Hello fellows in sundialling
I assure you I strived a lot to avoid bringing this problem to you.
I can not hide from you the fact that it humilates me. But I still
think my ignorance chagrins me more than my failure. So, here
I am, humbly asking you to help me one more time with something
that should be a child's play... but is knocking me down. Perhaps
because I am not a child?
Following the instructions found on pages 78-85 of
Albert E. Waugh's "Sundials - Their Theory and Construction"
I built a N 20 W decliner. It is in place and working fine.
Than I went to build the dials for the other faces. Alas! After two
weeks
of nightly work I am still mystified, completely bewildered with the
results
I gotten so far.
Applying the recipé I found the following:
(The algorithm is described pages 78-86.)
Data: Phi = 15.7513
Wall: E 20 N
The angles I found are:
SD (sub-style distance) = -50.4886 (tan SD = sin D * cot Phi)
SH (style height) = 64,7434 (sin SH = cos D + cos Phi)
DL (difference in longitude) = -53,2830 (cot DL = cot D * sin Phi)
AV (6o'clock angle ) = 84.4898 (cot AV = sin D * tan Phi)
Converting DL into time units I have 3,5522 = 3 h 33 m 8 s
Hour angles from sub-style position are as follows:
1 113.76
2 97.42
3 80.85
4 64.55
5 48.88
6 34.00
7 19.80
8 6.07
Sub-style
9 7.50
10 21.26
11 35.52
12 50.48
13 66.23
14 82.58
15 99.14
16 115.44
17 131.11
18 145.99
19 160.19
20 173.92
21 187.50
22 201,26
23 215.52
24 230.00
I've calculated the hour for a full 24-hour dial just as a way to double
check my calculation. Also, I've done all the number checking that
the author recomends. They all indicate the results are good.
Nevertheless, when I built the model and put it in place... it does not
work.
Can somehelp me before I lose my hair?
Something must be wrong. But what? What?
- fernando
PS -- Both Abert Waugh and René R. J. Rohr say that in a vertical dial
the 12 o'clock line is always vertical. Nevertheless, I've noticed this
is not the case for a vertical direct west (or east) dial. Have I found
a hint here?
--
Fernando Cabral Padrao iX Sistemas Abertos
mailto:[EMAIL PROTECTED] http://www.pix.com.br
mailto:[EMAIL PROTECTED]
Fone: +55 61 321-2433 Fax: +55 61 225-3082
15º 45' 04.9" S 47º 49' 58.6" W
19º 37' 57.0" S 45º 17' 13.6" W
