28 Inquiry concerning the Nature of Heat, 



naked instrument always served as a standard, with 

 which the results of the experiments made with the 

 other were compared, it is evident that this arrange- 

 ment rendered the general results of the experiments 

 much more satisfactory and conclusive than they could 

 possibly have been, had the experiments made on differ- 

 ent days and with various kinds of covering been 

 made singly, or unaccompanied by a fixed and invari- 

 able standard. 



The experiments were made and registered in the 

 following manner: The two instruments used in the 

 experiment, placed on their wooden stands, being set 

 down on the floor, were filled to within about \\ inch 

 of the tops of their cylindrical necks with boiling hot 

 water ; and, a thermometer being put into each of them, 

 they were placed at the distance of three feet from each 

 other, on a large table, in a corner of a large quiet 

 room,* where they were suffered to cool undisturbed. 

 Near them on the same table, and at the same height 

 above the table, there was placed another thermometer 

 (suspended in the air to the arm of a stand), by which 

 the temperature of the air of the room was ascertained 

 from time to time. 



No person was permitted to pass through the room 

 while an experiment was going on ; and in order to 

 prevent, as far as it was possible, all those currents of 

 air in the room which were occasioned by partial heat, 

 produced by the light which came in at the windows, 

 the window-shutters were kept constantly shut ; one of 

 them only being opened for a moment, now and then, 

 just to observe the thermometers, and note down the 

 progress of the experiment. 



* This room, which is adjoining to my laboratory, in my house at Munich, is 19 

 feet wide, 24 feet long, and 1 3 feet high. 



