XXX CONTENTS 



848. Interstellar gases (calcium, sodium) 644 



849. Temperature of interstellar space 645 



850. Matter and energy 645 



Compton effect 646 



DeBroglie phase waves 646 



Neutrons 647 



Positrons 647 



851. Packing fractions (Aston) 648 



852. Cosmic rays 649 



Appendix 



853. Area of ocean depths (Littlehales) 650 



854. Oceanic gradients (Kaummel) 650 



855. Atlantic Ocean basin. Areas and depths (Littlehales) 650 



856. Indian Ocean basin. Areas and depths (Littlehales) 650 



857. Pacific Ocean basin. Areas and depths (Littlehales) 651 



858. Physical properties of sea water (Thompson) 651 



859. Chemical composition of sea water (Thompson. Robinson) .... 652 



860. Waves of the sea (Patton, Manner) 653 



861. Properties of carboloy 654 



862. " Dekhotinsky cement 654 



863. " fused quartz (vitreous silica) 654 



864. " phenol-resinoid products 655 



865. High vacuum technique 655 



866. Relative viscosity of water ; high pressure variation 656 



867. Viscosity of mercury ; high pressure variation 656 



868. " some glasses at high temperature 656 



869. Some possible accuracies, 1928 656 



870. Properties of malleable cast iron 657 



871. Definitions of units 658 



Index 661 



