METALLURGY. 



435 



shavings may be consolidated into a bar or cylin- 

 der, weighing nearly as much as a cast or rolled 

 bar of the same metal. It has been found easy to 

 solidify 'Pittsburg brass, which is reputed one of 

 the most difficult metals to unite by mechanical 

 pressure. 



An electric welding machine, designed by W. 

 Clark, is intended to be alike suitable for furnace, 

 crucible, open-hearth work, welding, brazing, and 

 hand soldering, etc. It is arranged so that the car- 

 bon holders are capable of movement in every 

 direction, admitting of their being placed at any 

 angle in any plane. In order to achieve this, the 

 framework supporting them consists of a slotted 

 arch of metal cast in two halves, which are 

 mounted upon a fire-resisting and insulated base, 

 and are efficiently insulated from each other at the 

 top, where they are bolted together. The carbon 

 holders have a swivel action, fitted with thumb- 

 screws, so that they may be clamped in any posi- 

 tion. The swivel action is attached to an insulated 

 bolt, which passes through the slots in the 

 framework, and allows of adjustment to any height. 

 Each carbon holder having an action independent 

 and insulated from the other and from the frame- 

 work, it is readily seen that they are easily capable 

 of any arrangement to suit requirements. 



In a successful test of a new welding machine 

 the Debombourg at Bucyrus, Ohio, the iron was 

 heated for a butt weld of 3-inch round bars. When 

 put into the machine the bars were immediately 

 gripped and by the use of a side lever squeezed into 

 each other. The operation took only three min- 

 utes. When put up to the breaking test the weld 

 was found to be the strongest part of the bar. It 

 also withstood a severe tensile strain. The machine 

 is simple, weighs only 1,300 pounds, and is capable 

 of handling bars from 1 inch to 6 inches in diame- 

 ter. No hammering is required to complete the 

 weld. 



Miscellaneous. In a lecture at the Royal Insti- 

 tution on "The Metals used by the Great Nations of 

 Antiquity," Prof. J. H. Gladstone began by speaking 

 of some small gold and copper objects that were 

 found in the recently discovered tomb of Menes, 

 the first of the Pharaohs of Egypt, whose date is es- 

 timated to have been about 4400 B. c. The use of 

 copper for tools was illustrated from the recent 

 discoveries of Prof. Petrie and others in explora- 

 tions at Negada. Later methods of hardening this 

 copper by hammering or by the admixture of ar- 

 senic or of tin in sufficient quantities to form 

 bronze were elucidated by experiments and the re- 

 sults of analysis. Lead, silver, and antimony were 

 introduced at dates which have not been fully de- 

 termined ; and the lecturer believed that iron was 

 little used, if at all, in Egypt before 1200 B. c. In 

 Assyria, the earliest specimens of metal had been 

 found at Tello. They consisted of copper and sil- 

 ver, and were thought to date from about 2700 B. c. 

 The accounts of the great quantities of gold and 

 other metals stored up in treasure houses or paid in 

 tribute in the time of the great Babylonian empire 

 were illustrated from the drawings on the black 

 obelisk of Shalmaneser II, and the bronze gates of 

 his palace. In Palestine the Hittites used gold and 

 silver for commercial and ornamental purposes ; 

 and the various peoples found in that land by the 

 Israelites on their return from Egypt also employed 

 bronze and iron. Copper implements of war had 

 been found at Tel-el-Hesy, the ancient Lachish, in 

 the Amorite town, and in the Jewish town, with 

 bronze vessels, occasionally silver and lead, gradu- 

 ally giving way to iron. The excavations by Dr. 

 Scliliemann and others at Tiryns, Mycenae, the 

 supposed Troy, and other places, proved the abun- 

 dant use of gold and copper by the Archaic Greeks, 





and the successive introduction of bronze and iron 

 before the compilation of the ' Iliad." 



The American section of a proposed international 

 association for testing materials has been organized 

 at Philadelphia, with Prof. Mansfield Merrimann as 

 chairman. Among the various problems to be 

 submitted to it are : Ways and means for establish- 

 ing international standard specifications for the in- 

 spection of all kinds of iron and steel on the basis 

 of those already existing; determination of meth- 

 ods of tests of the homogeneity of iron and steel, 

 looking to their eventual use in inspection ; prepa- 

 ration of uniform methods of test of paints as pro- 

 tection against corrosion of railroad structures; 

 unification of tests of terra-cotta pipes ; investiga- 

 tion of behavior of iron under abnormally low tem- 

 peratures ; methods of testing welds and weldabil- 

 ity ; collection of all information for preparation of 

 standards for piece tests, with special reference to 

 axles, tires, car springs, cast and wrought pipes, as 

 well as of separate parts of structures ; investigation 

 of the most practicable methods of polishing and 

 etching for micrographic study of wrought iron. 



Concerning the "fatigue of metals," which is 

 sometimes cited to account for failure of forgings 

 of iron and steel, Mr. F. H. J. Porter says that 

 while our knowledge on the subject is still limited, 

 it is known that the metals being initially crystal- 

 line, do not become so from shock or any similar 

 service when cold. " Fatigue " simply means that 

 frequent repetitions of load in amount far below 

 the ultimate strength of the material will eventu- 

 ally break down its resistance and cause failure. 

 Beyond the bare statement of this fact, laws of a 

 general character have been formulated, but the 

 complex nature of the situation prohibits exactness. 

 No two pieces of metal are alike in chemical com- 

 position ; and, if they closely approach similarity in 

 this respect, the difference in mechanical treatment 

 in their manufacture causes them to possess widely 

 different physical properties. Generally speaking, 

 we know that for any given stress a certain number 

 of repetitions produce failure ; the greater the in- 

 tensity of stress, the smaller the number of repeti- 

 tions. We know also that the stress required lo 

 cause failure is less, and, roughly speaking, only 

 half as great when the metal is strained alternately 

 in opposite directions as when it is strained in one 

 direction only. It is very striking how regularly 

 progressive is the increase in the number of repeti- 

 tions, as the range of stress decreases ; and if we 

 can make the range of stress small enough, a prac- 

 tically unlimited number of repetitions is required 

 to cause failure. From certain tests that have 

 been made it has been found that within a certain 

 limit, which is approximately one half of the ulti- 

 mate, strength, the metal is elastic, and if strained 

 beyond this point its working strength is exceeded, 

 and it can no longer be depended, upon to sustain 

 even minor loads. Such tests give results, however, 

 which -.are siniply relative. Their actual signifi- 

 cance is uncertain. The fact that a metal possesses 

 a certain elastic limit, elongation, and contraction 

 of area when ruptured by once loading, fails to 

 convey an adequate idea of what the same metal 

 will do under circumstances of repeated stresses or 

 when these stresses are applied in alternate direc- 

 tions, as they are in practice. 



The surfusion of metals and alloys is their main- 

 tenance in a fluid state at temperatures which are 

 many degrees below their true freezing points. It 

 has been shown by Ostwald that a very minute 

 quantity of a solid will cause a mass of the same 

 substance to pass from the surfused to the solid 

 state. The same author distinguishes between the 

 mefa-stable, or ordinary condition in which surfu- 

 sion takes place, and the labile condition which 



