172 E. LANCASTER JONES 
in which the residual m’s multiplied by the coefficient 2 belong to all 
those rectangles in external contact with the first-remove rectangles, 
and those multiplied by the coefficient unity belong to those rectangles 
in contact with the common second-remove rectangles. There may 
be as many as four of the former and eight of the latter. 
By a similar procedure of selecting suitable multipliers and sum- 
ming the equations, it is possible to obtain for any correlate formulae 
which involve the elimination of all or most of the correlates of cells 
which are adjacent to the key cell, and therefore give a better first 
approximation than the preceding equations (11), (12), (14) and (15). 
This advantage is, however, more than counterbalanced by the in- 
creasing complexity of the residuals and series of excess terms, and 
for practical purposes either equations (11) or equations (12), (14) 
and (15) are recommended for use with a rectangular network. 
Single chain of rectangles. In the particular case of a single chain 
of rectangles, as in Figure 4 
Sle, | Ge | ale | Sax | S| Gah | oy | See | Ste 
FIG. 4 
there is some advantage in forming the equation for any correlate m 
of cell S, by eliminating pairs of cells on either side of it as far as sym- 
metry permits, say, to the cells S—3 and S+3. We have the correlate 
equation coefficients shown in Table V. 
TABLE V 
m 
Xby 
S—4|S—3 | S—2|S—1 S$) S+1 | S+2}S5+3 | $+4 
veboleyl/ to We aa aeiliee clea 
fo en ee al el 
Taras clint bese saeeloss? cloaca, wake 
aiifeli {leon we ae |usbes bade Wer Sel 0 biwettl| ay tein 
UE dias ka I Asse 
re Bere a |e ak GR isco 
7s ie ies cps GAL Md TM ese) 


And using the multipliers 1 for S—3 and S+3, 4 for S—2 and S+2, 
(4X4—1) or 15 for S—1 and S+1, and (4X15—4) or 56 for S, and 
adding, we get 
832 
