Om Materialprøvningens Udvikling i Norden
Og om Statsprøveanstaltens Virksomhed

174 The drying power was determined in determining the point of time when the colour laid on had attained constant weight, it being assumed, that this was a rather good measure for the r e- 1 a t i v e drying power of the colours, while from a practical point of view this manner of proceeding could of course not say anything of their absolute drying power. The constant weight was reached after from 1 to 18 days and nights, Antiferugin being 18 days and nights in reaching this weight. The exposure to heating to 150—160° Centigrade took place in an oven during 2X6 hours, and after the heating various ben- ding tests were made partly with totally sharp bending, partly around bars of different diameters, and for comparison the same bending tests were made with painted iron-plates which had not been heated, and it was noted down whether the layer of colour parted or not from the various bendings or mouldered. As to the exposure to gaseous hydrochloric acid, the paint of white-lead and white enamel-colour on iron plates proved to be quite destroyed already after the lapse of 4 hours while the other colours were able to stand the influence of many hours, up to 20 hours, gone through by Antiferugin. It would be too long to render an account of the results of the many various experiments here. It is only to be specially quoted that the series of experiments 13 on resistance to wear were made in letting sand whose grains had a fixed size fall from a fixed height on painted circular iron plates of a diameter of 10 cm. The experiments were made with the apparatus shown at p. 83 in fig. 29. A is a funnel suspended by the string b pas- sing across the pulleys a and the funnel carries two horizontal arms c and c: at right angles to each other (the latter only visible as a point on the figure) and supplied with eyes through which the strings b and K pass. Arms and strings shall prevent the fun- nel from swinging to and fro. The taphole of the funnel can be shut by means of the stopper d which can be pulled out easily and quickly by means of the string fastened there. Perpendicularly below A is placed the apparatus B to intercept the sand falling from A. In B is a horizontal circular disc f sup- ported on 3 props and of the same diameter as the painted plates employed. C is a reservoir for the collecting of the sand. The experiment was made in the following way: After the tap-hole had been shut with the stopper d, the funnel was filled with about