Page:On the Influence of Carbonic Acid in the Air upon the Temperature of the Ground.pdf/40

against the theory, because it becomes more and more impossible to reconcile the chronology demanded by Croll's hypothesis with the facts of observation.

I trust that after what has been said the theory proposed in the foregoing pages will prove useful in explaining some points in geological climatology which have hitherto proved most difficult to interpret.

---

Addendum^[1].

As the nebulosity is very different in different latitudes, and also different over the sea and over the continents, it is evident that the influence of a variation in the carbonic acid of the air will be somewhat different from that calculated above, where it is assumed that the nebulosity is the same over the whole globe. I have therefore estimated the nebulosity at different latitudes with the help of the chart published by Teisserenc de Bort, and calculated the following table for

Latitude.	Nebulosity.		Conti­nent per cent.	Reduction factor			${\text{K}}=0.67$.		${\text{K}}=1.5$.
	Conti­nent.	Ocean.		Conti­nent.	Ocean.	Mean.	Conti­nent.	Ocean.	Conti­nent.	Ocean.
-70
	58.1	66.7	72.1	0.899	0.775	0.864	-2.8	-2.4	3.1	2.7
-60
	56.3	67.6	55.8	0.924	0.763	0.853	-3.0	-2.4	3.3	2.7
-50
	45.7	63.3	52.9	1.057	0.813	0.942	-3.5	-2.7	3.8	2.9
-40
	36.5	52.5	42.9	1.177	0.939	1.041	-3.9	-3.1	4.1	3.3
-30
	28.5	47.2	38.8	1.296	1.009	1.120	-4.1	-3.2	4.5	3.5
-20
	28.5	47.0	24.2	1.308	1.017	1.087	-4.1	-3.2	4.3	3.4
-10
	50.1	56.7	23.3	1.031	0.903	0.933	-3.1	-2.7	3.3	2.9
-00
	54.8	59.7	24.2	0.970	0.867	0.892	-2.9	-2.6	3.1	2.8
-10
	47.8	54.0	22.5	1.056	0.932	0.960	-3.3	-2.9	3.4	3.0
-20
	29.6	49.6	23.3	1.279	0.979	0.972	-4.1	-3.1	4.2	3.2
-30
	38.9	51.0	12.5	1.152	0.958	0.982	-3.8	-3.2	4.0	3.4
-40
	62.0	61.1	00.9	0.749	0.719	0.719	-2.9	-2.8	3.2	3.1
-50
	71.0	71.5	00.9	0.749	0.719	0.719
-60

1. Cf. p. 265.