Skptembkr 14, 18S.!.] 



SCIENCE. 



377 



the seed for new Iwginners. The present expansion 

 of oyster-faruiing is due to the use of steam-power in 

 gathering tlie harvest. 



The lirst thing done on an oyster-farm is to stake 

 it out into sections, and then the bottom is ex- 

 amined. The next step is to scatter oyster shells 

 over the farm, and the oyster spawn is scattered. 

 After this, in some muddy localities, small trees, 

 mainly birch, are thrust into the water, in a standing 

 position; and the young oysters set on these trees. 

 The spawn is cast out from June until November, and 

 for a few days the ytmng oy>ters swim everywhere 

 they please, leading a happy life for a brief period. 

 Shelling begins about June 15, and ends about Aug. 

 15. When the oysters till the trees, the latter are 

 pulled up and cleaned off. From one acre of biishf s, 

 1,(KX) bushels of oysters have been gathered in one 

 year. .The oysters set on anything which is clean. 

 Tliey had been found on olil boots, old wrecks, and 

 a pair were found on an old padlock. Oyster-farm- 

 ing was not profitable every year: one firm having 

 lost $20,1)00 by the ravages of the star-fish in one bed, 

 and another firm $100,000 in two years from the same 

 cause. Oysters were formerly imported, but are now 

 exported in immense quantities. 



The Grerman Ceirp. and its introduction into the 

 United States. 



BY C. W. SMILEY OF WASHINGTON, D. C. 



The United States fish-commission, he said, had 

 some years ago imported from Germany thirty or 

 forty pairs of this fish. They were placed in breeding- 

 ponds in Washington, and have increased many-fold, 

 the number spawned this year being 400,000. The 

 carp is naturally a warm-water fish, and in the waters 

 of the southern states grows with astonishing rapid- 

 ity, and to great size. They will also do well in the 

 cold water of the north, even in Minnesota. Nearly 

 every state and county in the United .Slates has a 

 fish-commission, and they are all propagating carp. 

 It has also been taken up as a private speculation, 

 and' carp are sold for breeding-purposes as high as §5 

 per pair. 



The carp roots about in the mud for aliment, and 

 much resembles poultry in its manner of getting food. 

 Carp aged three years are often found to weigh twelve 

 to fifteen pounds, and a gain in weight of four pounds 

 has been observed in a carp in one year. The carp is 

 sluggish; while trout, bass, and other lively fish frisk 

 about, and do not fatten so fast as the carp. Experi- 

 ments have shown that female carp spawn at the age 

 of one year in southern waters, at two years in colder 

 waters, and in the extreme northern waters of the 

 United States at three years. Other fish, turtles, 

 muskrats, snakes, and even birds, eat young carp. A 

 bird shot in Washington recently had in its stoin.ach 

 the heads of seventy-uiue young carp. The U.S. fish- 

 commissioner recently sent out requests for informa- 

 tion about carp experimented with in this country; 

 most of the replies placing llie carp on an equality with 

 trout, bass, atid shad as a food fish, while a few chissed 

 them with pike, and a very few said they had a mud- 



dy taste. The carp is the best pond fish yet known, 

 and in a very small pond will thrive well, so that 

 families may easily have their own fish-garden if they 

 have enough water to make a permanent pond. The 

 carp is a'very hardy fish for shipment, requiring little 

 water to keep alive in. The U.S. fish-commissioner • 

 is giving away carp, sending them by express to .any 

 ]ioint, the receiver paying express charges. The fish 

 will thrive on table-refuse and almost any thing edi- 

 ble. Carp can be kept in winter in a tub in the 

 cellar, the water requiring to be kept fresh. Care 

 should be taken to l<ecp poisonous substances out of 

 carp-ponds, and too much food should not be thrown 

 in. In cooking carp, thorough cleansing is needed; 

 and frying should be done in hot pans and hot gre.ase. 

 As to the economics of this subject, Mr. .Smiley 

 said that fish-culture was more and more becoming a 

 part of the farmer's occupation, and thought that, not 

 very long in the future, most of the farmers of the 

 coimtry would have little fish-ponds in their door- 

 yards, both as a method of obtaining food and as an 

 ornament to the homestead. 



Cable-cars for city passenger trafiSc. 



BY E. T. COX OF >EW UAKMOXY, IND. 



Propes.«or Cox, though devoted to geology, has 

 always taken a kindly interest in schemes for indus- 

 trial advancement. In the present paper he describes 

 tlie success of the cable system as a substitute for 

 horse-cars; and urges ils general adoption, on the 

 ground of its convenience and comfort to humanity, 

 as well as the diminution of suffering to the horse. 

 Some of the collateral statistics presented in the paper 

 are interesting; e.g., the figures given by Mr. Moody 

 Merrill, cliairman of the horse-car railroad convention 

 held at Buston last March: '"There are in the United 

 States and Canada 415 street-railways, giving employ- 

 ment to about 8"),(M)0 men, 18.000 cars, and 100,000 

 liorses in daily use. These horses consume l.")0,000 

 tons of hay, and lll,0iK),OO0 bushels of grain. ;5.(KK) 

 miles of triick represent an invested capital of ><1.W,- 

 000,000. The number of passengers annually car- 

 ried is l,21-J,460,0tK). In the city of New York there 

 are 110 miles of horse-railway, and 11,806 Iiorses 

 are used to operate them. The horses, together with 

 their harness, expensive lands and stables, feed and 

 grains, make the oper.ating expenses, by including 

 interest, $5,104,000.79 per annum. The average life 

 of the street-car horse in New York is less than three 

 years." 



The paper quotes an opinion of Gen. W. Sewell 

 of New Jersey, a practical railroad engineer, who 

 prophesies that, within ten years, the cable system 

 w ill supersede horse-cars on every considerable street 

 line. The great advantage of the systom is its appli- 

 cability to very steep grades. The paper stales, in 

 respect to the most vital <|uestion to capitalists, that 

 the cost of the plant in the cable system is shown to 

 be about $70,000 i)er mile of roadway. We have 

 heard it recently stated, in other quarters, at §120,000; 

 but perh<aps one estimate apjilies to single and the 

 other to double tracks. This makes it, at best, some- 



