Prof. Forbes on the Colour of Steam. 



121 



4. 



5. 



6. 



7. 



8. 



9. 

 10. 

 11. 

 12. 

 V6. 

 14. 

 15. 

 16. 

 17. 

 18. 



ly. 



20. 

 21. 



22. 



Spanish Town 



Tobago 



Port Antonio 



Up Park Camp 



Dominica 



St. Lucia 



Port Royal 



Trinidad 



Fal mouth 



Stony Hill 



British Guiana 



Lucea 



Fort Augusta 



St. Kits, Nevis and Tortola 



Grenada 



Barbadoes 



St. Vincents 



Antigua and Montserrat 



Maroon Town 



Deaths in 

 ICOO. 



Deaths by 

 Fever. 



162—4 



152—8 



149—3 



140—6 



137—4 



122—8 



113 — 1 



106—3 



102—6 



90—2 



84-0 



84—9 



73—5 



71—0 



61—8 



58—5 



54—9 



40—6 



32—7 



141—1 

 104—1 

 126—0 

 120—8 

 49—3 

 63—1 

 93—9 

 61—6 

 80—0 

 70—5 

 59—2 

 63—2 

 55—5 

 42—1 

 26—3 

 11—8 

 11—2 

 14-9 

 15—3 



The most sickly as well as the most fatal period of the year 

 extends irom August to December, and during this time the 

 winds are generally from the south and west. The least un- 

 healthy months are March, April, and May, when the trade- 

 whid blows from the east. The annual mortality of the troops 

 in England has for a long series of years been only fifteen 

 to the thousand. 



1 



XXI. On the Colour of Steam under certain circnmstances. 

 By Professor Forbes*. 



N the end of May or beginning of June last, I happened to 

 stand near a locomotive engine on the Greenwich railway, 

 which was discharging a vast quantity of high pressure steam 

 by its safety valve. I chanced to look at the sun through 

 the ascending column of vapour, .and was struck by seeing 

 it of a very deep orange red colour, exactly similar to dense 

 smoke, or to the colour imparted to the sun when viewed 

 through a common smoked glass, 



1 did not pay much attention to the fact at the moment, nor 

 did 1 attempt to vary the experiment; but reflecting on it af- 



Communicated by the Author. 



