Om Materialprøvningens Udvikling i Norden
Og om Statsprøveanstaltens Virksomhed

 162 s; in the first is placed the named knife-edge of the lever bearing against the edge-pillow of the frame, in the second the knife- edge which transfers the pressure to the pipe and in the third a bolt furnished above with a center-mark for the applying of the scale with the weight. It has namely been considered ap- propriate not to suspend the scale on a knife-edge but to use a suspension shown on a somewhat larger scale at p. 70 in fig. 26 and 27. In the steel-plate s is an oblong hole in which the bolt b can be displaced in the longitudinal direction of the lever and then be fastened, so that it is possible to attain that the pro- portions remains continually 1:10 even if the length of the wooden beam should be somewhat changed in drying up or swelling. In the bolt head b is the center-mark where the taper of the link B is applied. In the link the scale is suspended as shown in fig. 25 and 27. The loading is made by means of weights or by pouring water into a bucket placed on the scale. With this apparatus can be tested pipes where the outward diameter is up to 32" (84 cm). As indicated at p. 69 in fig. 25 the pipe is during the test placed on a block O of pieces of beams and planks placed on the concrete foundation K. The pressure is transferred to the pipe through a piece of beam Q to the top of which is screwed a piece of iron-plate where the knife-edge can touch. Between the block and the pipe as well as between the piece of beam Q and the pipe is placed a piece of felt of a thickness of about 15 mm in order to spread the pressure as evenly as possible over the whole length of the pipe. During the test the pipe is placed in such a way that the whole length except the socket is exposed to pressure. As results of crushing-tests with clay- and cement-pipes, as far as the knowledge of the Laboratory goes, have only been published from few quarters, the Laboratory will here give all results obtained until the 1st of July 1909. In the Table VII below is given the result of the crushing- tests with all clay-pipes tested up to the 1st of July 1909. In Table VIII occurs the result of Ihe crushing-tests made with cement- pipes up to the same date. The sign { means that two or more pipes of the same dimensions were sent in and tested at the same time.