oe 
ON PARACHORS—PHOTOGRAPHS OF GEOLOGICAL INTEREST. 26] 
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Parachors.—Report of Committee (Dr. N. V. Sipawick, Chairman; Dr. 
8. SuepEN, Secretary; Dr. N. K. Apam) appointed to collect. and 
tabulate all available data on the Parachors of Chemical Compounds 
with a view to their subsequent publication. 
Tar Committee met in November 1930 to consider the arrangement of the list of 
parachors. It was decided that compounds containing carbon should be listed in the 
order used in Richter’s ‘ Lexikon,’ and that inorganic compounds should be arranged 
in alphabetical order of their symbols. The preparation of the list in card index form 
was left in the hands of the Secretary. 
The card index is now almost complete and contains entries for more than 500 
substances. A number of references have, however, to be verified before the list will 
be ready for typing. 
No expenditure has yet been incurred; the chief cost will be the typing of the 
list from the card index. It is requested that the grant be carried over for another 
year to cover this expense and enable the list to be brought into a form suitable for 
publication. 
'__ During the year a list of parachors has appeared in Landolt-Bornstein (Physikalisch- 
Chemische Tabellen, 5th ed., 2nd supplementary volume, part 1, pp. 172-188). This 
list is arranged in groups of chemically similar substances ; it is by no means complete 
and contains a number of errors, hence it cannot replace the proposed B.A. list. 
Photographs of Geological Interest. — Twenty-sixth Report of 
the Committee (Professors E. J. Garwoop, Chairman, and 8. H. 
Reynotps, Secretary; Messrs. E. G. W. Exuiorr, J. F. Jackson 
and J. Ranson, Professor W. W. Warts and Mr. R. J. Weucu.) 
In the present report 121 photographs are listed, bringing the number in the collection 
to 8,403. A further series of 11 prints comes from the Reader series, 1,144 photographs 
having been added to the collection from this source. 
The present series includes an excellent set from Cornwall contributed by Mr. E. 
Jones, a series illustrating washouts in the Chalk of Kent from Mr. A. L. Leach, 
. others from Herefordshire and Pembrokeshire contributed by Mr. G. Macdonald 
Davies, from Antrim sent by Mr. A. R. Dwerryhouse, from Cardigan by Mr. J. 
Challinor, and from Somerset by Dr. F. B. A. Welch. Miss Spencer has kindly 
presented some remarkable photographs of 100- and 200-ton blocks of concrete 
shifted by the sea at Holyhead, these having been taken by the late H. E. Spencer. 
The Hon. Secretary contributes sets from Dorset and Cattybrook, near Bristol. 
The new series of geological photographs the publication of which has been in 
_ preparation for some years, is now ready. Application should be made to the Hon. 
_ Secretary for information. 
The Reader negatives being the property of the Committee, prints (}-plate) may 
be obtained through the Hon. Sec. at 4d. each, lantern slides at 1s. 
The Committee recommend that they be reappointed. 
TWENTY-sIxTH List or GEOLOGICAL PHOTOGRAPHS. 
From Aveust 1, 1930, ro Juny 1, 1931. 
List of the geological photographs received and registered by the Secretary of 
the Committee since the publication of the last report. 
Contributors are asked to affix the registered numbers, as given below, to their 
negatives, for convenience of future reference. Their own numbers are added in 
order to enable them to do so. Copies of photographs desired can, in most instances, 
be obtained from the photographer direct. The cost at which copies may be obtained 
_ depends on the size of the print and on local circumstances over which the Committee 
have no control. 
The Committee do not assume the copyright of any photograph included in this 
list. Inquiries respecting photographs, and applications for permission to reproduce 
them, should be addressed to the photographers direct. 
Copies of photographs should be sent, unmounted, to 
Professor 8. H. Rrynowps, 
The University, Bristol, 
