Meteorological Observations. 



427 



Mean value of a n=l-7 inch. 



The latitude of the Philosophical Institution is 5 1° 27' 1 6", the sine 

 of which X 15° 2' 28" (=the angle through which the earth rotates 

 in 1 hour oi mean time) gives 11°*7638. 



The set of long experiments performed at St. Nicholas gave a 

 mean motion of 1 1°-750 per hour, instead of 1 1°-763I as per theory, 

 the latitude being 51° 27' 0". 



The close agreement thus obtained between theory land experi- 

 ment, by two very different pendulums, and at two different stations, 

 not only confirms the truth of Foucault's hypothesis, but seems to 

 show that the latitude of a place may be found, by means of this 

 experiment;, with a considerable degree of accuracy. 



I am. Gentlemen, Youj-s respectfully, 

 7 Nugent Place, Bristol, Thomas G. Bunt. 



17th October, 1851. 



METEOROLOGICAL OBSERVATIONS FOR SEPT. 1851. 

 Chiswick. — September 1. Cloudy and fine : overcast. 2. Drizzly : cloudy and 

 fine. 3. Hazy: very fine : clear. 4. Foggy: cloudy: fine. 5. Very fine: 

 clear. 6. Fine: cloudy. 7. Clear: very fine. S. Overcast: cloudy and fine. 

 9 — 13. Mornings foggy : days very fine: nights clear. 14. Slight fog : very 

 fine. IS. Slight fog : cloudy and fine. 16. Light clouds and fine : over- 

 cast. 17. Overcast: fine: cloudy. 18,19. Fine: clear. 20 — 22. Very fine* 

 23. Slight fog: very fine: rain. 24. Foggy: overcast: foggy at night. 25. 

 Slightly overcast : rain. 26. Partially overcast : cloudy : clear. 27, Cloudy : 

 drizzly. 28. Clear and fine. 29. Foggy : fine. SO. Rain : overcast, 



Mean temperature of the month 55°'l5 



Mean temperature of Sept. 1850 54 -23 



Mean temperature of Sept. for the last twenty-five years . 57 '18 



Average amount of rain in Sept 261 inches. 



Boston. — Sept. 1, Fine. 2. Cloudy : rain early a.m. and p.m. 3 — 5. Cloudy. 

 6. Fine. 7. Cloudy. 8— 11. Fine. 12, 13. Foggy. 14. Fine. 15— 17. Cloudy. 

 18, 19. Fine. 20. Cloudy. 21 — 23. Fine. 24. Cloudy. 25. Cloudy: rain p.m. 



26. Cloudy : rain a.m. and p.m. 27. Cloudy. 28, 29. Fine. 30. Cloudy. 

 Sandwick Manse, Orkney. — Sept.]. Drizzle : -^ damp. 2. Cloudy: rain. 3. 



Drizzle : cloudy. 4. Clear : aurora. 5. Clear. 6. Bright : cloudy. 7. Cloudy : 

 clear: aurora. S.Clear. 9. Bright : hazy. 10. Cloudy : drops. 11. Cloudy: 

 fine. 12, 13. Bright : fine : clear. 14. Bright: cloudy. 15. Cloudy : clear : 

 aurora. 16. Bright : clear : aurora. 17. Bright: clear. 18, 19. Fog: cloudy. 

 20. Showers: clear. 21. Cloudy. 22. Drops: drizzle. 23. Bright: clear: 

 aurora. 24, Clear : cloudy. 25. Showers : sleet- showers. 26. Bright : showers, 



27. Clear : showers : aurora, 28. Bright ; showers : aurora. 29, Cloudy, 30, 

 Cloudy; showers. 



