between the White and Blood-Red Heat 841 



Effect of Iron at different Degrees of Heat on the Compass. 



No. 1. South end drawn to the bar at red heat. 



No. 6. This bar being left standing, it attracted the same three days after. 



No. 8. The needle suspected to touch the box. 



Nos. 11. to 24. Observed at the same time with two compasses. 



No. 25. N. end drawn to the bar at red heat. No, 26. Attractions very gradual. 



No. 27. Passed suddenly to 12^, but returned immediately. 



Nos. 28. and 29. Attractions gradual. 



No. 30, Negative attraction rather sudden. No. 31. Motion of needle very slow. 



No. 32. 100 very sudden, returned immediately. No. 33. Both attractions gradual. 



No. 34. The same as No. 32 ; both anomalous. No. 35. Attractions very gradual. 



No. 37. Motion regular, but quick. No. 38. No motion in the needle. 



