552 



PEHR OLSSON-SEFFER 



sand was dyed in colored water and then thoroughly dried. By 

 weighing the colored sand I satisfied myself that the weight had not 

 materially increased through this process. At the time the observa- 

 tions were made, this colored sand was laid out in ridges transverse or 

 parallel to the direction of the wind or in small heaps, the different 

 results being noted in each case. 



In order to ascertain the height to which different grades of sand 

 were lifted by the wind I devised a simple contrivance, which seemed 



Fig. 2. — Established dune destroyed by the wind. Near Southport, Queensland. 



to fill the purpose. Five sheets of corrugated iron held together by 

 a frame , were placed above each other at a distance of 2 cm. with the 

 lowest floor resting on the ground, and with the wrinkles at right 

 angles to the direction in which the sand moved. The front of each 

 sheet was flattened for about 12 cm., so as not to give any obstruction 

 to the wind or sand. These sharp, parallel edges divided the sand- 

 shower, and the grains were collected in the folds of the apparatus. 

 By closing the front and sweeping the different "floors" samples 

 for examination were secured. For the sake of brevity I have in the 

 following pages spoken of this apparatus as the "sand separator." 



