Meteorological Observations. 383 



tained, it would be necessary to admit that the hydrofluoric acid, 

 supposed by MM. Gay-Lussac and Thenard to be anhydrous, was 

 really so. 



M. Louyet performed this experiment by the aid of an apparatus 

 which he describes, and the result of it is, that anhydrous hydro- 

 fluoric acid is gaseous at 10" F. at a medium pressure. In this 

 respect it does not differ from other anhydrous hydracids, nor from 

 the fluosilicic nor fluoboric acids. Hydrofluoric acid gas is extremely 

 fuming, on account of its great affinity for water. It acts feebly on 

 glass, and might probably be received in glass vessels over mercury. — 

 Ibid. Mars 11, 1847. 



M 



ETEOROLOGICAL OBSERVATIONS FOR MARCH 1847- 



Chiswick. — March 1. — 3. Cloudy. 4. Fine : cloudy. 5, 6. Cloudy. 7. Slight 

 showers : uniformly overcast ; clear. 8. Small rain : cloudy. 9. Cloudy. 10. 

 Hazy: severe frost at night. 11. Slight haze: cloudy: frosty, 12. Clear. 

 13. Cloudy. 14 — 18. Clear, with bright tun. 19. Clear: cloudy. ^0, 21. Cloudy: 

 clear. 22. Hazy. 23, 24. Cloudy. 25. Foggy : clear : cloudy. 26. Slight 

 haze: fine. 27. Foggy: fine. 28. Uniformly overcast : rain. 29. Very clear : 

 cloudy: frosty. 30. Clear ; cloudy : clear and frosty. 31. Frosty : cloudy. 



Mean temperature of the month 40 "14 



Mean temperature of March 184G 43 -43 



JMean temperature of March for the last twenty years... 42 '91 

 Average amount of rain in March 1'36 inch. 



Boston. — March I — 5. Cloudy. 6. Fine. 7. Fine: rain early a.m. : rain r.:\i. 



8. Cloudy. 9. Fine : snow a.m. and p.m. 10. Cloudy : hail and snow p.m. 

 11 — 13. Fine. 14. Cloudy. 15 — 18. Fine. 19. Fine : a luminous appearance 

 of an extraordinary nature seen in the sky 9 p.m. 20, 21. Cloudy. 22. Fine. 



23. Fine: rain P.M. 24, 25. Fine. 26, 27. Cloudy. 28. Cloudy : rain a.m. and 

 P.M. 29. Fine: thick ice this morning : hail a.m. : rain p.m. 30. Fine: hail 

 P.M. 31. Fine. 



Sandidck Manse, Orkney. — March 1. Cloudy: clear. 2. Bright : clear. 3. 

 Showers : clear. 4, 5. Cloudy. 6. Showers : cloudy. 7. Damp : cloudy. 8. 

 Showers : snow-showers. 9. Snow-showers. 10. Snow : cloudy. 11. Showers: 

 sleet-showers. 12. Showers. 13. Cloudy : showers. 14. Bright : cloudy. 15, 

 16. Cloudy. 17, 18. Bright: cloudy. 19, 20. Bright: clear: aurora. 21. 

 Bright : clear. 22. Bright : large halo. 23. Damp : cloudy. 24. Damp. 

 25. Cloudy. 26. Damp : cloudy. 27. Cloudy. 28. Hail-showers: sleet-showers. 

 29. Shower: clear. 30,31. Snow- shower. 



Applegarlh Manse, Dumfries-shire. — March 1. Thaw: slight rain. 2. Slight 

 frost : very mild. 3. No frost : gray day. 4. Frost, slight. 5. No frost : clear 

 and fine. 6. No frost : dull and cloudy. 7. No frost. 8. Slight frost : clear. 



9. Frost, hard. 10. Frost, hard : sprinkling of snow. 11. Frost: sprinkling 

 of rain p.m. 12. Frost asjain. 13. Fair and moderate weather. 14. Fair, but 

 threatening : change. 15. Fair still, but cloudy. 16. Fair : rain p.m. 17. Rain 

 all day. 18. Very fine: fair. 19. Very fine. 20. Rain: cleared p.m. 21. 

 Heavy showers. 22. Fine : a few drops of rain. 23. Rain a.m. : thunder p.m. 



24. Frosty . fine. 25. Slight frost. 26. Rain. 27. Very fine : rain a.m. 28. 

 Clear and cold : slight snow. 29. Fair ; cold : slight frost. 30. Fair : slight frost. 

 31. Slight snow : hail : frost. 



Mean temperature of the month 42°-5 



Wean temperature of March 1846 42 "2 



Mean temperature of March for 25 years 39 •! 



Mean rain in ^Alarch for 20 years 2*35 inches. 



