6 1 Vegetable Staticks. 



numb. 6, 24 inches underground. And that 

 the heat of the earth, at thefe' feveral depths, 

 may the more accurately be known, it is 

 proper to place near each 'Thermometer a 

 glafs-tube fealed at both ends, of the fame 

 length with the items of the feveral Ther- 

 mometers ; and with tinged fpirit of wine 

 in them, to the fame height, as in each 

 correfponding Thermometer ; the fcale of 

 degrees, of each Thermometer, being mark- 

 ed on a Aiding ruler, with an index at the 

 back of it, pointing to the correfponding 

 tube. When at any time an obfervation is 

 to be made, by moving the index, to point 

 to the top of that fpirit in the tube, an ac- 

 curate-allowance is hereby made, for the 

 very different degrees of heat and cold, on 

 the ftems of the Thermometers , at all depths ; 

 by which means the fcale of degrees will 

 {hew truly the degrees of heat in the balls 

 of the Thermometers, and confequently, the 

 refpedlive heats of the earth at the feveral 

 depths where they are placed. The ftems 

 of thefe Thermometers, which were above 

 ground, were fenced from weather and in- 

 juries by fquare wooden tubes -, the ground 

 they were placed in was a brick earth in 

 the middle of my garden. 



A 



