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POPULAR SCIENCE NEWS. 



[August, 1S89. 



air entangled in tlieir meslies, which, being a 

 poor conductor of heat, adds considerably to 

 the warmth of clothing made from them. In 

 hot weather we wear light cotton or linen 

 clothing, so as to allow as much of the bodily 

 heat to escape as possible. There is a preju- 

 dice in favor of light-colored clothing for 

 summer wear, but it is hardly based on scien- 

 tific grounds. Dark-colored cloth is the best 

 radiator, allowing the bodily heat, to escape 

 freely, while white clothing absorbs less of 

 the heat radiated directly from the sun. 

 Therefore, to dress scientifically in summer, 

 one should wear dark clothing in the shade 

 and light clothing when exposed to the sun's 

 rays. Practically, the matter of appearance 

 is the only one to be considered, as the 

 warmth or coolness of clothing is not appre- 

 ciably affected by its color. 



TROUT CULTURE. 



A TROUT preserve requires a permanent supply of 

 pure, cold water, and a sufficient feeding ground, 

 where animal food — as aquatic insects, crawfish, 

 frogs, and such minute creatures as exist in running 

 streams — can be procured. Otherwise, these fish 

 must he fed upon such food as milk curds, waste 

 meat, and offal, finely chopped. Where a trout 

 stream can be diverted in part into a pond, or a suc- 

 cession of tliem, an excellent preserve can be made. 



Just now the eggs of these fish can be easily pro- 

 cured, either by purchase from dealers, or through 

 the fish commissioner at Washington, who is the 

 agent for the public, who support a very complete 

 establishment for this purpose. I have a fine trout 

 stream running through my land here, which is 

 doubtless the finest locality for this fish in North 

 America, as the climate is cool and equable the 

 whole year, and the copious rainfall (60 inches in 

 the year) provides a large supply of spring water, 

 containing an inexhaustible quantity of the best 

 kind of food. Being a popular pleasure and health 

 resort, a large number of visitors come here to enjoy 

 the fisliing and hunting, and were it not that the 

 streams are restocked by spawn gatliered at the 

 proper season, and hatched artificially in suitable 

 apparatus, the supply would soon be exhausted. 



The hatching trouglis are quite simple affairs. 

 For io,ooo eggs, a wooden box 14 inches wide, 12 

 inches deep, and 6 feet long is sufficient. Mine are 

 prepared as follows : The box, open on the top and 

 at one end, is divided by cross cleats, 3 inches wide, 

 set 16 inches apart in sections. A one-inch rustless 

 iron pipe brings pure, cold water from a spring into 

 the troughs, the water flowing through the box so 

 as to overflow the cross cleats and run off at the 

 lower end, or it may pass from trough to trough 

 through several of them. The sections are covered 

 one inch deep with coarse, cle.'ui-washed gravel, .ind 

 the water is filtered through a flannel .screen at the 

 upper end of the trough. Tlie lower end of the 

 trough is open, but covered with a wire gauze 

 strainer. The eggs are divided so as to put about 

 2,000 or 3,000 into each section, and are spread 

 carefully with a feather, to prevent them from lying 

 upon each other. Only pure water is used to flow 

 over the eggs, and freezing is to be avoided as fatal 

 to them. To prevent freezing, tlie troughs may be 

 gunk a few inches in the ground and covered by a 

 close shed, wliich need not be lighted. 



Tlie eggs, in a dormant condition, may now be 

 procured. Tliey are shipped by some rapid transit 

 in boxes with damp moss. As soon as they are 



received, they are carefully transferred into pans of 

 cold spring water, and the moss floated ofT without 

 handling tliem. When quite clean, they are gently 

 poured from the pan into the trough, and spread 

 with the feather over tlie gravel, so as to lie closely, 

 but not touch or overlie each other. They will 

 hatch in thirty to forty-five days, as the temperature 

 is warmer or cooler, when the tiny fish gets outside 

 of tjie egg, but still adheres to it, and it may be seen 

 swimming about with the egg still attached. The 

 young trout are supported by the egg, which is all 

 absorbed in covirse of time and disappears. When 

 this happens, they may be turhed into the stream to 

 take their cliances, or they may be fed for a few 

 weeks until they are larger and stronger. 



The food may be curd of milk rubbed up with 

 water into a thin paste, which is quickly diftused in 

 the running water of the trouglis ; or fresh liver or 

 lean meat, pounded or chopped into very fine parti- 

 cles. The small fragments of food are picked up 

 voraciously by the hungry infants, which grow very 

 fast, and when an inch long are quite capable of 

 taking care of themselves, along with other trout, 

 in a stream or pond where there is plenty of room 

 for them. They seek the shallow places, where 

 larger fish do not venture, and shoals of the tiny 

 things may be seen on the shallow, sandy banks. 

 By fall they will be three inches in length, after 

 which they will disappear in deeper water. 



Some kinds of trout grow with amazing rapidity. 

 Three years ago I put 100 California or rainbow 

 trout into a millpond on the stream mentioned, in 

 the fall; they were then "fingerlings," or three 

 inches in length. A year after, I took one eight 

 inches long, weighing half a pound. Last year 

 some were taken fourteen inches long and weighing 

 twenty ounces. The back is a deep puiplish black, 

 the belly silvery white, and the sides scarlet and 

 crimson in various shades, melting into other 

 colors. The flesh is as good as the best of the com- 

 mon speckled trout. The two species breed to- 

 gether, as I saw them last season pairing on the 

 spawning beds on the bright gravel in the clear 

 water, as I stood on the high bank of the stream. 

 What the cross will be, of course will not be seen 

 until a year or two to come. 



Trout may be preserved in a stream if the small 

 fish taken are always returned to the water without 

 serious injury. They seem to be but little hurt by 

 the hook if it is carefully removed. I have released 

 a small trout, hooked through the jaw or the nose, 

 and have taken it again the next cast. Fish are 

 cold-blooded and have a low nervous organization, 

 and do not sufler pain as warm-blooded animals do ; 

 hence, when released after having been caught, go 

 on their way without trouble. The loss of an eye 

 liy the hook is not any serious injury to them, and 

 if the small ones under six inches in length are 

 thrown back, the stock will .soon be visibly replen- 

 ished. I would like to impress this idea on those 

 interested in the stocking of streams, so as to pro- 

 cure a law to prevent the killing or sale of trout less 

 than six inches in length. I have t.aken trout no 

 longer than this that were full of eggs fully two 

 months before the spawning season, and on this 

 account the close seasoiT for this fish might be anti- 

 cipated by a full month earlier than it now is with 

 much advantage to the future supply. 



Trout will do well anywhere in streams which are 

 supplied by springs, and are never warmer than 80° 

 in the summer, and liave deep holes and sh.aded 

 banks and an outlet into a lake. They arc found in 

 the highest perfection in the northern states, espec- 

 ially where they can winter in large lakes, or can 

 rundown in the fall to deep pools and estuaries; 

 and especially in the southern mountain region, 

 where the clear, cold, pure water gives them the 



brilliant hues and firm fltsli which 1 have not seen 

 surpassed, excepting in the streams of Lake Supe- 

 rior. In ponds that are devoid of shaded banks, the 

 required protection from the sun m.ay be afforded by 

 large plank floats, moored to stakes, under wliich 

 they will gather at the heat of the day. 



In feeding fish, care is to be taken not to foul the 

 water with the refuse that is not eaten, and to give 

 no- more than will be consumed at one time. The 

 newly-hatched fish should be fed every two hours, 

 with a very little food at a time. And it is indispen- 

 sable that all sediment in the hatching troughs 

 should be prevented, or removed if any should get 

 in through the strainer; any dead eggs, which are 

 opaque and discolored, should also be removed.— 

 Henry Stewart, m Country Gentleman. 



GLEANINGS. 



Prevention is easier and cheaper than cure; 

 therefore keep your hogs and all other stock in 

 healthful quarters, and as far as possible away from 

 all rotting, decomposing matter, and from foul 

 water. 



Ancient Gardening Products. — Pliny men- 

 tions a variety of asparagus that grew in the gardens 

 at Ravenna, three heads of which weighed a pound. 

 Truly, there is notiiing new in the way of asparagus, 

 so far as size is concerned. 



Deae Animals. — Evidence exists that deaf mutes 

 are not confined to the human race. In a farmer's 

 herd for twelve years was a cow which never gave 

 any sign of hearing, and the evident attempts of 

 which at lowing had only resulted in a feeble gut- 

 tural. Nothing abnormal could be discovered in 

 the ears or the vocal organs. 



Variations in the Composition or Milk. — 

 From the results of about 50,000 analyses made in 

 the laboratory of the Danish Dairy Supply Com- 

 pany, it is found that the dry matter less fat is an 

 almost constant value (S.7 to S.S.) The fluctuations 

 in total solids depend almost entirely on variations 

 of the fat. The evening milk contains more fat and 

 more total solids than the morning milk. In Octo- 

 ber and November the milk is richer in fat and total 

 solids than in other parts of the year. 



Buckwheat, often called "the lazy man's crop," 

 deserves better treatment than it generally gets. It 

 is a "catch crop," easily grown between regular 

 succession crops, and will respond to more generous 

 usage than is frequently accorded it. The grain 

 itself is nutritive and palat.able, giving both heat 

 and muscle-making constituents, and brings, as a 

 rule, fairly- remunerative prices, compared with 

 other cereals. Manure with a liberal hand, or fer- 

 tilize with, say three hundred pounds of a good 

 superphosphate, and see the ditterence in the result, 

 compared with one grown on the thin, poor land to 

 which it is generally allotted. Sow from one to one 

 and a half pecks to the acre of seed. 



Losses and Gains of Nitrogen in the Soil. — 

 The results of the observations made at Grignoii 

 may be summed up as follows: All the plots con- 

 taining notable quantities of combined nitrogen (15 

 grains to the pound), and cultivated without 

 manure, have lost considerable proportions of nitro- 

 gen. These losses greatly exceed the demands of 

 tlie harvests. They are by no means equal for all 

 crops, being very rapid in soils which have been 

 planted with beets, rather slower for feeding maize, 

 and still slower for soils which have yielded pota- 

 toes and wheat. When, after several years of culti- 

 vation without manure, the soil has been Impover- 

 ished down to 1 1 to 12 grains of nitrogen to the 

 pound, the losses cea.sed and a gain in nitrogen set 

 in. This gain, trifling in soils under varied culti- 

 vation, has been considerable for grass-lands. 



