowledge, that mighty kneading-trough in which the bread of progress is mixed and leavened. Knowledge is well worth a few beans.
Among other things, knowledge tells us: "The seedsman need not go to the expense of waging war upon the weevil. When the peas arrive in the granary, the harm is already done; it is irreparable, but not transmissible. The untouched peas have nothing to fear from the neighborhood of those which have been attacked, however long the mixture is left. From the latter the weevils will issue when their time has come; they will fly away from the storehouse if escape is possible; if not, they will perish without in any way attacking the sound peas. No eggs, no new generation will ever be seen upon or within the dried peas in the storehouse; there the adult weevil can work no further mischief."
The Bruchus is not a sedentary inhabitant of granaries: it requires the open air, the sun, the liberty of the fields. Frugal in everything, it absolutely disdains the hard tissues of the vegetable; its tiny mouth is content with a few honeyed mouthfuls, enjoyed upon the flowers. The larvae, on the other hand, require the tender tissues of the green pea growing in the pod. For these reasons the granary knows no final multiplication on the part of the despoiler.
The origin of the evil is in the kitchen-garden. It is there that we ought to keep a watch on the misdeeds of the Bruchus, were it not for the fact that we are nearly always weaponless when it comes to fighting an insect. Indestructible by reason of its numbers, its small size, and its cunning, the little creature laughs at the anger of man. The gardener curses it, but the weevil is not disturbed; it imperturbably continues its trade of levying tribute. Happily we have a.s.sistants more patient and more clear-sighted than ourselves.
During the first week of August, when the mature Bruchus begins to emerge, I notice a little Chalcidian, the protector of our peas. In my rearing-cages it issues under my eyes in abundance from the peas infested by the grub of the weevil. The female has a reddish head and thorax; the abdomen is black, with a long augur-like oviscapt. The male, a little smaller, is black. Both s.e.xes have reddish claws and thread-like antennae.
In order to escape from the pea, the slayer of the weevil makes an opening in the centre of the circular trap-door which the grub of the weevil prepared in view of its future deliverance. The slain has prepared the way for the slayer. After this detail the rest may be divined.
When the preliminaries to the metamorphosis are completed, when the pa.s.sage of escape is bored and furnished with its lid of superficial membrane, the female Chalcidian arrives in a busy mood. She inspects the peas, still on the vine, and enclosed in their pods; she auscultates them with her antennae; she discovers, hidden under the general envelope, the weak points in the epidermic covering of the peas. Then, applying her oviscapt, she thrusts it through the side of the pod and perforates the circular trap-door. However far withdrawn into the centre of the pea, the Bruchus, whether larvae or nymph, is reached by the long oviduct. It receives an egg in its tender flesh, and the thing is done.
Without possibility of defence, since it is by now a somnolent grub or a helpless pupa, the embryo weevil is eaten until nothing but skin remains. What a pity that we cannot at will a.s.sist the multiplication of this eager exterminator! Alas! our a.s.sistants have got us in a vicious circle, for if we wished to obtain the help of any great number of Chalcidians we should be obliged in the first place to breed a multiplicity of Bruchidae.
FOOTNOTES:
[Footnote 3: From _Social Life in the Insect World_, translated by Bernard Miall, Chapter XVIII. The Century Company, New York, 1913.]
[Footnote 4: This cla.s.sification is now superseded; the Pea and Bee Weevils--_Bruchus pisi_ and _Bruchus lenti_--are cla.s.sed as Bruchidae, in the series of Phytophaga. Most of the other weevils are cla.s.sed as Curculionidae, series Rhyncophora.--(Trans.)]
THE EXPOSITION OF A MANUFACTURING PROCESS
MODERN PAPER-MAKING[5]
_J.W. Butler Paper Company_
Though the steady march of progress and invention has given to the modern paper-maker marvelous machines by which the output is increased a thousandfold over that of the old, slow methods, he still has many of the same difficulties to overcome that confronted his predecessor. While the use of wood pulp has greatly changed the conditions as regards the cheaper grades of this staple, the ragman is to-day almost as important to the manufacturer of the higher grades as he was one hundred years ago when the saving of rags was inculcated as a domestic virtue and a patriotic duty. Methods have changed, but the material remains the same.
In a complete modern mill making writing and other high-grade papers, the process begins with unsightly rags as the material from which to form the white sheets that are to receive upon their spotless polished surface the thoughts of philosophers and statesmen, the tender messages of affection, the counsels and admonitions of ministers, the decisions of grave and learned judges, and all the
Wisdom of things, mysterious, divine, that Ill.u.s.triously doth on paper shine,
as was duly set forth in rhyme by the _Boston News Letter_ in 1769.
"The bell cart will go through Boston about the end of next month," it announced, and appealed to the inhabitants of that modern seat of learning and philosophy to save their rags for the occasion, and thus encourage the industry.
The rags do not come to the mammoth factories of to-day in bell carts, but by the carload in huge bales gathered from all sections of this great Republic, as well as from lands beyond the eastern and western oceans. The square, compact, steam-compressed bundles are carried by elevators well up toward the top of the building, where they await the knife of the "opener." When they have been opened, the "feeder" throws the contents by armfuls into the "thrasher." The novice or layman, ignorant of the state in which rags come to the mill, will find their condition a most unpleasant surprise, especially disagreeable to his olfactory nerves. Yet the unsavory revelation comes with more force a little farther on, in the "a.s.sorting-room." The "thrasher" is a great cylindrical receptacle, revolving rapidly, which is supplied with long wooden beaters or arms pa.s.sing through a wooden cylinder and driven by power. When the rags have been tossed in, there ensues a great pounding and thrashing, and the dust is carried off in suction air-tubes, while the whipped rags are discharged and carried to the "sorting" and "shredding" room. Here the rags are a.s.sorted as to size, condition, and the presence of b.u.t.tons, hooks and eyes, or other material that must be removed. Then those that need further attention are pa.s.sed on to the "shredders," these as well as the "sorters" being women. The "shredders" stand along a narrow counter; in front of each one there is fastened a long scythe-blade with its back toward the operator and its point extending upward, the shank being firmly fixed to the table or operating board. Here b.u.t.tons, hard seams, and all similar intruders are disposed of, and the larger pieces of rags are cut into numerous small ones on the scythe-blades. The rags thus prepared are tossed by the women into receptacles in the tables. The work in this room is the most disagreeable and unwholesome in the entire process of manufacture, and this despite the fact that these rags, too, have been thrashed, and freed from an amount of dust and dirt beyond belief.
While one is watching the operations carried on here, it is impossible to repress the wish that rags might be bought otherwise than by the pound, for, unfortunately, filth, dust, and dirt weigh, and to wash rags only reduces the weight. While this is a true reflection of the condition in the average mill, it is pleasant to know, however, there are others of the higher cla.s.s that are decided exceptions as far as dust and dirt are concerned. Such are the mills making high-grade ledger and bond papers, as well as the mill manufacturing the paper that is used for the printing of our "greenbacks," to which further reference will be made later. In these exceptional mills everything is neat and perfectly clean, all the stock used being new and fresh from the cotton or linen mills, or from factories producing cloth goods, like shirt and corset factories, and others of the same sort. The sorting and shredding room is always large and light, with windows on all sides, and well ventilated, offering a decided contrast in many respects to the less cleanly mills first referred to where the women must wear bonnets or hoods for the protection of the hair. In either case the process is certainly an improvement over the old plan of leaving the rags to decay in a cellar to expedite the removal of the glutinous matter from them.
From the "sorting" and "shredding" room the rags are conveyed to the "cutter," where they are cut and chopped by revolving knives, leaving them in small pieces and much freer from dust and grit. Various ingenious devices are employed for removing metal and other hard and injurious matter, magnetic brushes serving this purpose in some mills.
When the "cutter" has finished its work, the still very dirty rags go for a further cleansing to the "devil," or "whipper," a hollow cone with spikes projecting within, against which work the spikes of a drum, dashing the rags about at great speed. Human lives are often freed of their baser elements and restored to purity and beauty through the chastening influences of tribulation or adversity; in like manner the "whipper" carries the rags forward a step in the process of purification that is necessary before they can be brought to their highest usefulness. But the cleansing process, which is only a preparation for what is to follow, does not end with the "whipper," which has served merely to loosen, not to dislodge, a great deal of dust and dirt. The final operation in the preliminary cleaning is performed by the "duster"
proper, which is a conical revolving sieve. As the ma.s.s of rags is tossed and shaken about, the loosened dust is carried away by the suction of the air, which draws the dust particles into tubes furnished with suction fans. In most modern mills the rags are carried forward from the "duster" on an endless belt, and a careful watch is kept upon them as they emerge to detect the presence of unchopped pieces, b.u.t.tons, or other foreign substances. The journey of the rags over this endless belt or conveyor terminates in a receiving-room, in the floor of which there are several openings, and immediately below these the mouths of the "digesters," which are in a room beneath. The "digesters," as they are suggestively and appropriately termed, are huge revolving boilers, usually upright, which often have as great a diameter as eight feet, with a height of twenty-two feet and a digestive capacity of upward of five tons of rags each. The rags that are to be "cooked" are fed in to the "digesters" through the openings in the floor, and the great movable manhole plates are then put in place and closed, hermetically sealing the openings or mouths through which the boilers have been fed, these having first been charged with a mixed solution of lime and soda and with live hot steam in lieu of gastric juice as a digesting fluid and force. In some mills the boilers are placed in a horizontal position, while in others they are in the form of a large ball or globe, in either case being operated in the manner described; those of upright form, however, are most commonly in use. The rags are boiled under steam pressure of about forty pounds to the square inch, and the cooking is continued from twelve to fourteen hours.
It is here that the process of cleaning begins in earnest; and as the ma.s.s of rags is tumbled about in its scalding bath of steam-heated lime-water, or "milk of lime," the coloring and glutinous matters, as well as all other impurities, are loosened from the fibers, which are in the end so cleansed and purified as to come forth unstained and of virgin purity. Having been sufficiently boiled and digested, the mushy material, still looking dark and forbidding, is emptied onto the floor below or into receptacles placed directly beneath the boilers, where the color and dirt are allowed to drain off. The ma.s.s is then conveyed to the "washers," great tub-like receptacles, which are known as "Hollanders," from the fact that these rag engines were invented in Holland about the year 1750 A.D. They are oval-shaped tubs, about twenty feet long, nine feet wide, and three feet high, varying somewhat according to the conditions. Each tub is divided for two-thirds of its length by an upright part.i.tion, or "mid-feather," as it is called, which makes a narrow course around the vat. On one side of the part.i.tion, the tub is raised in a half-circle, close to which revolves an iron roll about three or four feet in diameter, and covered with knives; in the bottom of the tub, and directly under the revolving roll, is another set of knives called a "bed-plate," which is stationary, and against which the roll can be lowered. But let us not antic.i.p.ate. When the emptyings from the boiler have been thrown into the "washer," a continuous stream of water is turned in at one end, the knife-roll having been adjusted so as to open up the rags as they are set in motion. These then begin a lively chase around the edge of the vat, through the race-course formed by the "mid-feather," and under the rag-opening knives, where the water is given a chance to wash out all impurities, then on up the incline over the "back-fall," so-called from the elevation in the tub. A cylinder of wire-cloth, partly immersed in the moving ma.s.s, holds back the now rapidly whitening fibers, while the dirty water escapes into buckets inside the wire-cloth drum, and is discharged into and through an escape-spout. The heavy particles of dirt settle into what is termed a "sand-trap" at the bottom of the tub.
As the water clears, the roll is lowered closer and closer to the bottom of the bed-plate, in order to open up the fibers more thoroughly for the free circulation of the water among them. When the several agencies of the "washer" have accomplished their purpose and the water runs clear and unsullied, a bleaching material is put into the ma.s.s, which in the course of from two to six hours becomes as white as milk. The dirty offscourings of all ragdom, first seen in the original bales, and gathered from the four corners of the globe, have endured many buffetings, many bruisings and tribulations, and having been washed come forth pure, sweet, and clean. From the washers the rags are precipitated through a trap into drainers, which are chambers made of stone and brick, with a false bottom through which the water is allowed to drain.
This rag pulp, now called half stock, is kept in this receptacle until the water and liquor are thoroughly drained off, when it becomes a white and compact ma.s.s of fibers.
The rags should stand in the drainers for at least one week, though better results are obtained if they are left for a period two or three times as long, as the fibers become more subdued. The process of paper-making as it has already been described, applies more particularly to papers made from rags. To-day, a very large proportion of the cheaper papers are made from wood, either entirely or in part, and these wood-made papers are subjected to a different treatment, to which further reference will be made.
From the drainer the ma.s.s is carted to the beating engine, or "beater,"
which is very similar in construction to the washer just described. The knives on the roll in the beater are grouped three together instead of two, and are placed nearer the bottom or bed-plate in order to separate more thoroughly the fibers. In the beater are performed many and varying manipulations, designed not only to secure a more perfect product but also to produce different varieties of paper. It is the theory of the beating process that the fibers are not cut, but are drawn out to their utmost extent. In watching the operations of the "beater," one notices on the surface of the slowly revolving ma.s.s of fibers, floating bluing, such as the thrifty housewife uses to whiten fine fabrics. This familiar agency of the laundry is introduced into the solution of fibers with the same end in view that is sought in the washtub--to give the clear white color that is so desirable. Many of the inventions and discoveries by which the world has profited largely have been due primarily to some fortunate accident, and according to a pretty story upon which paper-makers have set the seal of their belief for more than one hundred and fifty years, the use of bluing was brought about in the same way.
About the year 1746, so runs the story, a Mrs. b.u.t.tonshaw, the wife of an English paper-maker, accidentally dropped into a tub of pulp the bag of bluing, or its contents, which she was about to use in a washing of fine linen. Frightened at what she had done and considering it the part of wisdom to keep silence, she discreetly held her peace and awaited results. But when her husband had expressed great wonder and admiration over the paper made from that particular pulp, and had sold it in London at an advance of several shillings over the price of his other paper, which had not met with any such accident, she realized that the time for silence had pa.s.sed. Her account of the happy accident led her grateful husband to purchase a costly scarlet cloak for her on his next visit to London town. This accident brought about another result which was to prove of inestimable value to the future paper-maker--the use of bluing in paper when especial whiteness is desired.
Important as the bluing or coloring is, however, it is only one of the numerous operations or manipulations that take place in the beater. Many of these, such as engine-sizing and body-coloring, require skill and constant watchfulness. Here, too, if anywhere, adulteration takes place.
It is sometimes necessary to secure a fine-appearing paper at small cost, and it is profitable to add to its weight. In such cases a process of "loading" takes place here, and clay or cheap, heavy fibers are added. Clay is of value not only to increase the weight but also to render the paper more opaque, so as to prevent type or ill.u.s.trations from showing through, while at the same time it makes possible a smoother surface by filling the pores in the paper. But while it adds to the weight, clay must, of necessity, weaken the paper. In engine-sizing, which is done in the beater, the size is thoroughly incorporated with the fibers as these revolve or flow around the engine. This sizing renders the paper more nearly impervious to moisture. The difference between a paper that is sized and that has a repellent surface which prevents the ink from settling into it when it is written upon, and an ordinary blotting-paper with its absorbent surface, is due entirely to the fact that the former is most carefully treated with sizing both in the beating engine and in the size tub or vat referred to later, whereas in the latter paper it is omitted. If the paper is to be tinted or body-colored, colors made from aniline are generally used. Only in the highest grade of writing-paper and in some few papers that demand colors fast to the light is any other order of coloring matter employed. As may be easily imagined, considerable skill is required to secure exactly the desired tint, and to get the coloring matter so evenly mixed that each small fiber shall receive its proper tint, and thus to insure that the paper when finished shall be of uniform color and not present a mottled appearance.
When the operations of the beating engine have been completed, a most interesting process begins which marks a vast advance over the earlier method of forming the sheets of paper with mould and deckel, straining off the water, and shaking the frame with a quick motion to mat the fibers together. The patient striving toward something better which has marked all the centuries since man first learned to carve his rude records, finds its consummation in the process of making paper in a continuous web. This result is accomplished by a machine first invented by Louis Robert, a workman in a mill at Enonnes, France, who obtained a French patent, with a bounty of eight thousand francs for its development. This he later sold to M. Didot, the proprietor of the mill, who crossed the Channel into England, where, with the aid of a skilled mechanic, the machine was in a measure perfected, and then sold to Henry and Sealy Fourdrinier. They, with the further aid of Bryan Donkin, their employee and expert engineer, made many additional improvements, and sank in the enterprise some sixty thousand pounds sterling, for which their only reward was blighted hopes and embittered lives. In 1847 the London _Times_ made a fruitless appeal on behalf of the surviving brother, who was eighty years of age and in great poverty. It is seldom that the world voluntarily makes return to those who have bestowed upon it great material or moral benefits, though it is ever ready to expend its treasure for engines of destruction and to magnify and reward those who have been most successful in destroying human life.
The first "machine" mill was started at Frogmore, Hertz, England, in 1803, which was the year of the great Louisiana Purchase by the United States, and it is not difficult to say which event has been productive of the greater and more beneficial results to this nation. Through this invention and its improvements, the modern newspaper and magazine, with their tens and hundreds of thousands of copies daily, have been made possible, and men of all cla.s.ses have been brought in touch with the best thought of the day. Whatever makes for greater intelligence and enlightenment throughout a nation makes for the greater stability of the national life, and gives new emphasis to Bulwer"s words:
Take away the sword; States can be saved without it--bring the pen.
If to-day the power of the pen over the sword is greater than it has ever been before, its increased and increasing influence must be credited in large measure to the inventive genius and the public-spirited enterprise that has made possible the great output of our modern paper-mills. So thoroughly did these forces do their work in the beginning that in the century that has elapsed since the Fourdrinier brothers sacrificed themselves and their means in the perfecting of their machine, there have been really no changes in the fundamental principle. Those that have been made have been in the nature of further development and improvement, such as increasing the speed and widening the web, thereby multiplying the product many fold.
But let us resume the interesting journey of the rags, which had reached a state of purification and perfection as pulp, and which we left in the beaters. In some grades of paper the perfected and prepared pulp is taken from the beaters and pa.s.sed through what is known as a "refining"
or "Jordan" engine for the purpose of more thoroughly separating the fibers and reducing them to extreme fineness. The refining engines are, however, used only in the manufacture of certain grades of paper. The pulp is next taken from the beater or refining engine, as the case may be, to what is called a "stuff-chest," an inclosed vat partly filled with water, in which a contrivance for shaking and shifting, properly called an "agitator," keeps the fibers in suspension.
From the stuff-chest the mixture is pumped into what is known as the "mixing" or "regulating" box. Here the stream first pa.s.ses over the "sand-tables" in a continuous flow. These are composed of little troughs with cross-pieces, and are covered at the bottom with long-haired felt, to catch any sand or dirt that may still adhere after the numerous operations to which the pulp has been subjected. The flow is then forced through the "screen," which is a horizontal piece of metal pierced with slots. For very fine paper these slots are so small as to be only one one-hundredth of an inch in width. They are usually about a quarter of an inch apart. Through these tiny apertures the fibers must find their way, leaving behind in their difficult pa.s.sage all lumps, dirt, or knotted fibers which would mar the perfection of the product toward which they are tending. A vibrating motion is given to the screen as the flow pa.s.ses over it, or revolving strainers may be used.
When the screen has finished its work, the water carrying the pulp in solution flows in an even stream, the volume of which varies according to the width of the web of paper to be produced, through a discharge-c.o.c.k onto the Fourdrinier or cylinder machine, as the case may be, each of which will be duly described. This stream has a filmy appearance and is of diverse color, depending upon the shade of paper to be produced. From its consistency, which is about that of milk, it is difficult to imagine that it floats separate particles of fiber in such quant.i.ties as, when gathered on the wire cloth and pa.s.sed to a felt blanket and then pressed between rollers, to form in a second of time a broad web of embryo paper sufficiently strong and firm to take definite form. Man"s mastery of the process by which this startling and wonderful change is effected has come as one of the rewards of his long and patient study.
The Fourdrinier machine, which preserves at least the name of the enterprising developers of the invention, takes up the work that was formerly done by the molder. The wire cloth upon which the fibers are discharged is an endless belt, the full width of the paper machine. Upon this the fibers spread out evenly, being aided by a fan-shaped rubber or oil cloth, which delivers the smooth stream under a gate regulated to insure perfect evenness and to fix uniformly the fibers of the web now commencing its final formation. Deckel-straps of india-rubber are fastened on both sides of the wire screen, and move with it, thus holding the watery pulp in place. The deckel-straps are adjustable and fix or regulate the width of the paper. These and the gate, or "slicer,"
are attached to what is termed the deckel-frame, which corresponds to the deckel used by paper-makers in the days when the manufacture was carried on by hand. As the stream flows onto the endless belt of wire cloth, the water which has borne the fibers filters into the trough beneath. Being charged with very fine fibers, size, coloring matter, and other similar ingredients, it is carried back into the pulp-chest to save these materials, as well as to contribute again to the extra supply of water needed. For this reason the trough into which it falls from the revolving "wire" is called the "save-all." A shaking motion is imparted to the "wire" from the frame upon which rest the rolls that keep it in its never-ending round. This aids in draining away the water and mats or interlaces the fibers together. At the end of the "save-all," where the fibers are to leave the "wire" for the next stage of their journey, suction-boxes are placed, provided with an air-pump to take up the surplus water that has not yet found its way through the meshes. Between these suction-boxes above the wire is a wire-covered roll which impresses the newly formed sheet; this impression cylinder is called a "dandy roll," and it is from this that the web receives the markings or impressions that characterize different papers. All watermarks, patterns, and designs which it is desired to have appear in the paper are put upon this roll and here impressed upon the soft sheet, which is clarified and left transparent at the point of contact. Thus the impression is permanently fixed in the fiber, so that it can be seen at any time by holding the sheet to the light. The power of suggestiveness is a quality which is highly esteemed wherever it is found, and which frequently furnishes a standard of judgment.
Judged by such a criterion, the impression cylinder, or "dandy roll,"
has an added value, for in all probability its operation suggested the idea of printing from cylinders, as in our present web or perfecting presses.