xxii : Proceedings. 
which had never been published. The letter was referred to 
the Council. 
Prof. Pritchett read some notes by Profs. Holden and 
Barnard of the Lick Observatory, Hall of the Naval Observ- 
atory, Young of the Princeton Observatory and Swift of the 
Rochester Observatory on ‘* The Physical Observation of 
Mars During the Opposition of 1892.’ These papers gave 
in brief the results of physical studies of the planet during 
recent favorable opposition. The most interesting deduction 
from them is the magnitude of the changes going on upon 
the surface of the planet. It seems scarcely possible that 
these changes can be completely explained by terrestrial 
analogies. Thus in one montb an area of 1,600,000 square 
miles of snow had been converted into water. With the 
extensive oceans we have upon the Earth, this would produce 
but little effect, but upon Mars, whose total permanent water 
area amounts to less than one-third of this area, the effect 
would be vastly greater. Moreover upon the Earth, the semi- 
annual transfer of melted snow from pole to pole is con- 
ducted by means of oceans, but upon Mars this transfer takes 
place across the land. To this fact might reasonably be 
attributed many of the changes in the surface. 
In the last week of June the northern limit of the south 
polar cap was in latitude 65 degrees, corresponding in our 
northern latitude to the northern point of Iceland, some- 
what nearer the pole than we would expect to find it on the 
Earth at the same interval after the Equinox. 
The rapidity with which the snow cap has deapoesel 
would seem to indicate further that the depth of the snow 
deposit on Mars is much less than on the Earth, a result 
which corresponds with the known rarer atmosphere and 
presumably lighter precipitation. 
The testimony of the large telescopes of North America 
except in the case of the Lick Observatory can scarcely be 
said to confirm Schaiparelli’s discoveries. In this connection, 
however, the large southern declination of the planet needs 
to be taken into account. , 
The experience of the present year emphasizes the fact that — 
the erection of large telescopes in localities where the atmos- 
