Om Materialprøvningens Udvikling i Norden
Og om Statsprøveanstaltens Virksomhed

126 cent, and in 1 pipe both strength and elongation were too small, namely respectively 31,5 and 11,7. For steam pipes bending tests were made with the same 8 deli- veries, but only with altogether 34 pipes. Of these only 1 did not stand the test, but broke in two athwart, namely the pipe where the elongation of the material was but 9 per cent. As to gas- and conduit-pipes tensile tests were made with 5 deliveries, the test being made with altogether 33 pipes Among these 33 pipes the test proved unsatisfactory for 6 pipes. In 3 of these pipes the strength was too slight, namely respec- tively 30,0, 31,3 and 31,2 to 32,0 instead of at least 33 kg pr. sq. mm, in 3 others the elongation was too small namely 10,3, 11,8 and 6,8 to 7,9 instead of at least 12 per cent. By the pipe with a tensile strength of 30 kg pr. sq. mm. the elongation could not be measured, the fracture falling outside the gauge length. For gas- and conduit-pipes bending tests were made with the same 5 deliveries, but only with 31 pipes. Of these 2 did not go through the test, the one broke in two athwart, namely that one whose tensile strength was 30 kg pr. sq. mm, by the other the weld opened in no small degree. At the Congress in Copenhagen Mr. Karsten, chief-engineer in the municipality of Copenhagen, will read a paper upon testing of pipes of malleable iron and render a detailed account of the results of the tests dealt with here. On testing wire-rop.es, the wires of the rope are usually uncoiled and an alloy cast round. As it appears from p.24, fig. 7, the socket where the casting takes place is on the middle of the under side turned so as to form a spherical face resting during the ten- sile test against a corresponding depression, so that a central clas- ping is obtained by the thus produced spherical movement. For impact test on cycle-front-forks the Laboratory has constructed the apparatus shown in fig. 8 at p. 25. The front-forks steering column is fixed so that the fork- sheaths G project horizontally and are loaded at the extreme end, as it appears from the figure, by the attaching of a weight P of 93 kg. whereupon the current to an electro-magnet E is interrup- ted, so that the anchor A hanging below and weighing 2,16 kg, falls down on P through a height of about 18 centimetres. By means of the test it is examined whether the forks are da- maged, the Laboratory having decided upon a certain deforma-