34 
Proceedings of the Royal Society 
This means of putting on the thermometer is a great saving of 
time and trouble. The thermometer has been found to answer 
admirably. 
When each sample is taken the following observations are made 
and recorded : — 
Date. 
Hour of collection. 
Position by bearings. 
Depth of water.* 
Depth from which sample was taken. 
Temperature of the water at that depth. 
Temperature of the air. 
Nature of the weather, wind, and state of the sea. 
State of tide. 
Colour and transparency of the water.* 
The colour of the water is observed by sinking a disc of iron, painted 
white, to the depth of a few feet or fathoms, according to circum- 
stances, and noting its colour. The transparency may be roughly 
measured by observing the distance to which the disc remains 
visible. 
It is important that the actual notes of all observations be pre- 
served for future reference should uncertainty arise regarding them. 
There are difficulties in doing this, for it is not easy on a small 
vessel when there is any sea on to keep an ordinary note-book 
from getting wet, especially when it is raining ; and turning wet 
pages in a breeze is not easy. I have employed a leather case 
to hold a note-book, using one page for each set of observations, and 
keeping it shut when not in use. The principal objection to this 
is the unwieldy size of the case, and I now propose to use cards, 
with memoranda of the observations to be made printed on them, 
and kept in a similar though much smaller case. As each card is 
used it may be slipped beneath the others, as is done in a date- 
case. The cards can be very easily kept in boxes, and may be 
readily and rapidly referred to at any time. 
* These are sometimes omitted in the case of surface samples. 
