Copyright N° COPYRIGHT DEPOSIT: Te iV’ SUCCESSFUL INCUBATION A WORKING MANUAL FOR LARGE HATCHING PLANTS ar apse By P. COOK PROPRIETOR OF THE MAMMOTH HATCHERY LOS ANGELES CAL, PRICE, $1.00 NET PUBLISHED BY THE WEIMAR PRESS 8015 8. MAIN ST., LOS ANGELES,CAL. Copyright, 1911 By P. Cook. € CLA280782 PREFACE This little book gives our experiences in hatching conducted for about six years. It is the story of our investigations, how we have finally stumbled on to the right way to hatch chicks. It is hoped it will save many the heart-rending experiences we have gone through. When you once know how, it is simple enough to hatch chicks, but it is not always easy to find out the simple way. We also hope that there will be no disappointment to our readers. It seems that most poultry books are written by persons sitting by a cosy fire spinning theo- ries that are utterly impracticable. This book is based on actual hatchery work and every effort has been made not to mislead any one or make claims unsupported by actual facts. But there is still room for improvement and we shall be glad to hear from our readers if difficulties persist. All letters to me should be addressed to the publishers of the book, and they will be forwarded. The price of the book may seem high to many per- sons, but it costs a great deal to publish a book. It is not the paper it is printed on, but the advertising that costs, and it is more than doubtful whether the pub- lishers will ever be adequately paid for it even at its high price. It contains real information, that will be worth tenfold its price to any reader even the first year he uses an incubator. Moreover, it must be remembered that all the inven- tions of this book are given free to the public, there are no patents on any of them. Everybody is at liberty to use what he likes. The proceeds from the book is the only remuneration the author receives. P. COOK. Los Angeles, Cal., Jan. 1, 1911. (92ed JXON] 29098 UOQALISo(] 40 J) YOLVAENONI $.MOOS ‘d JO WVYOVIG pi | | 154 “~yv + ' a : S% VERS re CRS oees ORS WBN ans KOKA d Da Lit: 0 % Caide ee aie Me PROX ; DESCRIPTION OF P. COOK’S INCUBATOR (See Diagram on Preceding Page) Fig. 1. a, jacket enclosing boiler. This communi- cates with the outer air around its lower rim. The air thus heated by the sides of the boiler passes into the upper compartment of the incubator through the open- ing e, during incubation there is no other ventilation. It will be seen at once that this method procures a great deal of superheated air, which helps to take care of the evaporation from the eggs without unduly increasing the humidity of the egg-chamber. b, small tubes through which heat from the lamp, y, passes through the boiler, c, when the damper of the regulator is down. When damper is raised, the heat passes directly from the lamp through the large centre tube, 0, without heating it, n, ‘is a collar or rim compelling the heat from the lamp to ascend through small tubes, instead of dissipating be- low the boiler; f, portion of return pipe from incubator; d, portion of outflow pipe or coil entering incubator; h, thin muslin diaphragm separating upper and lower com- partment of incubator, preventing any draft from air en- tering at e; k, egg tray; i, nursery; m, incubator legs; p, ventilating tube, used to dry off chicks after hatch- ing. Kept closed during incubation. Fig. IJ]. r, incubator; s, drawer containing nursery and egg tray; t, stick on which drawer rests when pulled out. Note.—All the experiments and successful hatches de- scribed in this book have been made with machines con- forming strictly to this type. We have so far found this the most successful type, and used it equally well with hot air as with hot water heating. INCUBATOR INSTRUMENTS P. Cook's Carbonic Acid Gas Test, complete set of all neces- sary instruments, $5.00 P. Cook's Hygrometer, continuous reading, $3.00 P. Cook's Simplified Hygrometer $1.00 postpaid (No one using an incubator should be without at least the Simplified Hygrometer. The other instruments are for large hatcheries.) For sale by P. COOK, 3017 S. Main St., Los Angeles, Cal. Note to page 21---No carbonic acid gas is given off by the ody of the hen. We have made many tests to that effect. All that is found under her comes from the respiration of the embryo. SUCCESSFUL INCUBATION SOME EXPERIENCES WITH INCUBATORS. Some of the strangest experiences take place with in- cubators. We have had our share of them. The very first incubator we bought happened to be a good one, and we had reasonably good hatches out of it, yet a considerable proportion of the chicks died in the shells. We supposed that with more experience we would be able to get better hatches, but the contrary proved to be the case. After two hatches we moved this incubator to another building, and we had nothing but poor hatches from it in spite of the best of our care, so we gave up that kind of an incubator. Then we heard of one that was producing very good hatches through an ac- quaintance, and we invested in that make, but it would not hatch for us in any way at all. We tried it six or seven times, and lost practically every hatch. Then it was moved to another room, and as we were badly need- ing an incubator to take care of some surplus eggs, we decided to run it once more, and the machine has given very good hatches to the present date, standing in this one place. In the meantime we also built different types of in- cubators of our own to find out, if possible, the difficulties in incubation, and though we constructed over thirty different types of machines, and tried almost every con- ceivable method we did not seem to make any particu- lar headway. It was always the same old story, some- times a very good hatch, and then a number of very bad ones. We tried it three times with one very popular make of incubator, and in each hatch as many chicks were dead in their shells as those that succeeded in get- ting out. We sold the machine in disgust. The man who bought it from us moved it to his house, and the machine hatched every fertile egg, although he had never run an incubator before. We had another machine which we built ourselves that gave a very remarkable hatch, and we hoped we were nearing the goal. We moved it to another room in our hatchery, and it would not hatch there at all. And more perplexing still was another case of a ma- chine holding about 1000 eggs. It had four drawers, and the two drawers in the rear end of the machine always hatched very well. The two drawers in the other end of the machine, while the temperature was the same throughout, never hatched at all, i. e., most of the chicks died in the shell, or were cripples, though it was im- possible to discover any difference in the machine. Another peculiar case we had was this: Someone brought us some eggs on which a hen had set for four 7 days, and then died on the nest. It was about 18 hours after the hen was dead that the eggs were brought to us, and the eggs were stone cold when they arrived. We placed them in an incubator with 300 eggs in it, which had been set just about the same time. At the time of hatching we secured nine strong, lively chicks from the eggs the hen had set on, and there was only one egg which was fertile that failed to hatch of the hen’s clutch, but the 300 in the incubator practically did not hatch at all, i. e., there were about fifty miserable chicks that got out. The rest did not get out of the shell at all. We have tried a great variety of different makes of machines, and we have had the same story with all of them. Sometimes they hatch very well, and sometimes they do not hatch at all. Most of the time there are more dead chicks in the shell than there ought to be with all of them. Some machines are far better built than others, but even the poorest made machines have given us just as good hatches, as the most expensive ones. The glowing testimonials which all the incubator man- ufacturers send out are probably genuine, as we could duplicate most of them once in a while. Nearly every make of machine we have seen sometimes give as good hatches as claimed, but there is always against the one success a woeful lot of failures. Of course, if eggs are exceptionally strong and vigorous in fertility, they will perhaps hatch under almost any conditions, but the great necessity for poultry raising is to get an in- cubator that will hatch nearly as well as the hen, and in all our experiences with the hens we have found that, barring accident, she succeeds in hatching practi- cally all the fertile eggs. We soon became convinced, of course, that something must be wrong with the in- cubator, but the harder we tried to find out the farther we seemed to be from the goal. It is easy to build a new incubator, and build one that one thinks is a great improvement. Ninety-nine times out of one hundred it will be found, however, that the new machine is worse than the old one. It is needless to rehearse the whole history of our experiences. I simply mention these things to show that in the way incubators have been constructed hitherto some vital things have been lacking, and if anyone has experiences similar to these, he must remember that every other poultry man is apt to find such happenings some time or other. It is true, some poultrymen have been singu- larly fortunate in having almost always good hatches, and others have been singularly unfortunate, in al- most always having very poor hatches. However, we think that, in the following pages we describe a method which will enable anyone to secure hatches nearly as good as those the hen produces. So far as we know we have good reason to believe that the essential principles of incubation have been discov- ered, and the only thing that remains to be done is to 8 reach a greater perfection of our method. At any rate, the only way to discover the right method is by un- ceasing experiments, and we shall be very glad if persons who follow our method will report to us the success, or lack of success, which they have. We hope for the heart- iest co-operation in this respect, as the first principle in successful poultry keeping, is the successful hatching of strong, vigorous chicks. It is certain that in an incubator where fifty per cent of the chicks die in the shell, the chicks that actually do get out have not been incubated under desirable condi- tions, and must have suffered considerable, which means that they are handicapped from the first. It is an unfortunate thing that it is almost next to impossible to have people willing to acknowledge their failures in hatching. Every body seems to think it a disgrace to acknowledge the unsuccessful hatching of his eggs. It is time that there be a little more honesty among poultry men in this respect, and if anyone has discovered a successful way of hatching he should be willing to let his neighbors know it. We believe that we have made very important discov- eries and therefore publish this little volume, but we de- sire to have it taken as an incentive to more careful ex- periments, much rather than as an entire solution of the problem. The most careful methods are necessary for this in- vestigation, and much patience must be exercised, but ‘the fact that eyery once in a while an incubator pro_ duces perfect hatches shows beyond a doubt that the goal of unfailing success is attainable, and if we are patient enough and work hard enough we shall finally wrest from nature her secrets. HOT WATER OR HOT AIR INCUBATORS. We have used very extensively in our tests, both hot water and hot air incubators, and so far as the hatching of eggs is concerned, it makes not the slightest difference which is used, providing it is constructed properly. Manufacturers of hot water machines should see to it that their hot water tanks are well made, and especially should avoid any combination of galvanized iron with brass or copper, as these are sure to leak in a very short time, on account of electrolysis. We should advise, however, for all small machines, the use of hot air, as we have found in our experience that it gives much less trouble. If once such incubators are built right, they last practically a life time. The heat is not as even in a hot air machine, as it can be made in a hot water machine. But a little unevenness of heat seems to be of no importance. The hot-air machine is less trouble to take care of than the hot water machine. However, the hot air machines can hardly be built suc- cessfully to take care of more than 500 eggs. If larger machines are to be used, hot water is required. 9 We have also experimented with a great many differ- ent boiler systems, but find a copper boiler with a large tube through the center, and a series of small tubes run- ning parallel with it between the large center tube and the sides of the boiler, to be the most successful. The damper is placed over the large center tube connected with a thermostat. When the damper rises, the heat from the lamp or gas flame passes directly through the center tube without heating any water in the _ boiler. When the damper is closed the heat passes up the center tube and returns through the smaller tubes before find- ing an outlet, thus giving an immense heat surface. The requirements for incubator boilers are that they should have an immense heating surface when the dam- per is closed, and when the damper is open none, or at least only a very small amount of heat should pass to the boiler. The best circulating system we have found to be wrought iron pipe connected in the ordinary way to the boiler, but the outflow pipes should be connected to the top of the boiler, and the return flow should enter the bottom of the boiler. The boiler always must be placed somewhat lower than the outflow pipes. In our practice we place the outflow pipes at the top of the boiler, and let them rise gradually about one inch, or sometimes two inches to the extreme back of the ma- chine, and then let the return pipe have a fall of about two inches through the length of the incubator, and then let it pass down to the bottom of he boiler. It does not make any difference how far the highest point of the pipe is from the boiler, as hot water will rise to the top, but there must be an even fall from the highest point to the return, in order to insure good circulation. In hot air machines the difficulty is to spread out the heat toward the sides. There are several ways which seem to do the work equally well, and a number of differ- ent systems are in use on the incubators on the market. We cannot see that one has any advantage over the other. HINTS TO THE MANUFACTURERS OF INCUBATORS. Incubator Case, Doors, Etc. There are very few incubators on the market at the present day that are built sufficiently well for the pur- pose for which they are intended. Many incubators are built so cheaply, and in so slovenly a manner that no man who cares to hatch eggs should ever be tempted to buy them, no matter at what price they are offered. They are too expensive even if they were given away. The first requirement for success in raising poultry is to hateh strong and vigorous chicks, and unless an incubator is well built, you cannot possibly do this. It is not the ma- terial that is used in the incubator which is of so much consequence, but the workmanship in putting it together is of the very greatest importance. Every incubator 10 should be built of double walls throughout, and at least on top, should have a thoroughly heavy packing of heat insulating material. But more important than the pack- ing is the care with which joints are made. They should be made on proper machinery and carefully glued together, so as to make the incubator case air-tight, es- pecially the door should be made to fit absolutely air tight. This is almost impossible to accomplish unless the edges of the door and its casings are lined with felt. There should be double doors, one glass door next to the eggs, and outside of that a solid wood door. This is preferable, for if chicks are kept in the dark while hatching they will remain evenly scattered over the in-_ cubator. If there is only one glass door chicks will all crowd to the front. This may be obviated somewhat by placing the glass high up in the door, and leaving a con- siderable dark space at the bottom, which keeps the light out of the nursery. But far better than the arrange- ment of glass doors, and egg trays is the method of con- struction used in our Mammoth machines. These have simply a large drawer, which fits tightly in the machine. The egg trays are placed within this drawer, near its top, and for airing the eggs, the whole drawer is pulled out of the machine resting one end upon the incubator, and the other on a stick fastened to the front of the drawer. A small window screened with curtains is cut in the upper part of the drawer through which the tem- perature may be read, and chicks may be watched at the time of hatching. This arrangement saves a very large amount of labor, as the chicks can easily be gotten out, and the eggs are always protected from drafts, as the sides and bottom of the drawer are solid, and thus pre- vent any drafts from striking the eggs. THERMOSTAT, LAMPS, HTC. It is immaterial what kind of thermostat is used, whether it be composed of different metals, or ether wafers. Everything here, as everywhere else, depends upon the care with which they are made. Wither kind will last a life time, if well made, but it is quite important that ali the bearings should have knife edges and should be patterned after the method of bearings used in weigh- ing-scales. When possible only one direct lever should be used, and the method of regulating the heat should be that which is commonly known as the damper method. Any thermostat working on the wick of the lamp is always more or less unreliable, as the wick sleeves are sure to char some time or other, and thus prevent its working. While there is a little saving of oil on the lamp trips, they are sure to spoil the hatch sooner or later, and thus may be expensive in the end. Lamp bowls should be made either of galvanized iron or copper or brass, and they should be well and strongly 1] made, and the upper part of the lamp bow! should be per- fectly smooth, sloping toward the edges, so that no oil will stand on it. If the boiler of the incubator is constructed properly, arrangements to keep water on the lamp, or around the flame are unnecessary, and had better not be used. The final outlet of the bad air from the lamp should be at least twelve vertical inches above the flame, no matter how far endways, or sideways this outlet is found. Other- wise there will be heating of the lamp flame, and of the lamp bowl, and there is danger of generating explosive gases. Lamp chimneys should be made of iron with a large mica window at least 2 inches in diameter, but see that your chimneys are faultlessly made, for drafts from the chimneys will cause the lamp-flame to smoke, and be- come dangerous. The lamp on any incubator should be carefully locked. No spring arrangement is ever to be allowed, for springs, no matter how good they are, will get weak in a short time, and the lamp will not fit prop- erly. The lamp should be so securely locked to the in- cubator that it cannot be knocked off; even if the incu- bator should be overturned the lamp should still stick to it. To encase the incubator in metal is useless, the danger comes from the lamp, not from the incubator. Common sense requires these precautions. Thermostats should have a protective covering so that cats and dogs, or children or plaster that may fall from the wall on them, would not throw them out of position. It is to be remembered that any thermostat must of ne- cessity be a delicate instrument, and it should be made accordingly, and treated accordingly. CARE OF BREEDING STOCK AND FERTILITY OF EGGS. We have used eggs from birds kept under all sorts of conditions. Birds that have run on the wide range, and birds that for several years have been confined in very small pens, also eggs from birds fed on pure grain and birds that were fed on nothing but garbage. We have not been able to detect any difference in the fertility, and vigor of the embryo in the eggs, as far as external condi- tions and feeding of stock is concerned. More seems to depend upon the vigor of the fowls, and especially the males. Males should have a rest some time during the year, or should be interchanged with others. This much, however, is certain, that birds kept on a very large range have the best chance of producing vigorous strong germs in the eggs intended for hatching, but it must remain for further experiment whether confining birds or diff- erent methods of feeding affect the vigor of the embryo in the eggs. 12 CARE OF THE EGGS. One of the first requirements for successful incubation is the proper handling of the eggs. Eggs should be gath- ered as soon as they are laid, and not exposed to the heat or bright sun. They should be carefully placed in the ordinary market egg cases, and should be kept in a cool place (55 degrees), but under no circumstances should they be exposed to draft of any kind. The fresher the eggs are, the better they will hatch. If it is expected to hatch every egg that is placed in the incubator, no eggs over three days old should be used. However, we have sometimes had reasonably good results from eggs that were three and four weeks old. There is a popular idea that eggs intended for hatching should be turned every day. We doubt very much if this does them any good. It is of much more importance to handle the eggs very gently, for the jarring and shaking of them is a heavy strain on the various membranes of the egg. Violent shaking of the egg will destroy all its possibility for hatching, and the less eggs intended for hatching are handled, the better it is. If eggs have become soiled, they should be washed, but it would be better not to use any eggs that have been washed, or subjected to any unnatural conditions in any way. 47 35 oe 15 103 120 8 85 47 15 16 103 80 8 83 42 15 17 103 50 9 84 45 15 is 103 40 10 85 47 15 19 103 40 10 85 47 Eggs pipping 20 103 50 9 92 68 Hatch half out 21 103 40 10 84 45 Hatch all out ee RECORD OF TWO HENS : 1 2 1 2 tncube- || Vol. Air | Gas | Vol. Air | Gas Wer | Mois hen of gL (rR eS aaa ae PAG bg hige cae Jeg 5 3 Rie 4 ee RS NSIS By lta Pega nag 6 [8 86 | 49 7/8 al ee 8 |§ Slag (cada fb ai 10 | i Eel aaa 11 |S fda Ne a 12 |s roy EL 13 = a ORE ea ee ¢ 14 |& 84 | 45 x 15 SAO REY iti, 16 ih ae 17 SOL AED A AUG ey, We eee Rema Te Seg 18 SOD le ZOU ES ie kl, Le in| PORES. 19 20. 20 20k 20 epee hh Cones Chicks Pipping aH 20 20 724) 20 S545) oe All through hatching 22) Hee es -- | -50-_| 9 The volume of air given in these tables are the num- ber of cubic centimeters of incubator air which it took to cloud one cubic centimeter of lime water. (The first distinct clouding is the point used in the _ tables.) These are exact measurements and should be used in fut- ure investigations, to avoid the confusion of different standards. The figures for volume of carbonic acid gas are an arbitrary graphic representation of its density, as indicated on the piston rod of our air pump. They show relative, not actual values, but most admirably serve its purpose to show the difference between hen and incu- bator and different days of incubation. The actual amount of carbonic acid gas present in an incubator, it should be remembered, is also directly de- pendent upon the number of fertile eggs in a given en- closed space. These tables are not to be used for the purpose of guiding ventilation, in the sense of admitting air into the incubator in case there should be found more gas than our tables show. Keep your incubator closed tightly, no matter how much carbonic gas is found in it. We, ourselves, have not been able to obtain any higher values, and are of the opinion if we could secure 21 a machine giving higher values, it would be still better, for as will be seen from the tables giving the records of hens, that the amount of carbonic acid gas is much greater there. It will also be seen that the amount of gas under the hens is quite variable, depending upon how closely the hen is setting. We take it, that these investigations, prove, not act- ually how much gas is necessary to hatch eggs, but that absolutely confined air is of the very first importance in an incubator. If you confine the air in your incubator there will always be more or less carbonic acid gas present. On these measurements human breath shows clouding at about 20 to 25 cubic centimeters, or 25 volumes of gas on the figures for carbonic acid gas. It is noticeable also that even the chicks two days old under the hen’s wing, live in the presence of much car- bonic acid gas. Notice also that these hens bringing off perfect hatches only left the nest five or six times altogether. In cool- ing eggs this fact should be taken into consideration. A Be © SQ co ~~ & IG R |) rd oe a (a — 3. P. Cook’s Carbonic Acid Gas Test. Price, $5.00. a, graduated piston rod (for each fifty cc.) b, air pump; c, rubber tube; d, glasstube; e, five ce graduate; f, limewater. Ze METHOD FOR TESTING CARBONIC ACID GAS. Our method consists in withdrawing a certain portion of air within the incubator taken directly above the eggs, and about twelve inches from the front of the machine. A small hole is bored through the frame of the door about one quarter inch in diameter, through which a small rubber tube with a glass end is introduced. This rubber tube is attached to an air pump, holding from 250 to 300 cubic centimeters of air. The piston of the pump is graduated for each 50 cubic centimeters. After the air is withdrawn from the incubator, it is passed through one-half centimeter of lime water, and the point where the clouding of the lime water begins is noted. As is well known, this clouding is due to the amount of carbonic acid gas, which has passed through the lime water. The point at the piston is then read, which in- dicates directly how many cubic centimeters of air have passed through the lime water to effect the clouding. The piston rod is graduated up-side-down, beginning with 10 and ending with one, so as to indicate directly the amount of carbonic acid gas. For instance, if the first fifty cubic centimeters of air effect the clouding of the one-half cubic centimeter of lime water, the piston rod will stand at 10, which we designate as 10 volumes of carbonic acid gas present in the incubator. This is, of course, wholly arbitrary, but it serves very well to give an indication of the relative amount of the carbonic acid gas present. What this measurement actually amounts to is this: The fifty cubic centimeters of incubator air contains enough car- bonic acid gas to cloud one-half cubic centimeters of lime water, which is equal to 100 cubic centimeters of incubator air clouding one cubic centimeter of lime water. We suggest that all incubator tests on carbonic acid gas to be made in the future, be made upon this measure- ment, as it is very convenient indeed, and serves all prac- tical purposes in the best possible way. Some unit of measure will have to be decided upon, and as all our tests have been made on this, it would only confuse mat- ters if any additional standard of measurements were in- troduced. The lime water which we use is prepared in the ordin- ary way, just taking a piece of unslaked lime and dissolv- ing as much of it in water as the water will take up per- fectly clear, and using the clear part of the water. We use the ordinary five cubic centimeter graduate. The whole outfit is sold for $5.00 to anyone who is interested in these experiments. It is necessary to clean the graduate after each test, as more or less clouding will be effected, which will interfere with the reading. If an ordinary rag will not clean it, use a drop of hydrochloric acid, which will clean the graduate in- stantly, and it should be well rinsed after cleansing. In all our tests the air was not withdrawn from the incubator until it had been closed for 24 hours. 23 THE MOISTURE PROBLEM. There is no end to the theories about moisture in an incubator. There seems to be an almost universal opin- ion that eggs will be helped by being sprinkled, or by filling the incubator by some means with moisture. Undoubtedly the moisture problem is a very important one in artificial incubation, and it is by far the most difficult of solution. It is comparatively easy to deter- mine the relative amount of carbonic acid gas under a setting hen, and it is also comparatively easy to secure something of a corresponding amount of this gas in an incubator by reducing the air space surrounding the eggs, but with the moisture problem it is different. It is al- most impossible to find out the relative amount of mois- ture surrounding the eggs under a setting hen. The space is so very small that it is almost impossible to make any test. The wet bulb thermometer is practically inap- plicable here. The amount of moisture introduced by the wet bulb would interfere with any correct results of a test. About the only other method available is the use of the spiral hygrometers, which are very unreliable at best. We have made hundreds of tests of setting hens, using a spiral hygrometer, placing it as carefully as possible, and after reading it transferring it to an incubator, and intro- ducing moisture into the compartment, or withdrawing it until we found a corresponding reading, and then compar- ing it with our wet bulb instrument. There would be only one other way of measuring the moisture under the setting hen, and that would be by withdrawing a small portion of air, and by analysis de- termining the actual percentage of moisture present in it. For this we did not possess the necessary instru- ments, and it is very doubtful if it would be of very much value. The results which we have obtained have been variable indeed, ranging as low as 35% of humidity, and as high as 60%. It has been impossible to get almost any two readings alike. Perhaps the only actual result that is dependable is the fact that in all cases the hu- midity of the air surrounding the eggs under the hen was considerably drier than the outside air. It was also found that the amount of humidity under the hen bears no corresponding relation to the humidity in the outside air. Some of our tests of hens setting practically out of doors, in rainy weather, with the rain dropping over their wings, still showed only about 40° of humidity over the eggs. But to repeat, none of the tests made can be regarded as in any sense absolutely accurate, so we have no clue as far as the hen is con- cerned, what the amount of moisture should be sur- rounding the eggs. Perhaps the safest way is to re- gard the lowest reading the most accurate, as nearly all instruments register higher than actual humidity. When it comes to the incubator it is easy enough to determine the relative humidity inside the egg chamber. All that is needed is a reliable wet bulb thermometer. 24 Place it carefully, and read the difference between the dry thermometer, and the wet bulb thermometer, and the amount of relative humidity can be readily determined by the use of psychro-metrical tables published by the United States weather bureau. (A number of so called incubator hygrometers are on the market, which pretend to give a direct reading of the humidity in the egg cham- ber, but these cannot be used for anything like accurate work. Some of them do not read low enough, and it is doubtful if others are sufficiently accurate. Any hygro- meter that does not read as low as 385° is worthless for incubator use, and should not be sold for that purpose.) For all practical purposes it is much simpler to disre- gard the actual relative humidity, but carefully note the depression of the wet bulb thermometer. In that way all confusion and difficulty is avoided. The only method open to determine the right amount of moisture for successful incubation, is by repeated ex- periments. Our experiments in this line have continued for over six years, and hundreds of hatches have been carefully noted. We have never found a good hatch unless the air in the incubator was comparatively dry. The percentage of about 40° or 45° humidity seems to give the best results, which is equal to a depression of about 18° to 20° on the wet bulb thermometer. Where it is possible we prefer to use 20° of depression for hatching, i. e., 88° on the wet bulb. We have had uni- formly good results at this point, provided all other things are right. There is no doubt that a great many incubators, and a great many hatches fail because it is impossible to get the air dry enough. Of course, on the other hand many hatches are spoiled by the air being too dry on account of the excessive ventilation within the incubator chamber. But it was found in our other ex- periments that there must be practically no ventilation of any kind in the incubator chamber, and the air surround- ing the eggs must remain perfectly quiet in order to main- tain sufficient carbonic acid gas and prevent the formation of cripples. This makes the moisture problem a most difficult one. Incubators will act as contrary as anything that can be imagined in this respect. The problem in incubation is to get the air within the egg chamber to run about 83°, wet bulb, without ventila- tion of any sort. Where this cannot be accomplished the hatch will be more or less a failure. Some incubators we have had we simply could not use at all. Others of identically the same make worked without any trouble. Only a very few that we found needed artificial moisture, when the machine had been made practically air tight. One of our large machines was a constant puzzle to us. It contained eight compartments holding 2000 eggs. The compartments are all built identically alike. They are all heated in the same manner by one hot water sys- tem. They all show the same temperature yet one com- partment runs 20% higher in moisture than all the others, and consequently we cannot use that compartment. We 25 have been unable to determine any reason whatever for this difference. There are certain seasons of the year, however, when all the compartments run alike, and we can use the whole machine. This is simply one of the instances of the many queer actions with which incu- bators confront us. We find that a space about twelve inches high from the bottom of the machine to the top is necessary to give suffi- cient dryness of the air, which has to take up of course the evaporation of the moisture from the egg, and still not become too highly saturated with moisture. We have sometimes found it quite an improvement to slip a diaphragm, made of thin muslin, between the eggs, and the hot water pipes, thus making two compartments in the machine. The diaphragm should be close to the pipes. Small openings may then be made through the top of the machine into this upper compartment, say one or more half inch holes for every 250 eggs. This has a tendency to cause a very, very slow movement of the air, and as more heat is needed to heat up the incubator through this diaphragm, there is more dry air in the ma- chine than can otherwise be secured. It seems the small opening helps to dry out the air without appreciably af- fecting the air below the diaphragm. In smaller machines we have found a rather effective way in allowing hot air to circulate around the heater, and allowing it to open into the upper compartment of the machine. This makes the circulation of the air much slower since it has no outlet, but it seems to secure the dry atmosphere, which is so very essential in the egg chamber. The moisture in the air of the incubator room has no effect on the eggs in the machine. An incubator with ventilators open will usually register much drier on blus- tering rainy days than on hot, dry, or sultry days. In warm weather the incubator ventilators do not work at any rate, for if there is not much difference in the tem- perature outside the machine, no air will pass through. It may be given as a safe rule never to put water in an incubator, on hot sultry days. If ever any moisture is needed, it is in winter, or on windy days. Those are the times when the incubator is actually too dry. This will sound strange, to the inexperienced, but place a re- liable hygrometer in the incubator on hot, dry days, and you will find a very high humidity. The opposite will be found on cold days, even if they are rainy. More air is sucked through the incubator on cold, windy and blustering days, which causes it to be excessively dry. Sprinkling the floor of the incubator room has not the slightest effect on the moisture within the machine. The effect of too much moisture in the incubator will be that many chicks are dead in the shell, as many as one half or more sometimes. A rough distinction may be made in this way: If the chicks that hatch are scrawny little things with protrud- ing entrails, or unabsorbed yolk, there was too much ven- 26 tilation. If the chicks that hatch are fairly good and large in size, the chicks dying in the shells is due to too much moisture. Both faults cause chicks to die in the shell, and both must be avoided. However, it is safe to say ten times as many chicks die in the shells from too high humidity, i. e., too much moisture, than for lack of it. If moisture is actually needed, the best way to intro- duce it is a wet sponge placed on the eggs. Water pans may be placed in the bottom, but this does not usually have much effect. A Dry Ther moOmelév B. Wet- Bulb Poychrometer C Water-Cistern ; 1 P. Cook’s continuous reading Hygrometer.Price, $3.00. Zee Cooks simplified Hygrometer. Price, $1.00. DIRECTIONS FOR USING P. COOK’S HYGROMETER. Our hygrometer consists of two accurate thermometers, one of which has a muslin wick connected with a water cistern, attached to it. The whole instrument is placed in the machine like an ordinary thermometer. The evap- oration of water from the wick around the bulb of one thermometer causes this bulb to cool in proportion to the amount of evaporation. The drier the air in the incu- bator, the more rapidly will it evaporate water from the wick and thus cause the wet bulb to read lower than the dry bulb thermometer. Indirectly, the difference be- tween the two thermometers indicates the dryness of the air. This is the method used in the U. S. Weather Bu- reau, and it has published elaborate tables from which say the relative per cent of humidity can be learned if once the depression of the wet bulb thermometer is known. We print here a part of these tables as far as they are of use for incubator purposes. For instance, if the dry bulb stands at 103 and the wet bulb at 83, there is twenty degrees difference, i. e., there is twenty degrees depres- sion on the wet bulb. The wet bulb thermometer is technically called a psychrometer. From the table it will be seen that there is 42 per cent relative humidity in this case. Orif the dry bulb registers 100 degrees and the Psychrometer 82 degrees, there is 18 degrees depres- sion, and it is found from the table that in this case there is 46 per cent humidity. PSYCHROMETER TABLES. Degrees of Depression of Psychrometer 16 | 17 18 19 | 20 | 21 22 | 98 50 | 48 | 45 | 43 | 40 | 38 100 39 102 52 | 49 | 47 | 45 | 42 | 40 | 38 Aupraney aAnojay 52 | 49 | 47 | 45 | 42 | 40 | 38 a4 50 | 48 46 | 43 | 41 | 39 53151149] 461 44| 42 | 40 For practical purposes it is much easier, however, to disregard these moisture percentages. It is enough to know that when your thermometer reads 103 degrees and the Psychrometer 83 to 85, your machine is working properly and no further attention need be paid to it. Ordinarily, if an incubator is once started right, and our other instructions for closing the ventilators, etc., have been followed, there will be no need to use a hygro- meter, as the moisture does not generally vary much dur- ing a hatch. Nevertheless, it will soon pay to be in possession of a hygrometer, but as our larger instrument costs three dollars, it is too costly for the man who has only a small machine. We have, therefore, designed a much cheaper instrument, which is just as reliable, but takes a little more trouble to use it. This is simply an accurate Thermometer reading down to 75 degrees. A thin piece of muslin is tied around the bulb, this is dipped in luke-warm water and then inserted into the incubator, through a hole bored in the door. It is left there for ten minutes and then partly pulled out to see how low it reads. Its lowest reading, just before the muslin is completely dried out is its correct reading. A number of readings should be taken, the lowest one is the most correct. The incubator should not be opened be- 28 fore inserting the Psychrometer. Remember the differ- ence between it and your thermometer indicates the mois- ture. If your incubator stands at only 100 degrees, then 80 degrees on the Psychrometer indicates proper hatch- ing humidity. It is twenty degrees difference that is required. Use your table unless your incubator stands at 103 degrees. The simplified instrument is sold for $1.00, and will be found a most excellent help. Only one instrument is needed no matter how many incubators are used, as moisture does not need to be taken oftener than in the beginning and two or three times during the hatch. We are aware that these directions require much drier air thany many manufacturers advise, but we have in- quired among many hatchers and we have not heard of one of them that has succeeded in securing good hatches at any other percentages the great claims of some hygrometer makers notwithstanding. It should be remem- bered however, that our figures are for incubators with perfectly still air, i. e., without any ventilation. Still air is not nearly as drying as air in motion. From our standard hatching table it will be seen that during the exclusion of the chicks we allow 92 on the Psychrometer. This is normal and need not be changed unless chicks are breathing heavily or standing with their mouths open, This indicates too much moisture, as often as too much heat. Ventilators must then be opened, or if the machine has no ventilators, open the doors for a minute and let the moisture escape. As soon as the hatch is over, see that enough air is admitted into the machine to dry out and fluff up the chicks properly. Sprinkling the eggs will never do them any good; its only effect is to chill them, and if they hatch at all, they hatch in spite of it. In fact nothing that is done to the eggs for a few minutes during the last week, helps them in any way. We seldom ever find any need of moisture during hatching time, only if something is seriously wrong with the incubator moisture will help to over- come its defects. Shut your machine tight until pipping time, and do not open it till chicks begin to show signs of the need of more air. Some Typical Tests of Moisture Under Setting Hen. 7 a. m. Outside air near hen’s nest temperature 52 degrees, moisture full saturation or 100 per cent, moisture under the hen, 49 per cent. 12, noon, temperature out- side, 74 degrees; moisture 58 per cent; moisture under the hen, 40 percent. 5 p.m. Temperature 66, moisture 61 per cent. Moisture under the hen 40 per cent. In all the numerous tests we have made, we always found much less moisture under the hen than in the air around her. As she heats the air in her nest, it would naturally reg- ister drier than the outside air, unless she supplied mois- ture from her body, but as all tests show this is not the he) case. The hen does not sweat through her skin and it seems that her feathers asbsorb the evaporation from the eggs. We had one White Rock hen sitting on damp ground and the moisture under her always ran between 60 to 65 per cent, but all the germs rotted in the shell, only three lived till the 21st day, but did not hatch. The other tests above given are from hens that brought off normal hatches. Where we made daily tests for moisture, the hens al- ways brought off poor hatches, due no doubt to disturb- ing the hens too much. HELPING CHICKS OUT OF THE SHELL. There is little use to help chicks out of the shell when they have not been properly incubated, but in the moult- ing season we have sometimes found that the stragglers can be helped to advantage. A chick should never be helped too early, and unless it is plump and in every re- spect perfect when helped out, it is not worth anything In the time that eggs are naturally fertile, all chicks will usually pop out without any help. Chicks too weak to get out then is a sure indication of faulty incubation. No chicks should be helped out until the hatch is nearly over. TYPICAL WEIGHTS OF A GOOD HATCH. 100 Fresh eggs, 11% lbs. 100 clear eggs 10 ibs., 6 oz. (15 days in incubator), at 85 Psychrometer reading.) 100 chicks 8 lbs., 1 oz. GOOD HATCHES ATTRIBUTED TO WRONG CAUSES. Here it is well to point out that frequently good hatches are attributed to wrong causes. Mr. ‘‘A’’ puts a pan of water under his eggs, the last few days, or sprinkles them or gives more ventilation, etc., and has a good hatch. He concludes this is the thing to do. But it may have had nothing whatever to do with the good hatch. The fact is that strong eggs hatch well in spite of a good many things. We dropped a tray of eggs once. Two-thirds of the eggs cracked. (16th day of incuba- tion.) We patched them up with celloidin and they all produced remarkably strong chicks. Nevertheless, cracking eggs is not the best way to hatch them. It should be remembered, the critical period of incubation are the first six days, and it may almost be said, that it does not matter what happens after that. Certainly eggs will stand quite a lot of abuse after that and still hatch well. So far as ventilation is concerned, it may be said that most arrangements do not work, which is their recommendation. If the ventilators of the incu- bator actually get to work, then they produce mischief. If the incubator is placed in a room where the air is still, there is but very little ventilation going on inside the machine, but if the air of the room gets in motion, 30 it will be sucked through the ventilators of the incubator, and a spoiled hatch will follow. Too much ventilation produces small, scrawny chicks with protruding bowels, etc. A spoiled hatch from too much ventilation is about the sickliest sight imaginable. The glowing claims of incubator manufacturers that their machines change the air ever so often, are fortunately not often true, but when they are true their machines fail to hatch. It is not known whether the amount of carbonic acid gas has anything to do directly with hatching, for it varies greatly under different hens. It may be that all that is required is absolutely still air in the incubator. In still air the gases do not diffuse very readily. We found in one machine that had eggs only on one tray, twice as much carbonic acid gas as on the other tray without eggs. As a rule, there is a little more at the bottom than near the top of the machine, which is natural, since the carbonic acid gas is heavier than air. The fact remains, however, that eggs under the hen are incubated under the pressure of a very large amount of carbonic acid gas. This was found true even of a tiny bantam hen that weighed only about one pound, but the percentage of carbonic acid gas under her was as great as under the large hens. This proves conclusively, that there is no so-called ventilation under the hen, nor any diffusion of the natural gases, or the carbonic acid gas would have been carried away. The chief value of these measurements, as we regard it, is in the fact that they pointed out the right way to build an incubator, i. e., one that surrounds the eggs with still air, and thus produces conditions similar to those under the hen. There is, of course, no reason to believe that carbonic acid gas itself helps the hatching. Itis a waste product of the respiration of the embryo but em- bryonic respiration is a decidedly different process from respiration of the full grown hen, and a large amount of carbonic acid gas may not be detrimental, or it may have a sort of symbiotic action, but such consideration we may leave to the professional biologist. Ordinarily the user of the incubator need not test the carbonic acid gas. Let him follow our directions in con- structing his machine, and he will not generally experi- ence trouble. However, the carbonic acid test is the only reliable guide to the ventilation. METHOD OF HATCHING IN P. COOK’S MAMMOTH HATCHERY. (The method here given has reference to incubators sold commonly to the public, as this will be of great use to persons who already possess incubators. The prin- ciple is exactly the same as that followed in Mr. Cook’s own mammoth machines.) The first thing that is done is to see that the incubator is in good working order, the lamp burning properly and lamp fountain not leaking and thermostat in perfect 31 order. Then the door is examined, and if it does not fit air-tight, strips of felt are nailed around the edges, so as to make it fit tight. One or two layers of burlap or cotton batting are placed in the bottom of the ma- chine to make it warm enough below the eggs. The temperature at the bottom of the incubator should never be allowed to fall much below 90 degrees. If it is colder than that cripples are sure to result. If the machine has nursery drawers, it is best to fill these up with straw or cotton for the first two weeks at least. If the machine has no nursery the temperature at the bot- tom of the egg-tray should be at least 100 degrees. When the machine is heated up, the thermometer is placed in position where the top of the eggs would come and the regulator adjusted to hold the machine at 103 degrees. The machine is kept going for a day or so with ventilators open in order to dry it out. Then a hygro- meter is also placed into it and watched till it sinks to 83 degrees. It may take several days to dry out the ma- chine sufficiently. Then the ventilators are all closed and the hygrometer read again. If it stands between 80 and 83 degrees, it is all right. If it stands above that, the machine must be further dried out. There is not much probability of a good hatch if the hygrometer at the beginning of a hatch remains as high as 87 for more than a day. We had to run one machine for three weeks, before it became dry enough for hatching. If you cannot make your machine dry enough do not waste your eggs on it. We have never come across a machine too dry, if all its ventilators are closed. Next the egg trays are taken and fitted with a me- chanical turning rack as described elsewhere. The eggs are placed on the tray with the turning rack in position. They are laid flat on the side and not crowded. You can get more eggs into the machine by standing them on edge, or even by doubling them up, and the strong eggs will hatch that way, but the weaker ones will die in the shell. But remember, what is not good for the weaker eggs, is no benefit to the stronger ones either. Do not begin the poultry business by abusing your chicks before they are born. It is knocking your profits with a club on the head. When the eggs are on the tray, thermometer and hygro- meter are then placed in position and all outgoing venti- lators are shut tightly. The best way to do this is to stuff a tuft of cotton into the holes. It need not be stuffed very tightly. Those machines that have the air intake over the lamp or around the heater, need only to have the outlets closed, for as soon as these are closed no more air passes through them into the machine. On other machines all ventilators must be closea. The eggs are turned by the mechanical turner after six hours and after that every twelve hours apart, but under no conditions must the machine be opened for the first 72 to 84 hours. 32 On the morning of the fourth day the incubator is opened for the first time and the eggs are taken out and aired for about ten minutes. They are also tested for infertiles at this same time. Then the eggs are re- turned to the incubator and turned mechanically twelve hours after this without opening the machine. At the next twelve hours the eggs are aired again for ten minutes and so on till the twelfth day. After that they are aired 15 minutes, but never under any circumstances is the machine opened more than once a day. This method, ventilators closed, eggs aired only once a day, but turned twice daily, and 88 degrees on the psychrometer, we have found an unfailing cure for chicks dying in the shell. But no one of these details must be omitted, or the hatch may be spoiled. On the 18th day the machine is closed, but small ven- tilators may be left open, if your incubator room is free from drafts. There will be no trouble, if these directions have been followed, with chicks getting out of the shell. There will be a downy lot of fine fluffy balls, as lively as can be wished in your machine next morning. In one respect nothing is so important as this closing of the ventilators, especially if your incubator stands in a room that has the least draft in it. Eggs will not hatch to the best advantage except in absolutely still air. For that reason taking eggs out of an incubator twice a day is detrimental. Only the strong eggs will stand it, the weaker ones will die in the shell. Do not worry ‘ about the need of fresh air. There is tar more oxygen in the incubator than the eggs will ever need, as is shown conclusively by the carbonic acid gas test. It is true the carbonic acid gas may be a very variable quantity, de- pending upon the number of eggs in the incubator, ete., but the still air is the thing of highest importance. We know of hundreds of incubators that miserably failed to hatch with the manufacturer’s fresh air directions which became first-class hatchers by simply nailing up the ven- tilators and using a mechanical turning tray. During the proper season of the year we find that gen- erally every germ alive at the 17th day hatches a perfect chick. Even in the molting period we have had many perfect hatches by this method, but occasionally some chicks die in the shell then, however, we seldom find over ten per cent of dead chicks even at that time. Of course no account is taken of germs that die before the seven- teenth day. Sometimes there are many of these, but the fault lies with the eggs in such cases and neither hen nor incubator could hatch them. HATCHABLE EGGS. There is a large difference of opinion as to which is to be considered a fertile egg. Breeders in selling eggs usually follow the practice of guaranteeing a certain percentage of fertile eggs, meaning that they will replace any perfectly clear eggs below their guarantee. There are, however, always a certain number of eggs with im- 215) perfect germs or weak germs, or whatever they may be called. None of these imperfect germs can be expected to hatch. Neither hen nor incubator could do anything with them. Some of these germs do not develop any farther than simply to make a bloody streak through the yolk of the egg. Others grow longer. Some live as long as the 13th and 14th day. In all these cases the germ of the egg has been faulty, and it is impossible to hatch such eggs. The proportion of these eggs depends upon the vigor of the fowls, and to some extent also on the season of the year. It is a good plan to test all the eggs in an incubator on the 17th day. All of the em- bryos dead at that time should be removed. If all the chicks alive in the shell on the 17th day hatch, the hatch may be called a perfect hatch, as that is all that can pos- sibly be expected to hatch. But the great great difficulty with incubators has been that the chicks die in the shell after the 17th day. If any large proportion of chicks die in the shell after the 17th day we consider it the fault of the incubators, not of the eggs. After chicks have been developed up to that stage they would probably hatch if they had been incubated right. Our experience has been that if everything has been right during the period of incubation practically all the chicks alive at the end of the 17th day will hatch. MAMMOTH AND COMPARTMEN'T MACHINES. We have spent a great deal of money in the attempt to build a large compartment machine heated by only one heater and capable of continuous hatening. Such a machine is evidently very desirable for a large hatch- ing plant, but we have met with only moderate success in this direction. It is easy enough to construct a ma- chine with any number of compartments to hatch prop- erly if the entire machine is filled with eggs at the same time. Then all the compartments require the same amount of heat and the entire machine can easily be regulated by one thermostat. But difficulty arises when eggs of different periods of incubation are placed in dif- ferent compartments. The eggs much ahead generate a good deal of their own heat and have to be in cooler compartments. It is very difficult to remove surplus heat from such compartments without interfering with the necessary moisture and carbonic acid gas conditions. The easiest way to remove heat from a compartment would be by letting it escape through ventilators, but this is not permissable, for ventilation spoils the hatch. Stop cocks or other methods must be used, which involve a great deal of expense. It can no doubt be done, but we have abandoned it for our own use. We have found it much the cheaper method to build different incu- bators. One machine can be used for the first week, an- other for the second and a special machine can be built for the last week with conveniences to take care of the chicks for hatching. 34 j | | Our machines are 22 feet long and four feet wide and in this size we have found no need for more than one thermostat for each machine. Each machine is built with eight compartments independent of each other. NURSERIES. We have used machines with nurseries in nearly all our experiments. We do not know of how much real ad- vantage they are. In a big hatch chicks seem to have a lit- tle more elbow room as they are away from the shells. Many machines are made with drawers, but these are not always an advantage. If a machine is made with drawers, it should be so made that the egg tray is placed on the drawer and always comes out with it. If the drawers are made to slide in under the tray, there is always trouble. As soon as the drawer is pulled out a number of chicks will jump over the back of the drawer and others raise their head and you can neither shut nor open the machine or get the chicks. We prefer no draw- ers at all unless the egg tray comes out with the drawer. DISINFECTING INCUBATOR. At least every third hatch an incubator should be thoroughly disinfected. The trays and bottom should be thoroughly cleansed. They can be washed with almost any good disinfecting fluid or sulphur may be burned in it. This last is the most effective method, but it will require some days of airing before you can get the sulphur out again. However, it is not necessary to get all the sulphur smell out. We have had good hatches with the sulphur smelling strongly all during the incubation. The incubator is a splendid hatcher of all kinds of germs and white diarrhea may be caught in the incubator. On the other hand, the incubator should not be blamed for chicks dying after they are some days old. If the chicks are big and strong when hatched, you may be as- sured that the incubator has done its part. After that the fault lies with the brooding. INCUBATOR HOUSES AND CELLARS. Incubator may be placed in any room that will shel- ter it, but a basement or cellar that is light and cheery, and not too damp is very desirable, for the temperature of such a place is not subject to as much variation as an ordinary room. The most desirable temperature for an incubator room is between sixty and seventy degrees. The most important item, however, is, that it be well venti- lated, but absolutely free from draft. Nothing works so much mischief in an incubator room as drafts. In a perfectly quiet room it is not always necessary to resort to the mechanical turning tray. Eggs will fairly well 35 FES 14 1914 stand opening the machine twice a day for turning, only for the one turning the eggs must be returned as soon as possible to the machine. But even in the best incubator room a strict adherence to our method will be found to pay well. A cellar three feet deep with cement floor and walls and the rest of the building above ground, is the ideal for an incubator house. It should be kept dry. Never sprinkle the floor. It is immaterial whether lamps, gas or coal, ete., is used for heating incubators, but the fumes should be carried off through chimneys. CHICKS DYING IN BROODER. It is not always easy to raise a big flock of chicks artifi- cially, and while it does not belong here, we may as well point out one great means of saving chicks. People have become so accustomed to the necessity of disinfection that they believe if they could only kill all the germs, their chicks would do well, but they forget that there are as many if not more, beneficial germs as there are disease germs. Disinfection kills both the good and bad germs. The real remedy is not always more disinfec- tion, but better natural conditions for the chick. Prof. Metchnikoff, head of the Pasteur Institute in Paris hatched and tried to rear chicks under absolutely germ- proof conditions, but found that his chicks would dwindle away and die in a few weeks. Afterwards he allowed his chicks to come into contact freely with the ordi- nary dunghill bacteria and they were thriving as they should. The intestinal canal is inhabited by a number of bacteria that aid materially in digestion, and the en- tire absence of these causes many chicks to die appar- ently without any cause. One of our neighbors, a famous breeder of Barred Rocks, has for years claimed that the only sure way to prevent white diarrhea in chicks is to feed them a liberal supply of maggots. He has been a steady customer for the rotten eggs from our hatchery. He exposes them to the flies for a day and then lightly buries them. Shortly there is as big a lot of wrigglers as any old hen would want. He feeds these maggots regularly, and certainly raises magnificent birds on them. It is probably safest to use maggots thus produced under ground, for if the eggs were not buried, there might be ptomaines de- veloped. In everything the poultryman should remember that he cannot far transgress nature with immunity. If chicks are once well hatched, then look to your brooding system. 36 é Le My ‘ll Successful Incubation By P. COOK PtiStae gt” oo ee Cee | S pas hue’ 2 aie é Ain Pi hw Oy er kasi The WEIMAR PRESS, Los Angeles, Cal. LIBRARY OF CONGRESS 002 857