Table No . Page 



28 Reduction of Barometric Reading to Mean Sea Level 130 



29 Reduction of Mercurial Barometer to Standard Gravity 130 



29A Millimeters to Millibars 130 



30 Q-Code Signals (Selected) 131 



Chart 



Figure 



CHARTS 



1 Greenwich and Local Time 133 



LIST OF ILLUSTRATIONS 



1 Ship's Weather Observations --Form 615-5 4-5 



2 Surface Wind at Sea--Form 1209 25 



3 Plotting Board for Finding True Wind at Sea 26 



4 Non-Uniform Visibility 32 



5 Aneroid Barometer 48 



6 Barograph, Marine Model G-220 50 



7 Barograph Chart 51 



8 Barograph, Marine W. B. Model G-222 53 



9 Sling Psychrometer 62 



10 Psychrometer (Portable, Aspirated, Electric) 63 



11 Section of Trace from Wave Recorder 83 



12 Wave Length and Height 85 



VIII 



