TRANSACTIONS OF THE SECTIONS. 
69 
|b the margin are tables showing the number of regiments, their strength, place of 
^.the number ofdavs it will require to have them assembled at any given point, 
b; is fact the whole exhibits the organization of the naval and military forces of 
«two countries. , ^ • 
Sa6. Map of the Watercounes rif Sweden (/toulh aiid middle part).—On ihts map 
^ the fulminating ridges are shown, iind how the watercourses (or rather in what 
itoion the waters) luke ilieir course in consequence. .re? r 
Gateral Alap of Scandinavia.—TUh map comprises the whole of Scandi- 
•nij&nniarlt, Sweden, and Noi-way, with the exception of the northernmost part. 
fJstbiiinapthe different railroads which are in contemplation to be made in 
heku are marked with a red line. _ 
On a System of Colour for all Geological Majis. 
By J. W. Salter, F.G.S.., AJj.S. 
IW tDlTeronces of principle, as to the colouring of geological mnp8,wdjich exist be- 
^ifieirmious authors, render the comparison ol diaiinct areas difficult, and will 
•^preseiU obstacles in Uic wav of generalization, vvliile such various nicUiods e-xist. 
Tm ohject of this comimioica’tion U to propose one uniform scale of colounng 
^Mctooll districts,-by adopting as its basis the prUmatic speciriim. Uie 
•ntittijeof adopting such h (.tundard is obvious, since it is acknowlcngea by all 
5"*^ men of whatever country : and it fortunately oflers os a sufficient oumber 
“iuinct colours, yet graduated and harmonized with e.'«ch other, for all the chief 
F^nfstrata acknowledged by geologists. 
Joe jrismaiic spectrum of Newton, as seen in the lower arch of the rambow, con- 
• rf jcvun colours, and these it is proposed to apply in the tuinexed diagram to 
wjcniogical scale. The older and obscurer strata seem most naturally to here- 
»»eMeiibyihedull and darker end of the spectrum, and the brighter ones will 
the approach to the modern period. The annexed divisions are not strictly 
web geologist must admit, but the upward or downward extension of any one 
not affect the general principle. 
^. 'r-...:--.. Indigo.Lower PaltEozoic, 
Silurian andCam- 
brian. 
Violet.Hypozoie or Azoic 
stratified rocks. 
Dark-red, spotted 
or striped with 
different colours, Igneous and intru¬ 
sive rocks. 
..Tertiary. 
»■•••. .Cretaceous. 
. n„i!.i.. 
p .Oolitic. 
r . 
.. • -Upper Palicozoic,in¬ 
cluding Pernmui, 
Carboniferous and 
Devonian. 
of the above colours maybe divided to express the component strata of eadi 
^Koburine the lower divisions light red, yellow, blue. &c., increasing the 
2iyonhe middle division, and giving lo the tlrird or uppermost 
succeeding colour; or if furtlier subdivision be attempted by colour, 
shades mav be varied ad libitum by the admixture m various propor- 
binary colou'r which is complementary to it. Thus the three shades of 
^ wch be varied and divideil into bands by varieties of 
>ts complementary purple, blue by orange, &c., as m the annexed 
Subdivisions. 
Varied by 
Yellow with a 
Shades of 
dash of red. 
Brown. 
Strong yellow. 
Of Olive. 
Pale yellow. 
Of Gray. 
» a difficulty attending the introduction of the present scheme of colours. 
