Meteorological Observations. 167 



and in from four to eight minutes the relief is sufficient for the print- 

 ing of a great number of copies in the ordinary printing-press. 



To prove the applicability of this process, the Commission had a 

 very fine drawing made upon grained zinc and treated by M. Devin- 

 cenzi ; when printed, all the copies exhibited an exact reproduction 

 of the drawing. 



A trial of the effect of the chemical action of the sulphate of copper 

 alone, without the intervention of the electro-chemical action, gave 

 unsatisfactory results ; the outlines of the drawing were not distinct, 

 and several parts were not given. It appears, therefore, that the 

 voltaic action is necessary. Of some plates M. Devincenzi has 

 printed three thousand copies, the last being as fine as the first ; 

 and he considers that zinc, from its presenting more resistance than 

 the alloy of lead and antimony employed in cliches, will allow at 

 least as many copies to be printed from it. — Comptes Rendus, Dec. 31, 

 1855, p. 1226. 



METEOROLOGICAL OBSERVATIONS FOR DEC. 1855. 

 Chiswick. — December 1. Hazy : verj' fine : rain. 2. Cloudy : rain. 3. Clear 

 and frosty. 4. Foggy : drizzly. 5. Clear : overcast. 6. Slight snow : windy at 

 night. 7. Clear : fine. 8. Cloudy and cold. 9. Frosty : cloudy and cold : foggy. 

 10. Overcast : slight snow. 11. Uniform haze. 12. Overcast : sharp frost. 13. 

 Frosty : fine, with sun : clear and frosty. 14. Overcast: rain. 15. Densely over- 

 cast : clondy. 16. Fine: foggy. 17. Foggy. 18. Cloudy and cold. 19. Clear, 

 cold and dry. 20. Frosty, with dry air. 21. Frosty throughout the day : severe 

 Frost at night. 22. Frosty : overcast. 23. Overcast : fine : showery. 24. Very 

 fine : showery at night. 25. Rain. 26. Boisterous, with rain. 27. Rain : cloudy : 

 fine. 28. Very fine. 29. Fine : very fine : sUght rain. 30. Cloudy and fine. 

 31. Fine throughout. 



Mean temperature of the month 34°-99 



Mean temperature of Dec. 1854 39 '35 



Mean temperature of Dec. for the last twenty-nine years ... 39 '64 



Average amount of rain in Dec 1-492 inches. 



Boston. — Dec. 1. Cloudy : rain p.m. 2. Fine. 3. Cloudy. 4. Fine. 5. Cloudy. 



6. Fine : snow a.m. 7. Cloudy : snow p.m. 8, 9. Cloudy : snow a.m. and p.m. 

 10. Fine: snow a.m. and p.m. 11 — 13. Fine. 14. Cloudy : rain a.m. and p.m. 

 15. Cloudy. 16 — 21. Fine. 22. Cloudy : snow a.m. 23. cloudy : snow and rain 

 A.M., and rain p.m. 24. Fine. 25, 26. Cloudy : rain a.m. and p.m. 27 — 29. 

 Fine. 30, 31. Cloudy. 



Sandwick Manse, Orkney. — Dec. 1. Drizzle a.m. : clear p.m. 2. Damp a.m. : 

 damp, vapours p.m. 3. Showers a.m.: drizzly showers p.m. 4. Rain a.m.: 

 showers p.m. 5. Snow-showers a.m. : sleet p.m. 6. Snow-showers a.m. and p.m. 



7. Sleet-showers a.m. : clear, frost p.m. 8. Cloudy a.m.: cloudy, frost p.m. 9. 

 Cloudy A.M. : fine, frost p.m. 10. Cloudy a.m. : showers p.m. 11,12. Snow- 

 showers a.m. and p.m. 13. Cloudy a.m. : showers p.m. 14. Rain a.m. : drizzle 

 p.m. 15. Showers A.M. : showers, thunder and lightning p.m. 16. Hail-showers 

 a.m.: sleet-showers p.m. 17. Fine a.m. : fine, cloudy p.m. 18. Cloudy a.m. : 

 sleet-showers p.m. 19. Cloudy a.m. and p.m. 20. Bright a.m. : Cloudy p.m. 

 21. Bright A.M. : clear p.m. 22. Clear, frost a.m. and p.m. 23. Snow-showers 

 a.m. : rain, clear p.m. 24. Bright a.m. : rain p.m. 25. Bright a.m. : clear p.m. 

 26. Drizzle a.m. : rain p.m. 27. Rain, drizzle a.m. : fine, cloudy p.m. 28. Damp 

 A.M. : rain p.m. 29. Bright a.m. : cloudy p.m. 30. Bright a.m. : clear, aurora 

 P.M. 31. Bright A.M. : cloudy p.m.. 



Mean temperature of Dec. for twenty-eight previous years ... 41°'03 



Mean temperature of the month 39 '41 



Mean tcmjierature of Dec. 1854 39 -13 



Average buantity of rain in Dec. for fifteen previous years ... 4"21 inches. 

 The following are the averages for November 1855, with which we have been 

 favoured by our correspondent the Rev. Ch. Clouston of Sandwick Manse, whose 

 usual report miscarried owing to the stormy weather which then prevailed : — 



Barometer. 



a.m. p.m. 



29-970 29-976. 



Thermometer. 



a.m. p.m. 



43-53 43-46 



Rain 



in inches. 



1-37. 



