SD WO Wl OH | 19 19 SH OD OD 
LD LD 1 1 1 LD 
Mean Re- | 
fraction. 
Ppetent 
itude. 
t 
uu 
fraction. 
Mean Re- 
Altitude. 
Mean Re- | Apparent 
fraction. 
= 
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3 
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| 
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o 
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4 
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E 
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g 
= 
Altitude. - 
Mean Re- | Apparent 
fraction. 
[Barometer, 30 inches. 
Altitude. 
Mean Re- {| Apparent 
fraction. 
Page 150] 
Apparent 
Altitude 
