The path of an electromagentic wave propagated through the earth's atmosphere depends upon the homogeneity of the atmosphere. For the well mixed condition, which is the case most of the time, the wave follows a straight or a smoothly curved path. However, if the atmosphere is not homogeneous, the wave may change direction abruptly along the path. It is shown that a simple model can be used to represent the propagation path. The model is shown to consist of a beam from the transmitter to the reflection point and from the reflection point to the receiver plus a beam which travelled directly from the transmitter to the receiver. Under well mixed atmospheric conditions, the direct path is straight, while under anomalous atmospheric conditions the direct beam is allowed to follow various sized parabolic paths. The angle of arrival of ten centimeter microwaves, for a 32.5 mile marine path, was recorded for the period from August 19 to August 26, 1955. The model was found to fit the recorded data for approximately ninety per cent of the points considered. An examination of the meteorological conditions during the period indicates that high temperature and low wind velocity are conducive to abnormal propagation, but that no direct correlation can be made between angle of arrival and meteorological data.