Measurements are described of galactic radiation at frequencies of 1210 and 3000 Mc/s. The results provide extensions of previous radio emission spectra by more than 2� octaves. The intensity of radiation from near the galactic centre was measured and an estimate made of the direction of the maximum of such radiation. A new " discrete source " of peculiar spectrum was discovered very close to the centre of the Galaxy. Evidence suggests that the power output of this and some other sources in the radio spectrum may exceed the total power output of the Sun. Radiation was also observed from the direction of the Crab Nebula, from the known " radio source " in Centaurus, and from the Moon. Two nebulae (M 31 and NGC 7293) were investigated with negative results. The spectra of two sources are given between the limits 18.3 and 1200 Mc/s.

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Measurements have been made of the thermal radiation from the moon in a 15 Mc/s. band, centred a t 24,000 Mc/s. The radiation from the whole lunar disk has been measured during several phase cycles. Temperatures corresponding to this radiation have been deduced and curves of temperature against phase angle drawn. One of these corresponds to average temperature over the disk and the other to the temperature of a point on the lunar equator. They are found to be approximately sinusoidal, with amplitude k 4 0 . 3 OK, and f 52.0 O K . respectively and with a phase lag behind the lunar phase angle of about 45' in each case.These results conflict with previous measurements of temperature a t long infra-red wavelengths in both amplitude and phase angle of the temperature curve. An explanation is given in terms of radiation from subsurface layers of the moon's crust, which are partially transparent to the electromagnetic waves with which we are dealing. The theory is developed quantitatively and it is found that the results are consistent with the existence of a thin layer of dust covering a solid lunar surface.Estimates are made of the temperatures of the disk of the new moon (I56 O K . ) and of the deep interior (241 OK.).

Observations are described of the radiation from portion of the constellation of Cygnus at frequencies of 1210 and 3000 Mc/s. Two sources of radiation were observed at the lower frequency, one being the well-known "radio star ", Cygnus-A. The other was a diffuse source of limited extent which might be called a " radio nebula ". Neither source could be observed at the higher frequency. The properties of both sources, particularly their spectra, are discussed and it is shown that earlier discrepancies in observations of the Cygnus region may be explained. The diffuse source coincides in position with the secondary maximum in the lower frequency galactic contours, which Bolton and Westfold (1950a, 1950b) have interpreted as a spiral arm of the Galaxy. The new evidence suggests that the source is probably due to thermal emission from clouds of ionized interstellar gas, possibly in the region of γ Cygni and having a temperature and electron density of the order of 104 �K, and 10 cm-3 respectively.

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