Incoherent scatter observations of E and F region drifts over Millstone Hill (42.6¿N) were made routinely from May 1976 to November 1977 at monthly intervals. Some 667 hours of data gathered over this 19-month period have been analyzed to yield the ionospheric polarization electric field in the magnetic south and magnetic east directions for three seasons during quiet magnetic conditions, as well as the annual average during magnetically disturbed conditions (Kp?30). The results for the quiet days are compared with earlier results obtained at Millsone Hill [Kirchhoff and Carpenter, 1976> and with those reported from St. Santin (44.6¿N) by Blanc and Amayenc [1979>. We find that there is best agreement between Millstone and St. Santin for the east-west component of the field which exhibits a roughly 12-hour period variation during the daytime in all seasons. The north-south field exhibits a predominantly diurnal variation that, in winter and equinox, is almost identically opposite at the two stations. This component shows substantial changes in summer at both stations and, at Millstone, appears to exhibit a significant (~1mV/m) average northward component not seen at St. Santin. We attribute the differences in the quiet time behavior observed at Millstone and St. Santin to the very large difference in the latitude of their conjugate points where, presumably, the tides (and hence the dynamo effects) are dissimilar. There are marked differences in the electric field patterns between disturbed and quiet times which mainly are evident in the nighttime period. Commencing after noon, there is a gradual enhancement of both the northward and eastward fields on disturbed days. The eastward field reverses near midnight and becomes westward until dawn, while the other component remains northward for most of the night. These changes are thought to result from the penetration of auroral electric fields inside the plasmasphere.