CHAP. 111.] THE CRUISES OF THE ‘ PORCUPINE,’ 139 
for the purpose of investigating the bottom of the Ocean by 
means of deep-sea soundings, will be entertained whilst embarked 
on board the ‘ Porcupine’ at the Government expense. 
“Tam, Sir, 
«“ Your obedient servant, 
“'W. G. RoMAINE.” 
“The President of the Royal Society.” 
June 17, 1869. 
Read the following Report :— 
“The Committee appointed Feb. 18, 1869, to consider the 
Scientific Apparatus it will be desirable to provide for the pro- 
posed Expedition for Marine Researches, beg leave to lay before 
the Council the following Report :— 
“The chief subjects of Physical Enquiry which presented 
themselves as interesting on their own account, or in relation to 
the existence of Life at great depths, were as follows :— 
“(1) The temperature both at the bottom and at various 
depths between that and the surface. 
“(2) The nature and amount of the dissolved Gases. 
“(3) The amount of Organic matter contained in the water, 
and the nature and amount of the Inorganic salts. 
“(4) The amount of Light to be found at great depths. 
“ Among these subjects the Committee thought it desirable to 
confine themselves in the first instance to such as had previously 
to some extent been taken in hand, or could pretty certainly be 
carried out. 
“The determination of Temperatures has hitherto rested 
chiefly upon the registration of mznimum Thermometers. It is 
obvious that the temperature registered by minimum thermo- 
meters sunk to the bottom of the sea, even if their registration 
were unaffected by the pressure, would only give the lowest 
temperature reached somewhere between top and bottom, not 
necessarily at the bottom itself. The temperatures at various 
depths might indeed, provided they nowhere increased on going 
deeper, be determined by a series of minimum thermometers 
placed at different distances along the line, though this would 
