Trigonometrical Survey . 43 1 
art. v. Table, containing the Particulars of the Measurement: the first 
Column showing the Day of the Month when each Hypotenuse was fi- 
nished; the Second, the Number of Hypotenuses ; the Third, the Num- 
ber of Chains in each Hypotenuse ,- the Fourth, the Perpendicular be- 
longing to each Hypotenuse, or the datum for reducing it to the Plane 
of the Horizon ; the Fifth, the computed Reduction ; the Sixth, the new 
Points of Commencement above or below the Head of the last Picket 
when a new Direction was taken ; the Seventh, the total Descent of the 
Extremity of each Hypotenuse ; and the Eighth, Remarks, or general 
Occurrences. 
1 79 1 - 
Month. 
No. of 
hypoten. 
No. of 
chs. in 
hypoten. 
Perpen- 
dicular. 
Reduction 
of 
hypotenuse. 
New 
point of 
comm*. 
Total 
descent. 
Remarks. 
Inches. 
Inches. 
Inches. 
Inches. 
The 1st chain commenced 14 
Aug. 15 
I 
3 
5,8 
0,00467 
1,8 
19,8 
inches above the head of Ge- 
16 
2 
3 
0,0 
0,00000 
21,6 
neral Roy’s pipe before it 
22 
3 
3 2 
57* 
0,042 ;i 
35*4 
was cut off smooth. 
23 
4 
14 
26,25 
0,02051 
4*9 
61,65 
Began measuring with chain A 
25 
5 
10 
12,1 
0,00610 
7*9 
68,85 
at 4th hyp. one of the links on 
29 
6 
19 
0,0 
0,00000 
60,95 
the chain B appearing to be a 
Sept. 2 
7 
34 
28,8 
0,01017 
89,75 
little bent. [8thhypot. 
4 
8 
1 
3,8 
0,00602 
85,95 
Crossed the river Coin at the 
6 
9 
15 
69,25 
0,13321 
4*25 
155*20 
Crossed the Staines road at the 
8 
10 
17 
iS*3 
0,00574 
166,25 
9th hypotenuse. 
9 
1 1 
5 
33*5 
0,09352 
199*75 
12 
12 
13 
i*9 
0,00012 
8,25 
201,65 j 
' 
12 
13 
7 
54*5 
0,17680 
247*90 
r 3 
H 
6 
0,0 
0,00000 
5*25 
247*90 
H 
IS 
5 
7*5 
0,00469 
250,15 
14 
16 
9 
0,0 
-0,00000 
9*5 
250,15 
16 
1 7 
8 
5*3 
0,00146 
245,95 
17 
18 
10 
2,9 
0,00035 
248,85 
20 
l 9 
S 
4,8 
0,00192 
253*65 
20 
20 
4 
8,1 
0,00683 
261,75 
21 
21 
8 
!*5 
0,00012 
260,25 
21 
22 
6 
35*4 
0,08703 
295,65 
22 
23 
1 
6,4 
0,01707 
302,05 
Crossed the Wolsey river at the 
23 
24 
10 
H*5 
0,00876 
316,55 
23d hypotenuse. 
25 
25 
12 
54*4 
0,I027£ 
370,95 
25 
26 
1 
24*5 
0,25015 
346>45 
25 
27 
5 
1,0 
0,00001 
345*45 
26 
28 
5 
H*3 
0,01064 
35'6*75 
26 
29 
1 
9,0 
0,03375 
365*75 
The head of the last picket 
was z\ feet above the head of 
26 
30 
S 
6,9 
0,00397 
372,65 
the pipe before it was cut off 
smooth. 
Tot 
al reduction — 
1,02867 
=0,085 
;72feet. 
Sum of all the degrees shown by the thermometers = 96795,25. 
3 K 2 
