Meteorological Observations. 79 



by there being no longer any chloride of silver visible on stirring the 

 precipitate. The silver thus procured is to be washed with water, 

 and any small residue of chloride of silver which it sometimes retains 

 may be got rid of by diluted ammonia. 



The silver thus prepared is perfectly pure. It is readily seen that 

 any foreign metals that may be contained in the zinc, can never mix 

 with it, as the disc of zinc lies during the whole operation below the 

 cup containing the silver, and never comes in contact with it. — 

 PoggendorfF's Annalen, vol. Ixxxv. p. 462. 



THE BOMERANG. BY J. E. GRAY. 



If a common manilla or palm-leaf hat having a low crown, and 

 the margin of the rim sharply turned up about half an inch high, is 

 thrown into the air with the cavity of the hat upwards, it returns 

 back towards the thrower like the Australian bomerang. The angle 

 at which it returns depends on the angle at which it is thrown ; and 

 if the angle is sufficiently acute, it will fall some distance behind the 

 thrower. 



The experiment depends on the position of the hat ; for if thrown 

 with the cavity downwards, it alights in the direction thrown, and 

 does not return. A pasteboard disc with a turned-up edge has the 

 same effect as a hat. 



METEOROLOGICAL OBSERVATIONS FOR MAY 1852. 



Chiswick. — May 1. Overcast: cloudy: clear. 2. Cloudy and cold: frosty at 

 night. 3. \Miite clouds : fine : clear and frosty. 4. Dusky clouds : clear and 

 frosty. 5. Densely clouded : clear and frosty at night. 6. Cloudy : clear. 7. 

 Overcast: veiy fine. 8. Cloudy: fine. 9. Fine. 10. Fine: rain at night. 11. 

 Boisterous, with heavy shower, partly hail. 12. Heavy rain: thunder. 13. Cloudy: 

 overcast : boisterous at night. 14. Showery and boisterous : clear. 15, 16. Very 

 fine. 17. Slight drizzle : overcast : thunder, lightning and rain at night. 18. Very 

 fine: rain at night. 19. Very fine. 20. Hazy: fine: showers. 21. Overcast. 

 22. Cloudy : clear. 23. Cloudy. 24, 25. Overcast : fine. 26. Rain. 27. Over- 

 cast. 28. Densely clouded. 29. Rain. 30. Fine: cloudy. 31. Fine: cloudy: 

 clear and cold. 



Mean temperature of the month 51°'45 



Mean temperature of May 1851 51 "16 



Mean temperature of May for the last twenty-six years ... 54 -07 

 Average amount of rain in May 1*74 inch. 



Boston. — May 1. Cloudy. 2. Cloudy: rain a.m. 3,4. Cloudy. 5. Cloudv : 

 rain a.m. C. Cloudy. 7. Fine. 8. Cloudy. 9, 10. Fine. 11. Cloudy. 12— 

 14. Cloudy : rain A.M. 15, 16. Fine. 17. Cloudy. 18. Cloudy : rain a.m. and p.m. 

 19. Cloudy : rain a.m. 20. Fine. 21. Cloudy : rain a.m. and p.m. 22 — 25. Cloudy. 

 26. Cloudy : rain P.M. 27— 29. Cloudy. 30. Fine. 31. Cloudy. 



Sandwick Manse, Orkney. — May 1. Cloudy: fine. 2. Clear: fine. 3. Cloudy! 

 fine : clear : fine. 4. Cloudy : fine. 5. Drops : fine : cloudy : fine. 6. Clear 

 fine : cloudy : fine. 7. Drops : rain : clear. 8. Drops : showers. 9. Rain : clear 

 10. Drops: clear : aurora. 11. Cloudy : showers. 12. Bright : clear. 13. Rain 

 clear : fine. 14. Bright : showers. 15. Clear: cloudy. 16. Clear. 17. Clear 

 fine. 18, 19. Clear : fine : aurora. 20 — 23. Clear : fine. 24. Bright : fine : clear 

 fine. 25. Clear: fine. 26. Cloudy. 27. Cloudy: fine. 28. Bright: cloudy 

 showers. 2'J. Bright : showers : cloudy : hail-showers. 30. Sleet-showers. 31 

 Sleet-showers : showers. — This month has been fine, warm and dry. 



Mean temperature of May for twenty-five years previous ... 47°"88 



Mean temperature of this month 50 "49 



Average quantity of rain in May for six years 172 inch. 



