Abstract
The two-dimensional orientation of soil particles is easily treated if it is measured and analyzed by the vector method for sand and by the optical method for Clay. The arrangements of particles obtained by these two methods are not able to compare each other within the resolving power of optical microscope, and then model arrangements are investigated by studying the intensity of light transmitted through them for comparision of both methods.
A simple apparatus for measuring the intensity of light was set up in a polarizing microscope, and from the measurement of intensities of light passing through optically anisotropic particles and given an experimental equation is given from the difference of transmissions through parallel and crossed nicols. The model arrangements for that indicates the variation between two directions of particles are expressed by the ratio of minimum and maximum intensities of the above equation, on the basis of an assumption that the long axis of a particle coincides with the direction of oscillation of either ordinary or extraordinary ray in it. It is, however, not able to make a comparision of the arrangements between single particles given by the above two expressions, because the random arrangement defined by the ratio of intensities is different from the trigonometric one. For this reason, the application of some spatial distribution function is necessary to consider in relation to both methods.
