  The fourteen kinds of pressure-transmitting media were evaluated by the ruby
fluorescence method at room temperature, 77 K using the diamond anvil cell
(DAC) up to 10 GPa in order to find appropriate media for use in low
temperature physics. The investigated media are a 1:1 mixture by volume of
Fluorinert FC-70 and FC-77, Daphne 7373 and 7474, NaCl, silicon oil
(polydimethylsiloxane), Vaseline, 2-propanol, glycerin, a 1:1 mixture by volume
of $n$-pentane and isopentane, a 4:1 mixture by volume of methanol and ethanol,
petroleum ether, nitrogen, argon and helium. The nonhydrostaticity of the
pressure is discussed from the viewpoint of the broadening effect of the ruby
$R_1$ fluorescence line. The $R_1$ line basically broadens above the
liquid-solid transition pressure at room temperature. However, the
nonhydrostatic effects do constantly develop in all the media from the
low-pressure region at low temperature. The relative strength of the
nonhydrostatic effects in the media at the low temperature region is discussed.
The broadening effect of the ruby $R_1$ line in the nitrogen, argon and helium
media are significantly small at 77 K, suggesting that the media are more
appropriate for cryogenic experiments under high pressure up to 10 GPa with the
DAC. The availability of the three media was also confirmed at 4.2 K.
