T H E J O U R N A L OF I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y steel fluctuates. However, it is usually estimated that a cooking method plant will cost, approximately, $1,500 per rated ton with steel a t 3 cents per lb., while the cost of a Cobwell plant will be about one-third more than this. I n net recovery values it is generally stated that for the cooking method $2.00 per ton is a fair average, while Cobwell gives, approximately, $I .oo more per ton. The only safe method of estimating is to analyze the material in each case. I have no definite figures as to the drying method. While in most of the cities the disposal of garbage is done by contract, and in the majority of cases a bonus is paid to the contractor, the following cities receive payment from the contractor:
. ...., ...At the rate of about 45 cents per ton . .... . A t 51 cents per ton
New York.. Los Angeles..
Minneapolis has just closed a contract for pig feeding a t a revenue of $1.26 per ton, and Richmond, Va., under the same system, expects to receive $2.00 per ton. Denver was the first to adopt pig feeding under contract, without the payment, and is doing so a t no cost to the city nor is anything paid to it. These figures appear very attractive, but it is well to be conservative as to the expected revenues from this source, as this system is, as yet, under trial and the result of the experiment will only be assured when a renewal of such contracts show that the contractor has been successful in operating under such a method of payment. An inspection of successive reports from the cities which operate municipal reduction plants gives a very good idea of the uncertainty of the revenue derived from year to year. I am very much impressed with the patriotic purpose evidenced by this association in giving so much of its valuable time to the study of the subject of municipal waste disposal, with the intention of performing a civic duty in endeavoring to promote more efficient methods and better financial results, if possible, through the employment of the high professional skill of Jts members, and I, therefore, take the liberty of calling your attention to the fact that the United States Food Administration recommends that a t this time such energy be used in obtaining more efficient operation of existing methods rather than the evolution of new methods. COHWELL CORPORATION 50 CHURCHSTREET NEWYORKCITY
AMERICAN GARBAGE DISPOSAL INDUSTRY AND ITS CHEMICAL RELATION‘ B y RAYMOND WELLS
I t is undoubtedly true that before the world war there were chemists in this country and that they were doing most wonderful and useful work, but we were so bewitched by the work done by German copyists and grinds, that when the awakening came, we were astonished to find that the animals a t home were likewise endowed with horns and of no inconsiderable magnitude. At once every industry that had ever thought of the possibility af chemical assistance obtained three of this rare species, and those that had never thought of it a t all clamored for a t least one. Every business, industry, and manufacture wished for this strange new thing-“scientific control,” obtained it as best it might, and found it good. Of course there may be some things the chemist cannot do, but they do not exist in the popular mind. An industry a t this date without a chemical advisor, director, or, a t least, a plain ordinary “lab. man” is in the same class with the great auk, and yet there have been explorers who have claimed to have seen specimens of this rare bird, even a t the present time. I t does not take an explorer t o locate the Remarks following Mr. Very’s paper, New York Section, American Chemical Society, May 10, 1918.
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“garbage industry,” but it might prove a stiff task for anyone without the natural instincts of the lowly ferret to find more than one or two even “lab. men” in the business, leaving out of consideration a “regular chemist.” An industry has grown up in this country, taking care of the household table and kitchen waste of 17,000,000people, serving twenty-nine large cities and returning an annual revenue from the by-products of this service amounting t o $II,~OO,OOO. A t the same time disposition is made of 1,200,000tons of raw garbage, from which, disregarding the monetary return, t h e nation is the richer by producing from its own so-called waste 70,000,000lbs. of grease and 175,000 tons of valuable fertilizer. And such an industry is practically without a chemist or without even being given recognition by chemists as being one of the few unexplored fields, for their efforts, a t the present day. The disposition of garbage with recovery of the by-products. is essentially a chemical problem and its neglect has been due to several causes. The attitude of all or of practically all men or corporations engaged in the business, has been one of antagonism toward chemists, either as individuals or as representatives of science. They were not very unreasonable in this, since all of those chemists attempting t o work or t o improve the garbage business, did so by long range treatment of garbage as it ought t o be from a theoretical standpoint, and from their knowledge of some other business in their mind similar t o it. It is not like any other business under the sun, so they fell down most lamentably and the so-called “practical swill man” stood off and scoffed. The “swill man,” satisfied with partial success, with sometimes. profit and sometimes loss, but with the profit just enough in the right pan of the balance t o keep the attraction always there, did not like the idea of disturbing things which had been done, and was thus prevented from asking anything of science. His whole attitude has been one of secrecy about the simplest of operations and one of horror a t the idea of starting anything which might or might not turn out to their pecuniary advantage. Don’t blame the swill man for his attitude. He set out t o make something out of nothing, out of something which everyone turned away from, about which no one knew anything, and in approximately thirty years built up a real industry, without assistance from anyone. It was all “try it and see,” and after a period of several years something was arrived at, which was. moderately satisfactory and sometimes made a little money. After that, why change? Changes meant increased investment, possible big financial failure-better to jog along and keep quiet, taking all that could be obtained and when not obtained, slip it over quietly to the next chap. Seeing this attitude and not looking into what promised only t o be a dirty, disgusting hot, sweaty business, where things, were accomplished by rather circuitous methods a t times, viewed from political and engineering standpoints, the chemist withdrew to more savory and apparently more promising fields. As a matter of fact he chose, as usual, the line of least resistance. In spite of thi‘s neglect from the chemist, the business has prospered and is doing very excellent work for the city and for the nation. A short time ago the city and the nation woke up to the garbage situation and were surprised to find that a real industry existed. Immediately propaganda started and continue to start, which is well, for out of them may grow an interest both popular and scientific, valuable to the industry and t o the nation. Before venturing too far in denouncing our nation as a nation of wasters and as a nation neglectful of its waste materials, it is well to consider all of the facts in the case. For instance, the largest city in the United States has the largest garbage plant in the world and the most up-to-date one from the chemical and engineering standpoints, representing the effort and financial hazard of many men. This plant possesses the sine qua non of the swill business, i t is sanitary and does not
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T H E JOCXAV.4L O F I i V D C S T R I A L A N D ELVGIi\iEERING C H E l M I S T R Y
commit a nuisance either in the legal sense or actually. I t takes care of the waste food material from 6,000,000 people, amounting even a t the present time of conservation, t o an average of Boo tons daily or 320,000 tons per annum. Not one particle of this material is wasted. Only the water is eliminated and that as distiJled water. I n one operation the garbage is transformed or separated into I~,ZOO,OOOlbs. of grease of a value of $Z,ZOO,OOO and a t the same time 64,000 tons of tankage of a value of $I,OOO,OOO are produced. Several other items, as rags, bones, etc., give an additional value of several hundred thousand dollars. Aside from the money value, this grease recovery means to the nation 1,344,000 lbs. of “dynamite glycerin” and over I~O,OOO,OOOcakes of soap. The fertilizer value of 64,000 tons of tankage makes fertile many acres, a t a time when the nation is starving for fertilizer. This grease all enters the soap, candle, and glycerin industry and constitutes no small source of supply, and the fertilizer manufacturer regards garbage tankage as a most valuable “base goods.” These materials are in no sense low grade and they find a ready market. This one plant employs several hundred men and consumes daily zoo to z j o tons of coal and 3000 to 4000 gal. of kerosene. Kerosene is used for percolation on a huge scale, an innovation in the percolating line which no other industry conceived of or dared to try on a large scale. When it is noted that in the regular course of operation 300,000 to 400,000 gallons of solvent are in constant use, and that still capacity for solvent recovery of joo,ooo gal. actual operating capacity per 24 hrs. is required, then one can realize what the industry in one plant means. This is the largest of zg garbage reduction plants in the country. All of our largest cities have them, only a few of the mediumsized cities still being unenlightened and sticking to the prehistoric and very European method of expensively burning valuable material, These twenty-nine cities produce the quantities of material mentioned in a preceding paragraph. Not all of them have perfect plants, not all of them utilize all of the values in the garbage, but they are performing a public duty and doing it efficiently, as far as their equipment makes it possible. It is hoped that the preceding statements may lead to the realization that a big industry of great value, not only from the conservation standpoint, but from that of public service and health, has been built up quietly and without attracting, till this time, any public notice or any notice from the scientific world. The industry is doing very well, it has improved much after a sleep of twenty-five years, it has a t last a real method, now operating four years, which is the best yet and promises to be better in the near future, but even now the whole business is nothing more than a healthy embryo, which will require many years of patient work on the part of many patient chemists to incubate to a real live animal and then it will have to grow. ANALYSISOF SAXPLE
AVERAGF: HOUSEHOLD GARBAGE Per cent Moisture, .................... 71.00 4.54 Grease. . . . . . . . . . . . . . . . . . . . . . . 4.24 Protein. . . . . . . . . . . . . . . . . . . . . . 2 . 17(a) Ash. . . . . . . . . . . . . . . . . . . . . . . . . . 3.21 Fiber. . . . . . . . . . . . . . . . . . . . . . . . Cane S u g a r . .. . . . . . . . . . . . . . . . . 0 . 7 7 Invert S u g a r . .. . . . . . . . . . . . . . . . 0 . 5 0 Starch, Dextrin, e t c . , . . . . . . . . . . 1 0 . 4 6 0.23 Alcohol. ..................... Acid as Acetic.. . . . . . . . . . . . . . . 0 . 1 7 Essential Oils. . . . . . . . . . . . . . . . . . . . Ethers, e t c . . . . . . . . . . . . . . . . . . . . 0 . 1 1 ( a ) Potash, bone phosphate, lime, silica, etc OF
That it is a chemist’s problem the foregoing analysis will demonstrate. Garbage is a conglomerate of all the odds and ends of all the things which men eat, a mixture of every naturally occurring organic material. Think of it in terms of
V O ~ I.O , NO. 7
this typical analysis and see if it does not suggest opportunities. This analysis does not total IOO per cent, since none of the determinations were made “by diffe;ence.” The opportunities suggested by such a mixture offer for research almost virgin soil. And this field has never been touched by our erstwhile German rivals. A nation which is lucky to get garbage to eat, has no garbage problem to solve. Many urge that we too should have no garbage cans. It may be so some day, but not for several generations and it is a very nice question, whether with proper methods of utilization, i t may not be as economically profitable to so utilize it and not attempt to force on the human anatomy that which is unattractive and unpalatable. It may be better to let a mechanical digestive tract turn less easily digested materials into substances of greater value for other purposes than for food. Maybe i t is better to throw away rancid fat, tough sinews, and potato parings and have the same come back as soap, fertilizer, and alcohol and eat the vegetable oils, animal fats, and the grain released by such an exchange. Nothing is ever destroyed. It can be badly mixed up and out of place, that’s garbage. It is the duty of science to put it back into place, and chemistry is the one science most urgently called upon. HOMER,N. Y .
THE POTTERIES AT SHEK WAAN, NEAR CANTON, CHINA By CLINTON h-. LAIRD Received March 12, 1918
The prevalence of white ants in South China restricts the use of wood as a building material to a minimum, and therefore all but the most temporary structures are built of brick with tile roofs. The bricks used range from sun-dried, in the poorest villages, to well-burned gray or red of various dimensions. They are made a t many different places. The tile are of two kinds, a pan tile, g in. square, curved like a shallow trough, and a round tile, approximately half of a truncated cone. The latter are laid in rows over the joint between the vertical rows of overlapping pan tile. These round tile are often glazed but the pan tile very rarely. Most of the common unglazed tile, of different grades, used in and near Canton, are made in Fa Uen district, about 30 miles north of Canton. The only place where any glazed roof or fancy tile or other glazed earthenware articles are made in South China is a t the village of Shek Waan, about 20 miles west of Canton. The pottery industry there is said to be over 700 years old. When the process for glazing earthenware was developed is not recorded, but as one of the temples in Canton has a glazed tile roof (never relaid and still in good condition) known to have been laid 400 years ago, the process is not one of recent origin. At this village are made earthenware jars and dishes of all kinds, clay idols and figures of men and animals, and, in recent years, tile pipe, as well as the glazed ware of many kinds, in color chiefly brown, green, blue and yellow. For some unknown reason or reasons, possibly through consideration of both beauty and expense, the use of colored glazed roof tile was restricted long ago t o temples and imperial buildings. Other blue and green articles made of the same materials in the same way have had a wide use in private buildings, and after the First Revolution (1911)the restriction on the use of glazed roof tiles was removed. General use, except by foreigners, will probably not become common for many years, however, because of the strong association between the tiles and temples. I have been told by one who has travelled widelyin the interior of China, that the only place he has seen the green roof tile used on buildings other than temples is a t Peking where they are used on the tombs of the imperial concubines. The imperial buildings in
