1811. 
BOTANICAL EXPERIMENT. 
133 
direction by ferruginous rocks, the angular distances of the objects 
from each other will remain correct. It is not indispensably requisite 
that all the lines of bearing should pass through one central point in 
the meridian line, as they may at leisure, any time afterwards, be 
transferred to a centre by means of a parallel ruler ; and, the paper 
being then properly placed on the map, the bearings may be pricked 
through, by which the purpose of a protractor is answered very accu- 
rately. On this principle, a traveller may construct a simple and port- 
able instrument, by a circular piece of wood, in the centre of which 
is fixed a short pin with a pointed top. On this, at the time of ob- 
servation, a piece of paper of the same size is filed ; and over it is 
fixed a moveable limb with sights, having its fiducial line correspond- 
ing with the centre of the pin. A magnetic needle may be added 
to the instrument, if not rendering it too complicated. 
Loaded on all sides with flowers and branches of shrubs, we 
descended to the plain ; and those who met us as we were returning 
to Tulbagh, might have thought, as in Macbeth, that " Birnam-wood 
was come to Dunsinane." Night overtook us before we reached the 
parsonage, where hospitality and good humour concluded the day. 
IStk. My first care this morning was to preserve the botanical 
specimens which I collected yesterday ; and, as I had not the means 
of pressing and drying them in the usual manner between paper, I 
tied them carefully up in a large bundle, measuring about three feet 
long and a foot in diameter, binding them round as tightly as pos- 
sible with twine, and wrapping the whole with strong paper. This 
I left to be sent after me to Cape Town by the first opportunity, in- 
tending afterwards to press and dry them properly. 
This bundle, however, did not find its way to Cape Town till 
more than a twelvemonth afterwards, and remained in the same 
state for eight years, when, on unpacking it, every specimen was 
found to be in as good condition as if it had been dried in 
the regular manner, and to be equally fit for every purpose of 
scientific investigation. A few, indeed, were the worse for having 
been left to shrivel up ; but many, especially the more hard-leaved 
plants, preserved a more natural form than they would have done, 
