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Harmonic analyses of weekly means of soil temperatures were made at Jodhpur, India with sandy to loamy sand soil (clay content 6–8%). The amplitudes and phase angles corresponding to various depths in respect of different harmonics are presented. The amplitudes for various depths vary between 4.8°C and 9.1°C for first harmonic and decrease sharply with higher order harmonics. The values for fourth harmonic range from 0.12–0.64°C only. The warmest soil near the soil surface occurs on June 28 while at 120 cm depth, the highest temperature maximum occurs on July 29, a delay of one month. Though many workers have reported that the annual soil temperature cycle is well represented by the first harmonic alone, it has not been found true under Jodhpur conditions mostly due to occurrence of the southwest monsoon is well reflected, if the third harmonic is superimposed on the sum compared to 96–98% reported by other workers. The second and third harmonics represent 8–22 and 0.6–4% of total variance respectively. This effect of monsoon period on soil temperature profile at Jodhpur is due to infiltration of rainfall. The change in soil temperature pattern after July due to occurrence of the southwest monsoon is well reflected, if the third harmonic is superimposed on the sum of the first two harmonics. The thermal diffusivity computed from amplitude variation and from phase displacement do not agree—showing the non-applicability of the theory of heat conduction in a semi-infinite homogeneous medium for Jodhpur soil. The mass movement of moisture during the monsoon and flow of moisture in the vapour phase probably invalidate the application of this simple theory.

Class A pan evaporation data are examined for 49 computation periods of 5 days at Jodhpur in the Indian arid zone. The 5-day periods cover the growing seasons of 1963 and 1964 for native vegetation. Multiple regression analyses were carried out of evaporation Y (mm day −1 ) against the climatological factors, total global radiation X 1 (cal. cm −2 day −1 ), estimated net radiation X 2 (cal. cm −2 day −1 ) saturation deficit at maximum temperature epoch X 3 (mm of Hg) and saturation deficit at mean temperature X 5 (mm of Hg) and mean daily wind speed X 4 (km h −1 ). The results indicate that the aerodynamic factors are important in the Jodhpur climate and the pair of factors, saturation deficit at a maximum temperature epoch and daily mean wind speed explain 83% of the variance. The addition of measured total global radiation or estimated net radiation increases the explained variance by 5% and 1%, respectively.

The cross sections for neutron absorption by N/sup 14/, O/sup 17/ and Ne/ sup 21/ are given for 10, 15, and 60 kev neutron energies, and the products of the abundances expected in stellar interiors and the capture cross sections for 15 kev neutrons are listed. At low temperatures in stellar irteriors the neutron capture process, starting with Ne/sup 20/ as seed nucleus, is discussed and seen to progress in a cycle through Ne/sup 21/, O/sup 18/, O/sup 19/, F/sup 19/, F/sup 20/, back to Ne/sup 2 0/. This cyclic reaction is seen to establish a definite dynamic equilibrium between the species of atomic nuclei involved in the cycle. Abundance ratios of Ne/sup 20//Ne/sup 21/ and O/sup 18//F/sup 19/ are calculated and compared with observed ratios. Some possible neutron and heavy seed nuclei production processes are discussed. (H.D.R.)

The tensor form of a viriai theorem for plasma is given, taking into account both electric and magnetic field effects. Only high-frequency behavior is considered, and dynamic effects of ions and collision effects are ignored. The virial theorem is obtained by applying a suitably defined electric-field potential tensor. (T.F.H.)