Mr. Nixon's Theory of the Telescopic Level. 423 



frequently attached a small barb of quill or fine iron, so as to 

 assist more effectually in rendering extraction almost impos- 

 sible. With the view of ensuring the arrow a straight course 

 when ejected from the bow, they in common with all others 

 who use the like instrument, attach a portion of feather to its 

 hinder extremity < Of such, thus completed, every Bushman 

 will perhaps be supplied with fifty or sixty, and those he car- 

 ries in a sort of quiver, formed of the bark of the Kokkerboom, 

 from which the woody part has been excavated. When, how- 

 ever, in a state of war, or in pursuit of game, he generally holds 

 more or less loose in his hand, and when about to shoot, al- 

 ways places them in a convenient situation upon the ground. 



The poison they employ is manufactured in various ways, so 

 as to concentrate and render it adapted for application to the 

 arrows. The most virulent sort, and that which they usually 

 employ when they go against their enemies, is chiefly com- 

 posed of the poison of snakes; the next to that is one ob- 

 tained from the larvae of an insect, found upon a bush grow- 

 ing near the Orange River ; and the third is of vegetable 

 origin, and called the malkop poison, on account of the pecu- 

 liar effects it produces upon the senses. This last is not con- 

 sidered so serious in its consequences as either of the others, 

 and is the sort commonly employed upon arrows destined for 

 killing game. 



Such then are a few of the points of interest connected with 

 the history of the Bushmen ; and though far from exhausting 

 the subject, or even including all that my own notes would 

 afford, yet I am induced to conclude for the present, with an 

 earnest recommendation to such of the members as may have 

 been in the habit of observing our savage tribes, to embody 

 their remarks for occasions like the present; as by such pro- 

 ceedings they may advance their individual reputations, at the 

 same time that they acquire a consequence and character for 

 our institution, which must be dear to all of us who feel a pride 

 in the success of enterprizes in which we have a share. 



LXIV. Theory of the Telescopic Level. By JOHN NIXON, Esq.* 



A TELESCOPIC level of the most simple construction, 

 *"* would consist of a refracting telescope with adjustable 

 cross wires fixed within a perfectly cylindrical tube ; the latter 

 having attached to its surface (by means of adjusting screws) 

 a spirit-level, placed parallel to the direction of its axis. 



* Communicated by the Author. 



When 



