398 REPORT—1899. 
Erratic Blocks of the British Isles.—Report of the Committee, consist- 
ing of Professor E. Hutu (Chairman), Mr. P. F. KENDALL 
(Secretary), Professor T. G. Bonney, Mr. C. E. De Rance, Pro- 
fessor W. J. Sotuas, Mr. R. H. TrppemMan, Rev. S. N. Harrison, 
Mr. J. Horne, Mr. F. M. Burton, Mr. J. Lomas, Mr. A. R. 
DwerryHouse, Mr. J. W. StatHer, and Mr. W. T. TUCKER, 
appointed to investigate the Erratic Blocks of the British Isles, 
and to take measures for their preservation. (Drawn up by the 
Secretary.) 
Tue attention of the Committee has been concentrated mainly upon the 
erratics of Yorkshire, and they have again to acknowledge the great 
services rendered by the Yorkshire Boulder Committee, and the sub- 
sidiary organisation working on the eastern side of the county under the 
auspices of the Hull Geological Society. 
Of the value of their work it would be difficult to speak too highly, 
especially when it is borne in mind that it is not a new-born zeal which 
animates the workers, but that year by year they have devoted themselves _ 
to the task, and now enter upon the second decade. 
The most noteworthy new facts relate to the dispersal of erratics of 
Scandinavian origin, which have now been traced over a much wider area 
and to much greater altitudes than previously ; moreover, the distribution 
of type sets of rocks from the east coast of Norway amongst the active 
workers has given them a firmer basis upon which to work, and several of 
the rocks have now been recognised in the drift of Yorkshire. . 
The new records of Scandinavian rocks enlarge our knowledge of their 
dispersal in two important particulars : their horizontal range has been 
much extended, and they have been traced to altitudes far exceeding that 
previously ascribed to them. The discovery of Norwegian rocks to the 
westward of the Chalk Wolds announced in the report presented last year 
has been supplemented by two new records at Brantingham Thorp and 
Elloughton respectively. 
The well-known Rhomb-porphyry has been found by Mr. J. W. 
Stather at Speeton at an altitude of 400 feet above Ordnance Datum, by 
Messrs. Kendall and Muff at altitudes exceeding 600 feet at several points 
on the northern slopes of the Cleveland Hills, but the greatest height to 
which this rock has been traced in Britain is indicated by Mr. Stather’s 
discovery of a specimen embedded in Boulder-clay at 810 feet Ordnance 
Datum on West Rigg in the Lockwood Hills. 
Some interesting facts have been brought to light on the Cleveland 
Hills, where Messrs. Kendall and Muff have found that at high altitudes 
there is a significant absence of the rocks which belong to the Teesdale 
dispersion, such as Shap granite, Brockram, and Whin sill, while all Car- 
boniferous rocks are exceedingly rare ; while, on the other hand, Magnesian 
Limestone of a type which appears to be restricted to the coast of Durham 
is very abundant in association with a profusion of porphyrites from the 
Cheviots, and occasional flints, Scandinavian rocks and shell fragments. 
An important aid to the elucidation of the origin of the erratics of the 
