272 On the AppUcation of Geology to Agriculture. 



an insulated portion of the upper calcareous grit formation, 

 which also produces an excellent tract of land in another part of 

 Yorkshire.-^ 



So also through all the successi^^e divisions of the upper oolitic 

 series, which compose this estate, it was seen that the best upland 

 grass-land was on the peculiar zone or stratum formed on the 

 coralline oolite through all the farms^ though separated from each 

 other by wide intervals. 



We also discovered what, when followed out in other districts, 

 may prove a most valuable fact, that the wheat is usually only 

 thrown out in severe frosts upon those fields formed by this same 

 coralline oolite ; the same cause having no effect upon the adjoin- 

 ing fields, which are on a different stratum, lower in the series, 

 and of a sandy nature, with no calcareous matter in them. A 

 limestone road, as you know, lifts more in frost than a gravel 

 road ; and a different method of planting wheat upon chalk, or 

 other calcareous soils^, must be pursued than that usually adopted, 

 if we wish to secure our wheat crops from failure from this par- 

 ticular cause. 



Next we found (as is the case over an extensive district here) 

 that the entire surface of the portion as yet left out of cultivation 

 upon the estate was formed by the worst beds of the calcareous 

 grit, which (notwithstanding their name) contain no calcareous mat- 

 ter whatever. On analysing three divisions of the calcareous grit 

 rock at Scarborough, I find that the tvvo upper beds are calcareous, 

 the highest of the two in the greatest degree, probably from its 

 vicinity to the coralline oolite, which immediately covers it ; but 

 a lower bed there, like that at Hackness, is entirely destitute 

 of lime. This distinction should be followed out and tested in 

 other districts, as we know that in many places the calcareous 

 grit forms very good land ; probably this arises from the cal- 

 careous beds being there uppermost. Again, when^ on descend- 

 ing the hill-sides, it was found that there were certain fields 

 which, whether towards the south or north, whatever the aspect. 



* I believe I have made one geological mistake in that part of my Letter 

 which alludes to an insulated vein of land upon a high level of very su- 

 perior quality, and which I have named, following Dr. Smith's opinion, 

 upper calcareous grit — the highest formation in the oolitic series, and 

 not very common. Subsequent closer investigation by other geologists, and 

 a discovery of some fresh fossils, makes me now think that the vein in ques- 

 tion is upon the upper good bed of the ordinary calcareous grit, below the 

 coralHne ooUte, and which does not appear elsewhere in the neighbour- 

 hood. Whichever formation, however, of the two it may belong to, the pe- 

 culiarity remains the same. Both strata in other districts form good land. 



I have now no doubt whatever that the soils upon the calcareous grit 

 formation always vary according as__the particular beds of that stratum 

 come uppermost. — January 17, 1840. The Author. 



