70 G ALTON ON THE EXPLORATION OF ARID COUNTRIES. [Dec. 14, 1857. 
Extreme distance attainable . — I next give a Table which shows the 
extreme distance to which a reconnaissance may be effected in the 
three simple cases of the binary system, and the total number of 
men, including the exploring party, that would be required to work 
it. The explorers are supposed to carry provisions just as their 
supporters do. If one or more of them be exempted from porterage, 
the extreme distance that can be reached will be somewhat 
diminished 
Table 9. 
No “ repeti- 
tion ” em- 
ployed. 
First stage 
repeated. 
First and 
second stages 
repeated. 
Number of days’ rations conveyed) 
by each member of the entire ex-> 
pedition . . . . j 
1* 
3| 
n 
3| 
11 
4 
8 
Number of additional days’ journey) 
required owing to the employment! 
of “repetition” j 
0 
0 
0 
i 
2 
3 
12 
Organization. 
/E 
Organization jg j_ e 
and numbers ) ™ T ’ n * ’ 
of the entire | +; + + 2 * e 
expedition. I ' & c ~ 
Total 
number. 
e 
2e 
4e 
8e 
&c. 
1 
i* 
2 
21 
2 
31 
4 
H 
3 
41 
6 
1| 
2 
2£ 
3 
3§ 
4 
5 1 
6 
4* 
6 
n 
9 
2 
21 
3 
3J 
4 
5 
6 
7 
5 
n 
9 
10* 
Extreme dis- 
tance attainable. 
When men only are employed, e refers to their number ; but when 
horses and men are employed together, e stands for the number of 
horses, each of which is supposed to be accompanied by one or two 
men, and carries provisions accordingly. ( See Table 2.) 
We may therefore conclude that it is easy to organise an expe- 
dition, on the binary method, which shall be able to reach and to 
return from points in the heart of the desert at the below-mentioned 
distances, without the sacrifice of a single meal, and without obtain- 
ing any other provisions than those carried by it from the camp 
whence the start was made : — 
Table 10. 
In a grassy but waterless 
country. 
In a perfectly barren country. 
By caravans composed — 
From 7 to 9 days’ journey. 
of Horses in harness 
From 4 to 6 days’ journey. 
of Pack horses 
, , 4 to 6 , , 
, , 2 to 3 , , 
of Parties of men . . 
, , 2 to 3 , , 
, , 2 to 3 , j 
I need not enlarge on the vast increase of field that the adoption 
of the above method woidd give to the excursions of an explorer. 
