Scientific American Volume Xxiv., No. 12, March 18, 1871 Part 6

Of the skulls collected, it is sufficient to say that they belong to the "short heads," the length and breadth having a comparative medium proportion, a common form of cranium in the mounds of Tennessee.

Of stone implements I specify an ax of serpentine, ten inches long, two thick, and four broad, having plain sides and a straight edge ground down on both of the flat faces; hatchets ("tomahawks") of green stone, flint, and diorite, from five to eight inches long, with rounded faces and sides, contracted to an edge at one end, and to a flat heel at the other; a wedge of black slate, seven inches long and half an inch thick, of a square finish on the faces and sides and at the heel, which was diminished two inches, as compared with the length of the edge; hatchets with a serrated edge at each end, plane on both sides, convex on one face and flat on the other.

With one skeleton was deposited a "set of tools," eight in number, of the species of rock before mentioned, varying in length from two to eight inches. Their peculiarity consists in a variety of shapes--no two being precisely alike--and in their fitness to various uses, such as carving, hacking, paring, and grooving. The smallest of them, having a square finish, was held by the thumb and two fingers, and is suitable for cutting lines and figures in wood and sh.e.l.ls. Specimens of this art were furnished from the mound. The largest number might serve for hatchets, chisels, and gouges. One had been ground in the form of a cylinder five inches long and an inch thick, and then cut an inch on two sides to an edge, and worked into a handle with a round bead, from the center of the elliptical faces. It might be used for chipping wood and stone. One answered the purpose of a cold chisel; another was somewhat similar, but had a hollow face reduced to a curved edge for grooving. These polished instruments, wrought with much care, seemed intended for use by the hand rather than for insertion in a handle or socket, or attachment to a shaft by means of a strap or withe. Only one was perforated. The drilling through granite, quartz, and diorite, without the use of metal, was a severe labor, even for savage patience. A long knife of silex, with a wrought handle, lance heads, leaf shaped, of the same material, of beautiful workmanship, arrow points of fine finish, furnished, with others before mentioned, an a.s.sortment of arms. Several flint points, though only an inch long, were curved like a cimeter, and used probably as flaying instruments. True disks, of various mineral substances, from an inch to five inches in diameter, having convex faces, complete the list of stone implements. Those of bone comprise several like hollow chisels, sharpened at one end, and pierced through one face, near the other extremity, so as to be fastened to a handle; these were used for dressing skins. One was formed like a poniard, with a worked hilt.

With these may be connected arrow heads and sharp pointed weapons of the worked antlers of the stag, and tusks of the wild boar.

Of ornaments, I noticed pins used for dressing the hair, made of the columns of large sea sh.e.l.ls. The head is generally round, sometimes oval, from an eighth to a half of an inch in diameter, retaining the diagonal groove of the pillar from which it is made. The stems vary in length from one to six inches. It would be tedious even to cla.s.sify ornamental beads and b.u.t.tons of sh.e.l.l work, such as are usually found in the mounds. These trinkets are perforated, and, in addition to their being articles of dress, were used probably as "wampum," the currency of the recent Indians.

A miscellaneous collection includes a hemat.i.te stone, wrought in the shape of a cup weighing half a pound; when rubbed or ground it furnished the war paint of the savages; also the extremity of a copper tube, two inches long; needles in bone and sh.e.l.l, from an inch to six inches long, with grooves round the head, to serve the purpose of eyes; and plates of mica. The use of mica plates, which are found of large size in some of the Western mounds, has excited some inquiry.

Of a certain thickness, they make good mirrors. Beside their use for ornamental purposes, they were probably looking-gla.s.ses of the beauties of the stone age. There was also found a pipe of soap stone, having a stem five inches long, and a bowl with a broad brim, like a Quaker's hat.

Of earthenware, there was an endless variety of fragments of the usual black, grey, or red compressed clay, mixed with pulverized sh.e.l.ls or stones. One kind I have never seen described. The sherds had a red coating on both sides, an eighth of an inch in thickness, evidently not a paint or a glaze. The red coloring might have come from the pottery being burnt in the open air, instead of baked in a furnace, were not the layer of uniform thickness and of h.o.m.ogeneous paste, unlike the material of the vessel, which was a gray mixture of clay and particles of sh.e.l.ls.

I give the above memoranda to the general fund of information, touching a subject that invites inquiry on account of its novelty and ethnological importance. Every examination of the monumental remains of the ancient Americans brings to light some new feature in structure or type of rudimental art. And since archaeology has become a science, investigators, for half a century, may be looking about for facts to complete the system auspiciously introduced by the antiquarians of Northern Europe, and advanced in our own country by the researches of Caleb At.w.a.ter (_Archaeologia Americana_) and by those of the Smithsonian contributors to knowledge, especially Squier and Davis.

RAMBLER.

A SMALL WATER WHEEL.--There is in the town of Meriden, Conn., a Leffel double turbine wheel, running under 240 feet fall and driving a manufactory. It uses only about one-half of a square inch of water, and runs at the marvelous speed of 3,000 revolutions per minute, or 50 revolutions per second, which is by far the most rapid rate of motion ever imparted to a water wheel. This is, also, beyond comparison the greatest fall applied to the propulsion of a wheel in America. The wheel at Meriden is of the most diminutive size, scarcely exceeding in dimensions the old-fashioned "turnip" watches which our grandfathers used to carry in their capacious vest pockets. The complete success of this wheel has attracted much attention and affords further evidence of the wide range of adaptability of the Leffel turbine.

[For the Scientific American.]

SILK CULTURE.

BY W. V. ANDREWS.

A vague notion that silk culture ought to form one of the industrial pursuits of the American people seems to be prevalent enough; but it does not take practical hold upon anybody. The nearest approach to anything practical which we have seen, in late years--excepting, of course, what has been done in California--occurred in New York in July last, when a number of gentlemen pledged themselves, according to a report given in the _Tribune_ of July 30, "to promote the native silk trade."

The gentlemen present at the meeting represented the most prominent silk manufacturing and importing houses in this country. What these gentlemen have since done towards promoting the native silk trade, I do not know, but, having pledged themselves, it is presumed they have done something.

At the meeting, of which the _Tribune_ article is a report, dags, and other things, manufactured from California silk, were exhibited; and the report goes on to say that "Mr. Warren also exhibited samples of native and foreign coc.o.o.ns, and of raw and thrown silk, together with the common _Cecropia_ and _Bombyx Cynthia_, species of silkworms which feed upon oak leaves. * * Also the _Bombyx Yamamai_ which feeds upon mulberry leaves; also the _Bombyx Pernyi_, of which the coc.o.o.ns are early as good as the coc.o.o.ns of worms fed upon mulberry leaves."

I have given this extract, word for word, as it stands in the columns of the _Tribune_, because it contains more blunders of one kind or another than I remember ever to have seen in so many words. _Cecropia_ is certainly not very particular as to its food, but it is not an oak feeder. _Cynthia_ will thrive on nothing except ailanthus, though it will eat one or two other things, but not oak. The _Yamamai_, on the other hand, will eat oak, indeed it is its natural food; but Mr.

Warren errs greatly when he says that it will feed on mulberry. The last clause of the sentence, which says that coc.o.o.ns of _Pernyi_ are nearly as good as those of worms fed on mulberry leaves, must be a sort of entomological joke, of which the point is not discoverable by me, so I pa.s.s it over.

I do not, however, notice this report on account of its grammatical and entomological mistakes. It is because of the evil effects it may, and probably will, have on amateur silk culturists, that I notice it; for most a.s.suredly, failure will be the result of all attempts to produce silk coc.o.o.ns by feeding the caterpillars of the different moths on the food prescribed by Mr. Warren. Any patriotic, money making farmer, who believes in the _Tribune_, purchasing _Yamamai_ eggs and setting his worms to feed upon mulberry, which they refuse to eat, and consequently, all die, will probably give up silk culture as being nothing more or less than a humbug. And thus the cause is injured.

For several years past, I have made some experiments in the rearing of the silkworms, giving the result of my experience in the first year in Vol. II., page 311, of the _American Naturalist_; and of a subsequent year in the _Entomologist_, for November, 1869.

The paper in the _Naturalist_ is devoted to my experiments with the ailanthus silkworm, _Samia Cynthia_ (G. & R.), a naturalized species from the East. In that paper, I have said all that is necessary to say at present, on that species, except perhaps that I am further convinced, from the inspection of samples of sewing and other silks, made from the coc.o.o.ns of _Cynthia_, that one day it will be reared very extensively in the United States. It is perfectly hardy, is double brooded, and may be reared by any one possessed of a few acres of land, which may be good enough for growing ailanthus trees, but not good enough to grow any thing else. The labor of a few old men, or women, or even children, is sufficient for the purpose. The cost is therefore trifling.

The objection to the cultivation of _Cynthia_ is that the coc.o.o.n cannot be reeled. But it can be carded, and if the Chinese can make excellent silk goods from it, why cannot we? I suspect, too, that _Cynthia_ silk can be worked in with cotton, or, perhaps, woolen goods, adding to their beauty and durability (for it is indestructible in wear), and thus open up branches of manufacture hitherto unknown.

For manufacturers of coa.r.s.e goods, I have no doubt that the silk from our native silk moths, _Cecropia_ and _Polyphemus_, may be used.

Indeed, I believe that M. Trouvelot is of opinion that _Polyphemus_ may fairly enter into compet.i.tion with _Bombyx mori_, the ordinary mulberry silkworm. The worm, however, is rather difficult to rear.

In reference, however, to _Bombyx mori_, it is well known that the silk crop in France and Italy has been reduced greatly, and the price of silk goods consequently enhanced, by prevalence of disease among the worms. So much is this the case, that silk breeders have been obliged to look around for some silk-producing moths whose products may, at any rate, supplement the deficient crop. _Cynthia_, as already mentioned as one of these, and two others mentioned by Warren in the _Tribune_ reports above adverted to, are at present the subjects of experiment.

My article mentioned before as appearing in the _American Entomologist_ is mainly devoted to my experiments, and those of my correspondents, with _Yamamai_, which, as I said before, is an oak feeder. In j.a.pan, which is its native country, it feeds, in its wild state, on _Quercus serrata_. Whether that oak be found in America, I do not know, but it is of little importance, as the worm will feed on almost any species of oak, although I think that it prefers white oak.

The importance of acclimatizing new species of silk moths is of so much prospective importance, that I shall devote the remainder of this article to the consideration of whether _Yamamai_ and _Pernyi_ may not be naturalized here. Any one, who happens to have the number of the _Entomologist_ containing the article above alluded to, may find it worth while to read it, but as many persons may not be able to obtain that number, I will here repeat the substance of my remarks, adding as much new matter as subsequent experience has afforded.

The silk from the _Yamamai_ being considered superior to that produced by any other of the subst.i.tute silk moths, great efforts have been made in Europe to acclimatize it; but, it must be confessed, hitherto with but slight success. There are exceptions, however, particularly among amateurs in Germany, sufficient to show that success is possible. The Baron de Bretton raises about 27,000 coc.o.o.ns annually.

In this country but little has been done, or attempted, and that little has not been very successful.

The fact is, that _Yamamai_ is a difficult moth to rear in a country like this, where in early spring the temperature varies so much; but that success is possible, I am convinced.

The moth emerges from the coc.o.o.n in the latter part of the summer, copulates, lays its eggs, and of course dies. And now the trouble commences; that is, with eggs laid, say in j.a.pan, from whence we mainly get our supplies.

As soon as the egg is laid, the young larva commences its formation, which in a short time (about one month) is perfected. It lies in the egg in a quiescent state till early spring. If the egg remain in the country where it is laid, and is kept at a pretty even temperature, and free from damp, the caterpillar emerges in a healthy condition.

But if it be removed some thousands of miles, pa.s.sing in the transit from heat to cold, and back to heat again: and if, in addition, it be closely confined in a damp place, with little or no circulation of air, the egg is attacked by a fungus which sometimes prevents the worm from emerging at all; or, if it emerge, it is in a sickly condition.

That these conditions obtain in the transit of eggs, from j.a.pan to Europe, and thence to America, is evident enough; and it may, therefore, require the efforts of many persons, continued for a long time, to enable us to acclimatize the _Yamamai_. But this is all that is required, and I feel confident that ultimate success is certain.

On hatching out, the worm is of a brimstone yellow, and thinly covered with strong hairs; after the second month it is greenish, with black, longitudinal streaks, and the thread a dull coral red color. After the third month it becomes of a fine apple green, with yellow tubercles on each segment, from which issue a few black hairs. The head and legs are chocolate brown, the prolegs reddish, and the first segment edged with pinkish color. The greatest care is necessary, as the spring advances, to prevent the eggs from hatching before the oak buds are ready for them, and the temperature must be regulated with the greatest nicety. If the eggs can be kept somewhere about 50 deg. Fah., it would be quite safe; higher than that the mercury should not be allowed to rise, till you are quite ready for the worms, and, on the other hand, the eggs should not be allowed to freeze.

On emerging from the eggs, the worms should be allowed either to crawl to the oak branches, or rather to sprigs obtained for that purpose, the end of which should be placed in a jar, or bottle, of water, or the worms may be placed on gently with a camel-hair brush. The leaves should be well sprinkled with clean water that the caterpillars may drink.

From some cause, not well understood, the young caterpillars have a tendency to wander; and if care be not taken many may be lost. To prevent this, it is well to cover the branches with a gauze bag, tied tightly around the stems, and close to the bottle. Care must also be taken that the caterpillars do not find their way into the water, which they a.s.suredly will if they have the opportunity, committing suicide in the most reckless manner. If the number of caterpillars be few, it is a good plan to place them at the outset with their food, in a wide-mouthed bottle, covering the mouth with gauze. The branches, particularly if the weather be warm, must still be occasionally sprinkled, so that the caterpillars may have the opportunity of drinking. It must be remembered that experiment is necessary in rearing _Yamamai_, but one thing is ascertained, and that is, that the worms must not be exposed to direct sunshine, at least not after seven or eight in the morning. If the spring be warm, I am inclined to think that a northeastern exposure is the best, and we may sum up by saying, that comparatively cool and moist seasons are more favorable to success that hot, dry weather. In America the worms suffer in the early spring, from the rapid changes of temperature, 40 at 9 A.M.

increasing to 70 in the afternoon and falling off to freezing point during the night. The worms cannot stand this. They become torpid, refuse to eat, and consequently die. To prevent this, if the nights be cold, they must be placed where no such change of temperature can occur.

It is scarcely necessary to say that an ample supply of fresh food must be always supplied, but it may not be amiss to say that it is well, when supplying fresh branches, to remove the worms from the old to the new. The best way of doing this is to clip off the branch, or leaf, on which the worm is resting, and tie, pin, or in some way affix the same to the new branches. If this be not done, they will continue to eat the old leaf, even if it be withered, and this induces disease.

If the worm has fastened itself for the purpose of moulting, the best way is to remove the entire branch, clipping off all the dried leaves before so removing it. These remarks apply, in general, to the treatment of all silkworms, except _Bombyx mori_.

The results of numerous experiments with _Yamamai_ go to show that it is, as I said before, a difficult worm to rear; but it has been reared near New York to the extent of eight hundred coc.o.o.ns out of sixteen hundred eggs, and this, although not a remunerative result, is encouraging.

The Chinese silk moth, _Aulterea Pernyi_, also an oak feeder, has been successfully raised by me and by others, for several years. Eggs have been sold to persons in States widely separated, and the results show that this worm is perfectly hardy.

The moth winters in the coc.o.o.n, emerges early in May, if the weather be warm, pairs readily, and lays from 150 to 200 eggs. These hatch out in about fourteen days, and like _Yamamai_, always about 5 or 6 o'clock in the morning. It is necessary to be on the alert to catch them on hatching only, and to remember that they are vagabonds, even to a greater extent than _Yamamai_. Consequently similar precautions must be taken.

The worm on emerging from the egg is large, and of a chocolate-brown color. After the first month it becomes of a yellowish green; head, pale brown; feet and prolegs of nearly the same color. The body has numerous reddish tubercles, from which issue a few reddish hairs. At the base of some of the tubercles on the anterior segments are silvery patches.

The _Pernyi_ worm is much more easily reared than that of _Yamamai_, but still great care is needed; fresh food of course is essential, and a slight sprinkling of the branches and worms in very warm weather is advisable; although it is not so necessary as with _Yamamai_. It is remarkable that _Pernyi_ worms, fed in the open air, on oak trees, do not, at present, thrive so well as those fed in-doors, but this, doubtless, is a question of acclimation. I advise white oak (_Quercus alba_) as food, if it can be readily obtained, but failing that, pin oak (_Quercus pal.u.s.tris_) will do; and I have no doubt that they will feed on any kind of oak. They will, indeed, feed on birch, and on sweet gum (_Liquidambar_), but oak is the proper food. It is worthy of remark that _Pernyi_ bears a strong resemblance to our _Polyphemus_, but it is more easily reared in confinement, and double brooded; an important fact for the silk culturist. From American reared eggs, I obtained coc.o.o.ns as early as July 4th, the perfect insect emerging on July 31. Copulation immediately ensued, and the resulting eggs hatched only on August 12, ten days only from the time of laying; and as the worm feeds up in about four or five weeks, this affords plenty of time for rearing the second brood. It must be remembered that on the quant.i.ty and quality of food, much depends, not only with _Pernyi_ but with all caterpillars. By furnishing food sparingly the time of feeding would be much prolonged.

I have already said that both _Yamamai_ and _Pernyi_ should be fed under shelter for the reasons given, but there is another reason of less importance. The young worms are liable to be attacked by spiders and wasps, and even after the second month, they are not safe from these enemies. I have seen a wasp bite a large caterpillar in two, carry off the anterior section and return for the posterior, which had held on by its prolegs. Did the wasp antic.i.p.ate this fact, and therefore carry off the anterior part first? As to the spiders, they form a series of pulleys and hoist the caterpillar off its legs, sucking its juices at leisure.

And now I must devote a few words to the advisability of silk culture from a pecuniary point of view. _Bombyx mori_, or the ordinary mulberry silkworm, is, of course, the best to rear, if you can obtain healthy eggs. But this is the difficulty, and thence arises the necessity of cultivating other silk-producing species. I imagine that silk can be produced in most of the States of the Union, and manufactured from the coc.o.o.n at a large profit; but for the present, we will leave the manufacture out of the question, and consider only, whether it will not pay to rear eggs and coc.o.o.ns for sale? It must be remembered that European manufacturers are at this moment largely dependent on foreign countries for the supply of both eggs and coc.o.o.ns; and this, because of the general prevalence of disease among all the races of _Bombyx mori_. And now, to what extent does the reader suppose this dependence exists? Of coc.o.o.ns I have no returns at hand, but, of raw silk, European manufacturers purchase, annually, not less than $160,000,000 worth; and of eggs (_Bombyx mori_) to the value of $10,000,000. This, then, is a business of no trifling amount.

California seems to be alive to the fact, and, I am informed, raised, this last season, $3,000,000 coc.o.o.ns; and, for sale, about 4,000 ounces of eggs, worth at least $4 per ounce, wholesale. Now, there is no earthly reason why California should monopolize this business.

Why are not companies formed in other States for this purpose? or if private individuals lack the enterprise or the means, why do not the legislatures, of those States most favorably located, do something by way of starting the business? A few thousand dollars loaned, or even donated, may prove to be a valuable investment for the people at large, and, even supposing a failure, would not be a very great loss to any body.

So far as farmers are concerned, it may interest them to know that one man in England, Capt. Mason, clears $50 per acre by rearing silkworms (_Bombyx mori_ in this case), and I much doubt whether any crop raised here pays as well.