cnAP. XIX. 



TEiMPERATURES ON SUMMITS. 



345 



In Appendix E. a few remarks are made upon Temperatures in 

 Ecuador, and I refer here only to those which were experienced on 

 Summits. If there had been a constant diminution of 1° Faht. for 

 every 300 feet of ascent from the level of the sea, temperatures at 

 the tops even of the lowest of the peaks we ascended would always 



Date. 



Mountain. 



Height in 

 Feet. 



Temperature 

 on Summit. 



Temperature at 

 Guayaquil. 



1880 



Jan. 4(5.15p.m) . 



Chimborazo 



20,498 



Faht. 

 2V 



Faht. 

 85° ( 6 p.m.) 



Feb. 2(1.15 „ ) . . 



Corazon 



15,871 



37° -43° 



79° (11 a.m.) 



„ 18 (6.20 a.m.) . . 



Cotopaxi 



19,613 



21° 



82° ( ,. ) 



Mar. 10 (10-11.40 a.m.) 



Antisana 



19,335 



44° -60° 



80° ( ., ) 



„ 23 (11.15 a.m.) 



Pichincha . 



15,918 



46° 



80° ( ., ) 



April 4(10.45-11 a.m.) 



Cayambe 



19,186 



32° -41° 



79° ( ., ) 



„ 17 (1.30-2.40 p.m.) 



Sara-urcu . 



15,502 



43°-5-55° 



80° ( ,. ) 



,, 24 (12 noon) . 



Cotocachi 



16,301 



36^ 



81° ( ,. ) 



June 29 (11-11.15 a.m.) 



Carihuairazo 



16,515 



38° -42° 



74° ( .. ) 



July 3 (1.40-2 p.m.) . 



Chimborazo 



20,498 



15° -20° 



74° ( ., ) 



have been found well below the freezing-point. The above Table 

 of Temperatures, ^in the shade/ shews those which were actually 

 experienced. 



previously lost. Minus index-errors are sometimes lessened, and plus index-errors 

 are sometimes increased. The recovery is gradual, and commonly extends over a 

 greater length of time than the period during which diminished pressure has been 

 experienced. In aneroids which have been kept at diminished pressures for a con- 

 siderable space of time [a week or upwards] the most important part of the amount 

 that will be recovered will be regained in the first week. The greater part of the 

 recovery of the first week is usually accomplished in the first day. The recovery in 

 the first hour is almost always larger than that in any subsequent hour. 



3. The errors which will probably be exhibited by aneroids during natural varia- 

 tions of pressure may be learned approximately b}' submitting them to artificially- 

 produced variations of pressure ; but the one-hour test which has heretofore been 

 commonly applied for 'verification ' is of little value except for determining errors 

 of graduation, and the errors which will be exhibited at similar pressures in a aimilar 

 length of time. 



4. Comparisons of travellers' aneroids against the mercurial barometer at natural 

 pressure, upon return to the level of the sea, after prolonged journeys in elevated 

 regions, have not the value which is at present assigned to them. 



5. Large reductions will have to be made in the heights of many positions which 

 have been determined by aneroids. 



2 Y 



