Om Materialprøvningens Udvikling i Norden
Og om Statsprøveanstaltens Virksomhed

 ....... \ i w 161 through it. It must, however, be observed that the Laboratory has later changed its test of resistance to frost for sand-lime bricks — see under c — and intends possibly to introduce this changed test also for cement bricks. During the last year there has been required commenced by the Laboratory a longer series of experiments with producing of cement-bricks in different proportions while employing various sorts of cement and sand. The producing of the) bricks was made at different times of the year (also in order to substan- tiate the influence of the season on the strength of the bricks) at a cement-brick-manufactory in Jutland controlled by the La- boratory, while the compression-tests of the experimental series produced were made at the Laboratory at certain intervals. The experiments are still continued. e. Testing of Clay- and Cement-Pipes as to their Resistance to Pressure from without. The tests made by the Laboratory on this line and on which Report XIII1) was formerly published were with very few ex- ceptions executed after the method recommended by the Inter- i national Congress of Brussels in 1906 after proposal of Prof. Gary, the pressure having at these experiments been working along single generators, and only these experiments appear in the following tables. For these tests the Laboratory employs the Tinius Olsen- machine — see Report I — when the inward diameter of the pipes does not exceed 6" (16 cm); for pipes of this dimension there is still room here. The apparatus of the Laboratory for testing of pipes where the diameter exceeds 6" is a lever as shown at p. 69—70 by fig. 25—27. R — see p. 69 fig. 25 — is a frame of F -iron founded into ä very large concrete block K. The frame consists of 2 pieces of perpendicular jT-iron connected above by a short piece of horizontal Q-iron to which is se- cured by bolts an edge-pillow P. Aaginst this edge-pillow the lever V itself bears with its one knife-edge. The lever is a wooden beam into which are let 3 steel-plates 3) A summary of this report is to be found in Tonindustrie-Zeitung 1907, p. 1695.