716 



SCIENCE 



[N. S. Vol. XLIII. No. 1116 



E. W. Berry and J. A. Gardner, Geological 

 Laboratory, Jolms Hopkins University. 

 The several Upper Cretaceous formations 

 of the Middle Atlantic Coast represent all of 

 the major divisions of the European series. 



17. Upper Cretaceous Floras of the World: 

 Edward W. Berry, Geological Laboratory, 

 Johns Hopkins University. 



The stratigraphic position of the more im- 

 portant of the Upper Cretaceous floras is indi- 

 cated by a diagram. 



18. Observations on Amoeba Feeding on In- 

 fusoria, and their Bearing on the Surface- 

 Tension Theory: S. O. Mast and F. M. 

 EooT, Zoological Laboratory, Johns Hopkins 

 University. 



Surface-tension is probably only a small 

 factor in the process of feeding in Amoeba. 



19. The Electromotive Force produced by the 

 Acceleration of Metals: Eichard C. Tolman 

 and T. Dale Stewart, Department of Chem- 

 istry, University of California. 

 Successful attempts have been made to 



change the relative position of positive and 

 negative electricity in a piece of metal by sub- 

 jecting it to a large retardation. 



Edwin B. Wilson 

 Mass. Institute of Technology, 

 Boston, Mass. 



SPECIAL ARTICLES 



THE KATA THERMOMETER AS A MEASURE OF 

 THE EFFECT OF ATMOSPHERIC CONDI- 

 TIONS UPON BODILY COMFORT 



It has been clearly demonstrated by numer- 

 ous investigations that the objectionable effects 

 of the air of a badly ventilated room are 

 chiefly thermal rather than chemical in nature. 

 At the same time it has been recognized that 

 the ordinary thermometer is a very inadequate 

 measure of the discomfort experienced in such 

 a room because the heat loss from the body 

 surface is influenced not only by the tempera- 

 ture of the surrounding air but also by the 

 humidity present and the radiant heat which 

 reaches the body, and above all by the move- 

 ment of the air. The condition in a close 

 room has been commonly compared with that 

 which obtains outdoors on a muggy day in 



summer; yet it is clear that the outdoor tem- 

 perature must be very much higher than the 

 indoor temperatiire in order to produce a 

 comparable degree of discomfort. 



Dr. W. Heberden^ pointed out these facts 

 nearly a hundred years ago and suggested a 

 way out of the difficulty by the observation of 

 the rate of fall of a thermometer previously 

 heated to a high temperature. He heated a 

 thermometer to 100° F. and noted the num- 

 ber of degrees which it fell in ten minutes as 

 a measure of " sensible cold." He records 

 drops of from 8° to 22° in the first ten minutes. 



The same device has recently been inde- 

 pendently worked out by Dr. Leonard Hill in 

 England- and the apparatus is now sold by 

 Siebe Gorman and Company of Chicago under 

 the name of the Kata thermometer. 



The Kata thermometer outfit consists of two 

 specially constructed thermometers with large 

 bulbs and stems graduated from 86° to 110° F., 

 one to be used as a dry and the other as a wet 

 bulb thermometer. The bulbs are heated to 

 about 110° and then placed in clips which 

 hold them in a horizontal position, after dry- 

 ing the bare bulb on a clean cloth and jerking 

 excess moisture off the silk covered one. The 

 time taken to fall from 100° to 90° is then 

 noted, best by the use of a stop-watch. 



The rate of fall of both thermometers will 

 obviously be affected by air movement and 

 radiant heat as well as by air temperature, and 

 that of the wet bulb by the humidity of the 

 air as well. Dr. Hill believes that the com- 

 bined influence of these factors will affect the 

 Kata thermometers very much as it does the 

 human body, and suggests a one-minute pe- 

 riod for the wet bulb and a three-minute pe- 

 riod for the dry bulb as upper limits for com- 

 fortable atmospheric conditions. 



This instrmnent promises to be of so much 

 assistance in the practical study of ventilation 



1 ' ' An Account of the Heat "of July, 1825 ; to- 

 gether with Some Eemarks upon Sensible Cold," 

 Trans. Eoy. Soc, London, 1826, Part II., p. 69. 



2 ' ' The Physiology of the Open-Air Treat- 

 ment," The Lancet, OLXXXIV., May 10, 1913, p. 

 1,283; see also O. W. Griffith, "Ventilation and 

 Housing, ' ' The Medical Officer, XIII., June 19, 

 1915, p. 273. 



