August 23, 1889.] 



SCIENCE. 



127 



per annum, or very nearly $3,000,000 for each day in the year. 

 The regular expenditure of more than 90 per cent of this vast sum 

 stimulates other industries, and in this manner the volume of gen- 

 eral business is increased in progressive ratio. 



In these calculations no account has been taken of the large 

 number of people forming the proprietary interest of this vast ag- 

 gregation of capital, which comprises people in all classes and in 

 all occupations, and scattered throughout all parts of the country. 



The New York Central Railroad Company has 10,000 stock- 

 holders, whose average holding is about $9,000. If we take that 

 sum as representing the average holding of all stock and bond- 

 holders in the country, the total number of such would be over 

 1,000,000, representing more than 5,000,000 persons with important 

 interests in the success of the railroad system. 



From these deductions a general idea can be gathered of the 

 magnitude of the railroad interest, and how vast and widespread is 

 the interest of our people in that system. 



From the tables in the iVIanual it appears that during the past 

 ten years the following percentages of profit have been distributed 

 to holders of the share capital of our railroads. In 1879 the divi- 

 dends paid averaged 2.5 per cent of the total amount of capital 

 stock outstanding ; in 1880, 2.8 per cent was paid; in 1881, 2.9 

 percent; in 1882, 2.91 percent; in 1883, 2.75 per csnt ; in 1884, 

 2.48 per cent; in 1885,2.02 per cent; in 1886, 2.04 per cent; in 

 1887, 2.18 per cent ; and in 1888, 1.77 per cent. 



in the essential oil which renders them so destructive to insect life. 

 Like many other products, insect powders are liable to adultera- 

 tion, and last year a large quantity made from the flowers of th'fe 

 Hungarian daisy, mixed with a small proportion of pyrethrum, was 

 placed upon the market by unscrupulous dealers. Inferior pow- 

 ders are also manufactured from the stems and leaves of the plant, 

 which possess, to a certain extent, the properties of buhach. 



BUHACH. 



In an article on the California insecticide known as buhach, 

 which was mentioned in Science of May 24, the Jotcrnal of the So- 

 ciety of Arts, London, says this product is a fine powder made 

 from the flowers of the Pyrethrum citieraricefoliwn, largely used 

 for the destruction of insects. This plant was originally a native of 

 Persia, from whence it was introduced to Dalmatia and adjoining 

 States of Herzegovina and Montenegro, where it has been almost 

 exclusively cultivated until a few years ago. The importance of 

 this industry was considered so great in these countries that spe- 

 cial efforts were made to prevent the export of seeds and plants by 

 the governments. The plant was first introduced into CMifornia 

 about twelve years ago by a Mr. Mileo, a native of Dalmatia, who 

 succeeded, after some trouble, in obtaining seed from his country. 

 After experimenting for some time, in order to find a suitable soil 

 and climate, this gentleman finally succeeded in growing the plant 

 on an extensive scale, and in 1880, associating himself with other 

 ■capitalists, established the Buhach Producing and Manufacturing 

 Company. At the present time the company have about 300 acres 

 of this plant under cultivation at their farm near Atwater, Cal., and 

 own mills for grinding the dried flowers to powder at Stockton. 

 The cultivation of pyrethrum requires careful and intelligent su- 

 pervision, and it cannot be grown successfully without irrigation. 

 It requires three years from the time of sowing to grow plants ca- 

 pable of producing a paying crop of flowers, and then they will 

 bear from four to five years longer. It is at its prime, however, in 

 its fourth or fifth year. The plant grows about thirty inches high, 

 and is set out in rows four feet apart, and from fifteen to twenty- 

 four inches apart in the rows. The flowers are harvested towards 

 the latter part of May. The stalks are cut just above the roots, 

 and the flowers stripped from them by passing the plants through 

 a kind of comb. The detached flowers fall into a box below, and 

 are carried to the drying ground, where they are spread on sheets 

 and exposed to the rays of the sun during the day, being repeatedly 

 turned over in the meantime. They are covered during the night to 

 prevent their absorbing moisture, as the perfect drying of the flowers 

 is most important in order to retain the volatile oil which gives the 

 powder its insecticide properties. It is also very necessary that this 

 operation should be done quickly, and that the flowers during the 

 drying process should be protected from moisture. A slight dew fall- 

 ing upon the flosvers at this time will injure their color, and reduce 

 their strength as an insect destroyer. In this respect the Califor- 

 nia-grown flowers are better cured, and, consequently, more valua- 

 ble than those produced in Dalmatia, it being acknowledged by 

 experts that the particular conditions of soil and climate in Califor- 

 nia are extremely favorable to the growth and curing of plants rich 



SAWING STONE BY HELICOIDAL WIRE CORD. 



A NEW plan of cutting stone by means of wire cord has been 

 adopted in many European quarries. While retaining sand as the 

 cutting agent, M. Panlin Gay, of Marseilles, has succeeded in ap- 

 plying it by mechanical means, and as continuously as the sand 

 blast and band-saw, with both of which appliances his system — 

 that of the " helicoidal wire cord " — has considerable analogy. 



An engine puts in motion a continuous wire cord (varying from 

 five to seven thirty-seconds of an inch in diameter, according to 

 the work), composed of three mild steel wires twisted at a certain 

 pitch, that found to give the best results in practice, at a speed of 

 from fifteen to seventeen feet per second, the higher speed being 

 adopted for the, smaller diameter. 



Instead of the stone being brought to the saw, the wire cord, 

 which may be of indefinite length, is led to the stone, being guided 

 by grooved pulleys, mounted on bearings with universal joint, 

 which permits of their adapting themselves to any change of direc- 

 tion. The same cord, which is kept at uniform tension by a 

 weighted truck on an inclined plane, may act upon any number of 

 blocks, provided sufficient space be given between them to allow 

 for cooling. 



The pulleys are mounted in standards, and are fed down by end- 

 less screws rotated automatically if the stone be uniform, but 

 preferably by hand if there is reason to suspect irregularities in its 

 texture. Sand and water is allowed to flow freely into the cuts, the 

 sand carried along by the cord in the spiral interstices between the 

 wires causing a uniform attrition of the stone. The twist of the 

 cord causes it, while travelling, to turn upon itself, and thus be- 

 come worn evenly. A cord of 150 yards in length will cut about 

 seventy feet deep in blocks fifteen feet long, or produce four hun- 

 dred and ninety square feet of sawn surface before being worn 

 out. 



The sand must be sharp, and not used more than three times. 

 The nature of the sand is determined by the hardness of the stone ; 

 thus, quartz sand will cut granite and porphyry, which it has hith- 

 erto been found impossible to saw, or indeed cut in any other way 

 than by pick or chisel. An hourly advance of one inch in gran- 

 ite or porphyry and four inches in marble, is regularly obtained in 

 blocks of fifteen or sixteen feet long. At the Brussels Exhibition of 

 last year, where the system was awarded a prize, the same cord 

 which cut marble also cut a block of concrete composed of quartz 

 pebbles. 



Not merely does the helicoidal cord saw blocks of stone, but it 

 even cuts them out of the solid rock in the quarry. To do this, it 

 is necessary to sink shafts of two or two and a half feet in diame- 

 ter, in order to introduce the pulley-carriers. If there is a free side 

 to start from one shaft is sufficient for a triangular block ; but for a 

 quadrangular one, which is preferable, two shafts are necessary. 

 They are bored by a mechanical perforator, consisting of a hollow 

 plate-iron cylinder, having at its lower end a slightly thicker collar 

 which acts with sand and water in its latest development. The 

 cylinder is made to revolve, at a speed of one hundred and forty 

 revolutions a minute, by means of a tele-dynamic cable, advancing 

 about an inch per hour in marble. An annular space is cut in the 

 rock, leaving a core, which may be utilized as a column. The di- 

 ameter of the shaftway depends upon the diameter of columns 

 most in demand, provided a sufficient number be sunk, and the in- 

 tervening angles broken down, so as to afford sufficient room for 

 the pulley carrier. 



In the case of stratified rocks, the shaft-cuts are carried down to 

 a natural parting ; but in unstratified rocks a nearly horizontal cut 

 may be piade with the cord, sufficient inclination being given to 

 insure the flow of sand and water to the bottom of the cut. 



Such is the method of working practised at the Traigneaux 



