on the Distribution of the Magnetic Intensity. 



37 



OBSERVATIONS AT THURSO. 



The Observations were made west of the Town, on the Pennyland Estate, in the field in 



front of the House. 



CYLINDER, No. I. First Arc 40. 



CYLINDER, No. I. First Arc 40. 



CYLINDER, No. I. First Arc 40. 



FLAT NEEDLE. First Arc 30. 



