if 
| Therm: below dt.) Phil. Mag. Ser.A.Nol, 21. PLVL. 
| 20 
bo 
2. Lee J | 
| 
a 
750° 
See OTL STII 
oO 
9) | 
a eee 
| 
| RBerres 
| 
: 
| 
J) Basie litho. 
