OCR Text |
Show It sample size inhibited adequate vapor diffusion. For comparative purposes of testing chemical effects, the results are probably adequate. Control Samples Approximately two- thirds of the snow crystals present were replaced by depth hoar crystals 1- 2 mm in size. The characteristic fragility of depth hoar structure was moderately present. Crystals were commonly of the cup type, with a few 90° angles observed. Sample with 1,3~ dibroao~ 2- prQpanoli Depth hoart formation was somewhat more extensive than in the control sample. The normal cup crystals 1- 2 mm diameter predominated, but crystals with 90° angles were more common than in the control. Structure was typically fragile. Sample with methyl N- butyl ketones Some inhibiti © n of sublimation crystal forms apparently occurred. Those which did develop exhibited a pronounced tendency to form columns and 90° angles. The sample was mechanically firmer than the one with propanol, and fragility was roughly comparable to the control. Crystal size 1- 2 mm. Sample with 2- octanols A pronounced enhancement © f depth hoar development occurred in this sample. Conversion to sublimation forms was virtually complete. The crystals achieved lengths of 3 to 4 mm, larger than in all the other samples, but the most striking feature was the predominance of columnar crystals nearly to the exclusion of other forms. The gross crystal structure was very fragile, mechanically the weakest of the samples. |