416 Prof. G. H. Stone—Stones of the Salt Range. 
During the discussion that ensued, the question was considered 
whether the stones had received their shapes from the action of wind- 
blown sand. Having made a special study of sand-carving in a 
favourable region, the writer became interested in the subject, and 
with a view to compare the Punjab stones with the sand-facetted rock- 
fragments so common in various parts of America, wrote to Dr. Blan- 
ford in order to obtain specimens of the stones in question. By the 
kindness of Dr. Blanford and Mr. Wynne, plaster casts of both the 
specimens described by them have been sent to me. Dr. Blanford 
also put me into communication with Dr. Henry Warth, who has 
kindly sent me three of the scratched stones which he had found in 
the field. It is the object of the present paper not to enter upon the 
large question of a Glacial period in Paleozoic or Mesozoic time, 
but briefly to consider the testimony of the specimens about to be 
described as to their own origin. Most of the conclusions arrived 
at have been anticipated by those who have discussed the origin of 
the shapes of these particular specimens.’ 
Yet conclusions drawn from observations made in widely removed 
regions have a comparative value; therefore, at the risk of repeating 
what has been observed elsewhere, the facts are here recorded which, 
observed in Colorado and Maine, throw light on the origin of the 
markings on the stones in question. The existence of a Glacial 
period can only be proved by the whole mass of field evidence, and 
this can only be worked out by the geologists on the ground. In 
solving the general problem it will be necessary first of all to deter- 
mine the manner in which the stones and boulders were facetted and 
scratched. Afterwards comes the question how they were brought 
to their present positions in the midst of clay or sand. LHvidently 
a study of the markings on the stones can afford little direct evidence 
except on the first of these questions. 
The specimens in my possession are the following. 
No. 1. This is a plaster cast of the stone exhibited before the 
British Association by Mr. Wynne. The form is not that which 
would be caused by the wind. 
No. 2. A plaster cast of the stone described by Dr. Blanford. 
The cast, Dr. Blanford informs me by letter, does not show the 
scratches as plainly as the original. Yet the scratches on the facets 
are so readily distinguished that a friend, a mining engineer, who 
happened to be present when the cast was received, at once exclaimed: 
“« Why it looks as if it had been in a Mexican arastra.”’ The scratches 
are not such as could be produced by blowing sand or gravel. 
No. 3. Forwarded to me from Stuttgart by direction of Dr. Warth. 
It is composed of a dark red felsitic ground-mass, containing many 
crystals and grains of a lighter red felspar, with some free quartz 
and small quantities of one or more accessory minerals. All fracture 
surfaces of the stone are quite uneven. On breaking off a portion 
1 Including in addition to the original articles of Dr. Blanford and Mr. Wynne, 
communications by Mr. R. D. Oldham, Grou. Mae. Jan. 1887, and from Rev. A. 
Irving, Grou. Mac. April, 1887. Similar specimens are discussed by Dr. H. Warth, 
Records Geol. Survey of India, vol. xxi, pt. 1, 1888. 
