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The results of measurements of deep ocean currents over the continental slope off Sydney in May 1979 are presented and discussed. The measurements were made using neutrally buoyant floats. Four floats were used, at mean depths of 766, 1251, 1519 and 1886 m. All four floats moved towards north-north-east, approximately parallel to the depth contours, with mean speeds, over the 34-day tracking period, in the range 5-9 cm s-1. The surface current, estimated from ship's set, was towards north-east, at 25 cm s-1.

Pressed disks made from powdered crystalline long-chain n-primary and secondary alcohols have been shown to be electrically anisotropic. At a particular frequency, the loss factor, when the applied field is parallel to the faces of the disk, is from two to five times greater than when the field is perpendicular to the faces. The observed anisotropy is considered to be due to orientation of the flat crystals of the alcohols parallel to the disk faces. The effect of anisotropy on previously published results for long-chain compounds is discussed. The observed anisotropy is consistent with the main conclusions from this earlier work. The application of the measuring technique to other materials is suggested.

The dielectric loss factors of a number of heterogeneous mixtures have been measured 'at frequencies up to 3 Mc/s. The mixtures consisted of a non-polar base material and small percentages of a slightly conducting solid or liquid "impurity".

A previous publication described some electrical properties of crystalline n-primary alcohols of 16 to 26 carbon atoms. The present paper deals with an extension of the work to the lower homologues down to n-octyl alcohol, and includes the results of measurements on both the liquid and crystalline materials. To enable their more extensive investigation, the frequency range of measurement has been extended down to 10-4 c/s. by the use of D.C. methods.The alcohols of the present series resemble the higher homologues in giving two regions of dielectric absorption which overlap to an increasing extent with decreasing molecular weight. The absorption region at lower frequencies merges with the loss due to D.C. conductivity, the latter being much larger than for other long-chain compounds so far investigated.A feature of the results is the variation in the electrical properties of different samples of the same alcohol. This may be due to variations in the relative proportions of α- and β- crystalline modifications present in different samples.The results suggest that the absorption and the D.C. conductivity both depend on the presence in the crystals of hydrogen-bond chains. The high frequency absorption appears to be related to that in secondary alcohols and is probably associated with reversal of the hydrogen-bond chains by cooperative rotation of the hydroxyl group about the C-O bonds. The latter mechanism, together with proton transition, could lead to migration of the protons, and this may account for the D.C. conductivity. The absorption at low frequencies is attributed to a Maxwell-Wagner type of mechanism resulting from the situation of the conducting hydrogen-bond chains in a non-conducting matrix.

The intensity of ocean circulation off east Australia was found to be about five times that off west Australia, as measured by the variances of surface dynamic height, after allowing for latitudinal trend. A dominant horizontal scale length of about 500 km was found off both coasts, from structure functions of surface dynamic height. The structure functions are shown for the range 25 < l < 1200 km, where I = horizontal spacing between stations. In this range, the structure functions do not fit a 2/3 power law.

The variations in mean sea-level observed at Australian tide-recording stations during the International Geophysical Year are presented in graphical form and compared with the changes in density of sea-water measured near some of the stations. The observations are in general but not detailed agreement with the isostatic hypothesis according to which sea-level and water density are directly related.

Dynamic topographies and geostrophic currents in the upper 1750 m are presented for several cruises between 1960 and 1963. The mean zonal surface circulation is shown to consist of the south equatorial current, 9-14� S., and a weak easterly current between 14� and 32� C. From 0� to 9�S., and again from 32� to 45�S., the mean dynamic height anomalies are independent of latitude, so that mean geostrophic zonal currents are negligible in these latitudes. Changes in dynamic height of the surface relative to 300 decibars within 2-4 weeks are shown for five "seasonal biological cruises" , along 110� E. The significance of these changes in interpreting the dynamics of the region is discussed. Cyclonic and anticyclonic eddies appear occasionally off Fremantle, but no seasonal pattern was found. Cyclonic eddies south of Java are postulated, mainly during the south-east monsoon. A bathythermograph section across the equator on 95� E. is included; it shows no evidence of the equatorial undercurrent.

The along-track components of current for 55 southward passages between Cape Moreton (27�02'S.) and Sugarloaf Pt (32� 27'S.) on the east Australian coast have been analysed. The currents are predominantly towards the south, but their variability is stressed. At any particular time, departures from the mean current show appreciable correlation for distances up to about 100 km. At a particular latitude, departures from the mean current are positively correlated for time differences up to 20 days, and show a slight negative correlation for time differences of the order of 30 or 40 days, indicating a weak periodicity with periods of the order of 70 days. The connection between these and other estimates of space and time scales for the east Australian current is discussed. No evidence of alongshore movement of current patterns was found.

Temperature profiles to 250 m, obtained by using a bathythermograph, are presented and discussed in relation to geostrophic currents in the East Australian Current Area. There is a very close relation between dynamic height and temperature at 240 m depth in this area. Regression equations connecting the two quantities are given. The depth of the mixed layer is shown to cover a wide range, even on a single cruise in a relatively small area, and it is suggested that the extremes of very shallow (< 20 m) and very deep (≥ 200 m) mixed layers are due to divergence and convergence associated with the strong and variable circulation in the area. Seasonal warming and cooling affect approximately the upper 70-100 m, and have a range of about 3�C.