( 690 ) 
it 
dx; dR’ 
er 
dt OTK 
0 
From the value (3) of A’ we find easily (remembering that 
Qh =n; == tte or nd rl a) 
yi 
1 dx, a, A 
Ve dt = — m, —— cos a, 
2 dt a, €, 
0 
FT 
Bd el Re as Aran 
mn OE OSE m Mr COST 
ee Dare) “dt Te °) "as & 
. T 
Sioa tr al iets 
‘ SS nl I COS CL, Dd). 
teh hy vat ie eee 
0 
The conditions (1) can thus be written 
xT x 
S= = 2S = =—- 
27 p 
== 
| a | p a B 
QO | Oo > 
wey wit > | 2. 
(1) Os OLS Oe? OF | — | 0) +] aapessible, 
(2) 0 0 | 0 180 |— ,O | — | conditional. 
(3) 0 0 180 0 — + —| impossible. 
(4) 0 0 180 180 |— + + | impossible. 
(5) 0 | 180 | 0 0 os + | impossible. 
(6) 1-0.) 480° | | 4g0 |l =| paseible: 
(7) Oel 480.4 480/170 — | O | — | conditional. 
(8) 0 | 180 } 480 | 480 | — | O + | impossible. 
(9) [190 0 | 0 | 0 — | + | impossible. 
do) [aso | o | o | 480 jess _— | impossible. 
(14) | 180. | 0 | 480 | © impossible. 
(12) $480 | oO | 480 | 480 
| + | conditional. 
+ | conditional. 
(13) | 180.) 4802 pO — 40 
> 
Go 
a) 
14) | 180 | 480 | 0 
(15) | 420 | 180 | 480 | 0 | — | impossible. 
dd tk + 
O 
O 
O 
O | — | impossible. 
as 
Be 
(16) | 480 | 480 | 180 | 4180 ‚+ | possible. 
