and its Physical Relations to the Glacial Epoch. 



121 



Table {continued). 



I. 



II. 



in. 



IV. 



Number 



v. 



Number of 



VI. 



VII. 



Midwinter tem- 

 perature of the 



Number 

 of years 

 before 



Excentri- 



Longitude 

 of perihe- 



of days 

 by which 

 the winter 



degrees by 

 which the 

 midwinter 



Midwinter 

 tempera- 

 ture of the 



centre of Scot- 

 and, on the sup- 

 position that the 

 Gulf-stream was 

 affected by 

 change of ex- 



epoch 

 1800. 



city. 



lion. 



was longer 

 than the 

 summer. 



tempera- 

 ture was 

 lowered. 



centre of 

 Seotland. 















centricity. 



250,000 



00258 



59 39 





o 



O 



- 



240,000 



0-0374 



74 58 



17-41 



28-3 



10-7 



1-5 



*230,000 



00477 



102 49 



22-22 



320 



7 



- 3-3 



*220,000 



0-0497 



124 33 



23- 15 



341 



4-9 



- 6 



*2 10,000 



00575 



144 55 



26-77 



37-7 



1-3 



-106 



200,000 



00569 



168 18 



26-49 



37-4 



1-6 



-10-2 



* 190,000 



00532 



190 4 



24-73 



35-7 



3-3 



- 8 



*180,000 



00476 



209 22 



2213 



331 



5-9 



- 4-7 



*170,000 



00437 



228 7 



2036 



31-3 



77 



- 2-4 



160,000 

 150,000 



00364 



236 38 



1692 



27-8 



11-2 



21 



00332 



242 56 



15-44 



26-2 



12-8 



4-2 



140,000 



00346 



246 29 



16 09 



.26-9 



121 



3-3 



130,000 



0-0384 



259 34 



17-80 



28-8 



10-2 



0-8 



120,000 



00431 



274 47 



2009 



310 



8 



- 2 



tl 10,000 



0.0460 



293 48 



21-38 



32-4 



66 



- 3- 



100,000 



0-0473 



316 18 



2203 



330 



6 



- 4-6 



t 90,000 



00452 



340 2 



2101 



320 



7 



- 3-2 



t 80,000 



00398 



4 13 



18-45 



29-4 



9-6 







t 70,000 



00316 



27 22 



14-69 



25-5 



13-5 



5-1 



t 60,000 



0-0218 



46 8 











50,000 



00131 



50 3 











t 40,000 



0-0109 



28 36+ 











t 30,000 



00151 



5 50} 











t 20,000 



0-0188 



44 











t 10,000 



00187 



78 28 















0-0168 



99 30 











The excentricity and longitude of the perihelion at the periods marked thus (*) 

 were calculated by Mr. Stone of Greenwich Observatory, and those marked (t) 

 were calculated by M. Leverrier. 



It will be seen that at the periods marked thus (j) the perihelion has a retrograde 

 motion. It will also be observed that at those periods the excentricity was at a 

 minimum. 



Column VI. gives the midwinter temperature of our island. 

 It is found by subtracting the numbers in column V. from 39°, 

 the present midwinter temperature. 



It has been shown (see Phil. Mag. for August 1864, and 

 ' Reader/ December 2nd and 9th, 1865) that when the excen- 

 tricity reaches a high value, and one of the solstice-points is in 

 perihelion, the difference between the temperature of the two 

 hemispheres must be very great. The hemisphere which has its 

 winter in aphelion and under a condition of glaciation, is much 



