The age-herald., 1897-10-24
NOTES OF SCIENCE
 AND INDUSTRY.

known as the Beam process, Tn WHICH the furnace consists of a series of muf- fles, constructed of firebrick and tiling. The ore is first crushed to forty-mesh and then put in the muffies, from which the air has been excluded; the roasting is them begun and kept up until the chemical combustion takes place, when 1 the hot air, or oxygen, is introduced, 1 which changes the sulphides to sul- 1 phates, and thus saves the value The 1 time occupied by tine roast runs from one
 to three hours. and the cost as reported, l is less than 50 cents a ton. A low degree
 of heat-not more than 400 to 300 degrees 1 Fahrenheit-is required; and after the 1 roast the ore is pu'fverized to seventy l or eighty mesh, and is then treated by | pan amalgamation. The special advan- l tage presented by this method Is that while the ordinary fire assay does not 1 show the value of the ore, the Beam | process prevents loss by volatiization. The discovery of a secret solution by which leaden bullets may be coated so as to render them superior to steel-cased bullets, is announced by Charles W. Bales a chemist, and Edward Gerry, surveyor, of Springfield. H. The ordi- nary leaden bullets, when used in the | Krag- -Jorgensen rifle, have been found to be too soft, and the lead has clung to the barrel of the rife until the barrel was finally clogged, and the steel car trdgss which have succeeded the lead ones have eventually torn the barrel faults not found in the new article In pursuing their experiments these invent ors it appears, succeeded in procuring some of the smokeless powder used by the government in the Krag-Jorgersen rifles. making numerous tests with their cartridges, and with results showing the remarkable efficiency of the new and secret prepara ton. Thus. at distance of thirty yards, they bored a hole through an axe blade, and also through a fiat-iron; in this latter case the bullet lodged in a tree, entering a distance of six inches.
 Tn it's work of hydraulic dredging on l the lower Mississippi the Unit;d States. government uses a machine that sucks up sand and muck from the bc.tom of the strea m and discharges the material one thousand feet away. It can be op- erated up stream, or down stream, push ing with the cutters against the sand bar or dragging them backward. In the stern of the dredge are two "spuds" or piles, which are driven down into the river bed to act as pfvots, permitting the dlredge to swing in the arc of circle, sucking up all the sand which comes near the cutters, and, by swinging on one | of ,he spuds as a pivot, the dredge cam remove 800 cubic yards of bottom with out moving forward; 1t can move for ward at the rate of five and a half feet | a minute and suck up sand at the rate of 5000 cubic yards an hour, in a shont | time cutting channel the full width of the battery of cutters across sandbar. | This enormous sand sucksr is 172 feet | long and 40 feet wide, and weighs, with | its machinery, 200 tons. It carries ninety tons of coal and has water bal l last to equalize the draft. It has bat tery of four 375-ho.se power boilers, the runners of the centrifugal pumps being seven feet in dia meter. The engtns driv- dlng the pumps are triple eXpa nston, and are of the vertical, inverted, four cylinder tandem type.
 The calorific and evaporative value of various oils a fuels for steam raising has been made the subject of much in- vestigation by R. R. Wallis, of South Shields, England. In comparing coal ard oil he shows that the value of each variesS greatly with the quality and circum- stances under which! they afe burnsd. oil doing from one and half to two and a half times the work of an equal weight of coal. This is accounted for in various grounds, namely, the complete combus- ton of oil without loss of hea,. by soot or smola=; there are no fires to clean, with the accompanying loss of heat and revolution of the engines being main- tained; the boiler tubes are always clean and in the best condition, for the heaii from gases passing through them to the boiler; and, lastly, the temperature Of the escaping gases may be lower than is necessary to create the draught required for coal firing. T1l7n, too, there are no bars nor thick fire for, the air to force its way through; the required amount of air can be drawn through the furnace by a lower take temperature, ard the admission of air being under complete control and the fuel burned in fine parti- cles in close contact with the oxygen of the air, only "a very small excess of air is required.
 One of the few exclusively important imported British -prpducts used in our, country fs chalk. sIts comes from the.
 banks of the River Thames. being ob- tainaIble nowhere els, in large quanti-
 ties. In it's crude form, remarkable
 flint fossils are sometimes found, usually the remains of fish. The process of manufacture from the natural state to
 tha | of a form when 1t can be utilized
 is simple. ,., When received at the mill
 the cilalleli is put ~into great machin :; and ground in water, then fioated off into vats of water where all the impurities and foreigns su bstances are precipitated. the water being aftefward drawn off by series of Altering operations, and the soft reeiduum dried by steam heat and e.,prsure to the air; the subs ance IS then