Om Materialprøvningens Udvikling i Norden
Og om Statsprøveanstaltens Virksomhed

tray where there was water up to a height of 2,5 cm, and at intervals of one hour it was observed how much the water rose in the bricks; the bricks were also weighed after 7 and 24 hours. The curves at fig. 20, p. 591) show graphically the average height which the water had attained in the 4 sorts of bricks. The facts stated here explain several hitherto obscure pheno- mena. Abiding by the above named experiments it becomes clear, for instance, why the C-bricks, clasped into straps, which were said to have neither frozen to pieces in nature or when tested in Berlin, displayed some disruptions of the shell and just on the header-side turning downwards, on being tested at our Labora- tory. This is namely explained in that the water, because the capillary attraction was not strong enough to keep it up, has sunk down to the bottom of the bricks, the lower parts of these thus becoming overfilled with water as compared with the upper parts. This becoming less apparent by the tests of resistance to frost in Berlin can bei explained in that the bricks in Berlin were clasped in a lying position and here standing up. It may be ob- jected that bricks tested by the older method of the Labora- tory also display disruptions of the shell on the header- side and lower bed these having not touched the bottom of the ice-case. Disruptions of the shell occurring nevertheless is due to the above named overfilling of the pores in the nether parts of the bricks. Hereby first one part of the lower bed and the header-side is damaged. Next time when the brick has come to lie on the other stretcher-side, the other part of header-side and lower bed is overfilled. Another fact, which might seem to speak against the impor- tance of the capillary attraction, is that appearing in those bricks which have been standing on a header-side, these also displaying some disruptions of the shell elsewhere than in the nether part of the brick. It must, however, be remembered here that the bricks may partly come in contact with the sides of the ice-case, partly with one another; this wil], of course, principally be the case, when the bricks have suffered so much on the header- sides turning downwards, that they are shaking to and fro. If clasped, no other disruptions of the shell would hardly have been observed than those in the nether parts of the brick (the corners excepted, see below). In the bricks clasped into straps disrup- J) In Fig. 20 the word »Timer« means hours.