Phoenix weekly herald., 1897-12-23
ARIZONA CLIMATE.
The Temperature of the Atmosphere
 and the Thermometer

and the Thermometer.
 MT. W. T. Blythe. Observer of the
 Signal Service office in this city, issues
 monthly bulletineS of more than or
 dinary interest in this connection In
 his last bulletin he takes up the matter
 of Temperature" on which subject
 he says in part:
 It is q noticeable fact that nOtwith- standing the popular opinion prevailed
 during the heated term, and is almost universally expressed now since it has passed. that the summer was unusual ! ly pleasant. or at least that much less than the usual discomfOrC on account of heat was experienced, the monthly
 mean temperature for the Territory for each month, from April to Septem- l Der inclusive. was above the normal. | The average monthly excess for the six months was 2.9 degrees.
 The continuously excessive high l temperatures. which usually prevail during the summer season on the des- ert plains and in the great valleys of | the Colorado, Gila and Salt rivers, and ill the smaller valleys of greater ele- vatiOn above sea level. but low as compared with the mountains in their vicinity, which, when accompanied l by correspondingly high minimum or night temperatures, produce an accu-
 
 sleeping in doors in comfort is well nigh impossible. did not begin during the summer of 1897 until the latter part of June.
 The period of extreme heat. as above described. lasted in the districts nam ed through July and August It waS of course, preceded and followed by shorter periods of one or more days in some localities; but these periods of F,i, short duration. that, being co-eXistent with extreme dryness and clear skies, conditions most favora ble for rapid evaporation and rapid radiation and consequently low temperatures at night, the most, if not the only discom- fort experienced was caused by the great variation.
 That the degree of temperature eX- pressed by the reading of the dry bulb thermometer is greater than the sensible temperature whenever there 1 iS q difference between the dry and l wet bulb thermometer readings, is gen l orally conceded. But just what frac- l ton of the difference between the dry | and wet bulb thermometer readings l should be taken to note the degree of 1 temperature felt has not been deter mined, and from the nature of the | question, since it involves conSidera l
  of person, etc. of the indi- vidual eXperimented upon, a combin- alton of conditions that cannot be eX- actly the same in any two. let alone all all persons, never can be more than appr0Ximated.
 After considerable study of the sub ject as enunciated in the writings and l of others. and from a per sOnal experience acquired during sev-
 
 Bureau in localities differing redically 1 in temperature and moisture; the writers conclusion is that three-fifths of the difference between the dry and wet bulb thermometer readings. de lucted from the reading of the dry bulb, expresses approximately the legree of temperature felt by the aver lge person.
 Comparison of Temperature.
 Adopting the foregoing assumption we are prepared to compare the tenn )eratures--;Is published i'll the Month y Weather Review-at one place with ! hat of another; that of Arizona with hat of the States in the Mississippi alley,Of that of Phoenix with that at | St. LOuiS Thus. the mean dry bulb thermometer readings at St Louis for August. 1897, was 76.S, the mean of the 1 mean of the wet bulb readings was ' 'O-U. tuIefence Ip-o. WHICH, dcOfulIlS O the above hypothesis. would give ' he sensible temperature 10.3 degrees The mean dry bulb temperature at 'hOeniX for the same period was S9.2. he mean of the wet bulb readings vas roo, difference 19.2, and the sen ible temperature IT., or q difference | n the temperature as is felt, at the ! ! we places. by the average person. of | degrees instead of 12.4 degrees, as hown by the usual method of compar- lg temperatures:i e, without taking ; lto consideration the evapOrating and consequently cooling capacity of the ir at one place as compared with that :, t the other