Meteorological Observations. 159 



regards the absolute amount of power produced, or the expense, may 

 nevertheless in certain circumstances be usefully and practically 

 applied. 



2. While in the development of great power the electro- magnetic 

 force is very far inferior to that of steam, it becomes equal and even 

 superior to it in the production of small forces, which may be thus 

 subdivided, varied, and introduced into trades and occupations using 

 but small capitals, where the absolute amount of mechanical power 

 is less exerted than the facility of producing it instantaneously and 

 at will. 



3. In this point of view the electro-magnetic force assists, as it 

 were, the usefulness of steam, in place of uselessly competing with it. 



4. Other things being proportional, electro -magnetic machines 

 with direct alternating movement present a great superiority of the 

 power developed over rotating machines ; since in the first there are 

 no components lost, and with the same expense a much more consi- 

 derable power is obtained than with rotating machines. 



5. In machines of direct movement, the influence of the currents 

 of induction appears less considerable than in rotating machines. 



6. Finally, in the calculation of the expense, it is proper to include 

 deduction of the value of the sulphate of zinc produced, and to take 

 into consideration, that, in apparatus of any considerable size, the 

 same battery may be used at the same time for the production both 

 of the power and light. — Comptes Rendus, August 25, 1851. 



METEOROLOGICAL OBSERVATIONS FOR DEC. 1851. 



Chiswick.— December 1. Frosty: fine: uniformly overcast at night. 2. Over- 

 cast : clear. 3. Hazy : cloudy : frosty at night. 4. Frosty : fine. 5. Hazy : 

 cloudy : overcast. C. Densely overcast. 7. Fine : cloudy. 8. Cloudy : clear and 

 very fine. 9. Foggy. 10. Cloudy. 11. Clear and fine. 12. Very dense fog. 

 13. Foggy: hazv throughout. 14. Foggy. 15. Hazy. 16. Foggy: overcast. 

 17, 18. Foggy. 19. Very fine. 20. Hazy and drizzly : densely overcast at night. 

 21. Rain : boisterous at night. 22. Rain : clear at night. 23. Clear and line. 



24. Hazy : fine. 25. Clear and fine : cloudy at night. 2C. Fine : sharp frost. 

 27. Frosty : overcast : slight rain. 28. Fine : densely clouded : clear. 29. Slight 

 haze. 30. Foggy. 31. Frosty and foggy : hazy. 



Mean temperature of the month 38 -88 



Mean temperature of Dec. 1850 38 "47 



Mean temperature of Dec. for the last twenty-six years ... 39-69 



Average amount of rain in Dec 1'52 inch. 



Boston.— Dec. 1. Fine. 2—4. Cloudy. 5. Cloudy: rain a.m. 6. Cloudy. 



7—9. Fine. 10. Cloudy : rain p.m. 11,12. Fine. 13. Foggy. 14—19. Cloudy. 



20. Fine. 21. Rainy : rain a.m. and p.m. 22. Cloudy. 23. Fine. 24. Cloudy. 



25, 26. Fine. 27. Cloudy. 28. Cloudy : rain p.m. 29, 30. Cloudy. 31. Fine. 

 Sandwick Manse, Orkney. — Dec. 1. Cloudy: damp. 2. Damp. 3. Showers: 



damp. 4. Rain : showers. 5. Showers : drizzle. 6. Bright : drizzle. 7. Cloudy. 

 H. Damp: showers : clear. 9. Damp : drizzle. 10. Cloudy : rain. 11. Damp: 

 drizzle. 12. Bright ! cloudy. 13. Drizzle: clear. 14. Fine. 15. Fine: damp. 

 16. Bright: fine: damp. 17. Damp: line: damp. 18. Bright: fine: aurora. 

 19. Cloudy: fine: aurora. 20. Cloudy : drizzle. 21. Rain : clear : aurora. 22. 

 Frost : clear : aurora. 23. Brighl : clear: aurora. 24. Frost : aurora. 25. Frost : 

 cloudy. 26. Fine : clear : aurora. 27. Fine ; cloudy. 28. Cloudy. 29. Cloudy : 

 damp. 30. Drizzle : rain. 31. Drizzle : cloudy. 



