Two meetings of Commission 16 were held. The Commission met also with Commission 22 to confer concerning the advisability of transferring the Physical Observation of Comets to Commission 22. It was decided not to recommend any change.

The Draft Report was amended and approved.

It was voted that the President of the Commission appoint a secretary to circulate information or requests for co-operative work on comets. It was agreed that the President appoint a special committee from the members who are observers of Mars to consult on Martian nomenclature and to report recommendations to the next meeting of the International Astronomical Union.

The report of the President of the Commission was read and accepted without change.

On the motion of Sir Frank Dyson, seconded by Dr W. S. Adams, it was unanimously voted that:

“Commission 17 recommends to the Executive Committee that the list of designations for lunar formations agreed upon by the Commission (item 5 of the President’s report) be printed and that an appropriation not to exceed two hundred pounds be made for the purpose.

Le Président rend hommage à la mémoire de son prédécesseur le Général Ferrié, dont le rôle de premier plan, dans les travaux de la Commission, est présent à tous les esprits, il rappelle aussi le souvenir de M. G. Bigourdan, disparu au cours de l’année. Les éloges de l’un et de l’autre ont été prononcés en séance plénière.

Le Rapport présenté à la Commission des Longitudes par son Président et son Secrétaire a été polycopié, puis distribué avant la séance à tous les membres présents à Cambridge, en même temps qu’un certain nombre de documents annexes. Aussi le Président se contente-t-il de rappeler les points essentiels du document qui traite de l’Opération mondiale des Longitudes à exécuter en octobre-novembre 1933.

Mr Lambert stated that the Committee was a mixed one, the members being appointed by the I.A.U. and by the Association de Géodésie and the present session would be considered as a meeting of the entire Committee.

In connection with Dr Kimura’s report the chairman recommended the resolution passed by the National Committee of Astronomy in Italy and moved that the Union should be asked to grant a small sum of money for the full publication of Kimura’s reductions of the international latitude observations. Mr Bowie suggested that at the present time such action involving expenditure should be delayed. Dr Schlesinger seconded the motion of the chairman and elucidated the Italian proposal. He read a cablegram from Dr Kimura stating the number of pages to be printed and the price. On the basis of these figures it was estimated that the total cost involved would be about five hundred dollars. The motion was carried unanimously.

The President extended a welcome to Dr Kopff who was present at the meeting.

No formal report was presented to the Commission for adoption, but on the suggestion of the President the meeting discussed seriatim various proposals which had been brought forward by members of the Commission and which had been circulated.

(1) A proposal, emanating from Belgium, had been made for an improvement of the present plan for the distribution of observations and computations relating to minor planets and comets, with special reference to those which depart considerably from their ephemerides. The President expressed his opinion that the present arrangements, which were following a natural plan of evolution, were quite satisfactory and should be allowed to continue for some time. Dr Kopff agreed that further organization was at present unnecessary. No motion was taken on this proposal.

The Rev. T. E. R. Phillips submitted a proposal from Commission 16, suggesting that Commission 22 should take from them the subject of comets. After some discussion, in which it was pointed out that, on practical grounds, the methods of observation should outweigh any theoretical considerations in the matter, the following motion was moved by Prof. Öpik, seconded by Prof. Boothroyd, and carried:

“Commission 22 considers that it is not desirable that Comets should be joined to their subject.”

M. le Président rend hommage à ceux de ses membres que la Commission a perdus depuis sa précédente réunion: son eminent Président Turner, le P. Hagen et M. Cosserat.

Il rend succinctement compte de l’état des travaux du Catalogue et de la Carte, et fait ressortir les notables progrès effectués depuis le dernier Rapport.

There were two meetings of the Commission. The first meeting was devoted to an informal discussion of programmes for parallax work. The second session was devoted to a discussion of systematic errors. The President gave a brief summary of the two latest determinations of the systematic errors of trigonometric parallaxes, by Schlesinger (parallaxes published to 1924) and by van Maanen (parallaxes to 1927). Both investigators had used the same basis of comparison, namely, the Mt Wilson spectroscopic parallaxes, and both had made the same fundamental assumption, namely, that the systematic errors of the spectroscopic parallaxes depending on right ascension were negligible.

The Committee expressed its appreciation of the value of the work done by Prof. Seares, while President of the Commission, in the direction of establishing the relations between various other catalogues and the International System.

The relations given by Prof. Seares, in the Draft Report, between the International System and the catalogues that have appeared during the last four years, form a new and very important contribution to this fundamental problem. But nothing in science can be definitive. The formulae given by Seares will be subject to modification by more extended discussion: they must be regarded as provisional; the Committee decided to place them in an appendix to the main report.

It was agreed to send a message of congratulation to Dr R. G. Aitken on the occasion of the completion of the A .D.S., a copy of which was for inspection on the table of the chairman.

Aside from minor alterations and additions which were discussed in reading the Draft Report, the Committee adopted this report as printed and designated a subcommittee for the purpose of working out a short list of double stars situated between + 10° and − 10° declination for the investigation of personal errors. C. P. Olivier, who initiated this proposal, will act as chairman of the sub-committee, which will include R. G. Aitken, H. N. Russell, and G. Van Biesbroeck.

The Draft Report was adopted without modification.

The following resolutions were referred to the General Assembly:

1. 1. The Commission recommends that the yearly subsidy granted by the Union to the Cracow Observatory for the publication of the Ephemerides of Eclipsing Binaries be continued (and increased) to the amount of 1000 gold francs.

2. 2. The Commission suggests that, in view of the urgent need for comparison stars for Variables, more especially those requiring international co-operation, a small sub-committee under Dr Shapley be empowered to canvass the needs of observers and to take steps to encourage systematic work on sequences.

3. 3. The Commission endorses the proposal made by Prof. Grouiller to compile a list of unpublished observations of Variable Stars, and recommends that this compilation be published by the Union.

Dr Lundmark called attention to the deaths of two members of the Commission, Miss Adelaide Ames and Father J. G. Hagen, and of a past member and former chairman, Dr G. Bigourdan, and outlined their contributions to the subject.

The secretary read a letter from the chairman, Dr Hubble, suggesting that the meeting be devoted primarily to informal discussion of relevant problems.

Dr Lundmark, as an introduction, read the recommendations adopted by the Commission in 1928. This was followed by the reading of the first part of the acting chairman’s report on the advance and present state of knowledge of the anagalactic nebulae.

The Commission held two meetings and the time was taken up almost entirely in a discussion of stellar classification.

Dr J. S. Plaskett moved, seconded by Miss Payne, that a sub-committee be appointed to consider the classification of Wolf Rayet and related spectra.

The committee was appointed as follows: Miss C. H. Payne, Prof. H. H. Plaskett, Dr C. S. Beals, Chairman.

Dr W. S. Adams moved, seconded by Dr J. S. Plaskett, that a sub-committee be appointed to tabulate and bring up to date criteria of classification for both high and low dispersion at present in use throughout the stellar sequence.

The committee was appointed as follows: Miss A. J. Cannon, Dr O. Strave, Prof. H. H. Plaskett, Dr B. Lindblad, Dr W. S. Adams, Chairman.

The Report as printed was discussed section by section. Section I being only a summary of progress was, with the correction of a typographical error, accepted.

Section III was discussed and, on the motion of Frost and Moore, a sub-committee was appointed by the Chairman consisting of Adams, Moore and Harper, to prepare a suitable list of standard velocity stars for the faint stars and to revise the previous list of standard velocity stars, omitting those now known or suspected to vary slightly in velocity.

Après avoir rappelé le souvenir du Général Ferrie et de M. Bigourdan, décédés au cours de l’année, le Président met aux vœux l’élection du Vice-Président de la Commission, en remplacement du Général Ferrie. A l’unanimité le Général G. Perrier est élu et il est invité par le Président à prendre place au bureau.

Le Président fait connaître qu’il a examiné les comptes du B.I.H. pour les quatre dernières années et que les règlements ont été respectés:

Les dépenses se sont élevées.

A few questions relating to the observing programme of parallax observers and to catalogues of proper motions for fainter stars were discussed and the following recommendations were passed:

1. (1) “That parallax observers are requested to publish the basis of selection of the stars of their observing programmes.”

2. (2) “That the authors of lists of large proper motions should give more attention to the problem of identifying difficult and interesting stars (for instance by sketches of the surroundings).”

In adopting the Draft Report as drawn up by the President of the Commission the meeting recorded its indebtedness to Dr Spencer Jones for his labour in framing it.

It was resolved to request the executive committee to make a grant of 2500 Swiss francs annually to the Solar Parallax Commission until the next meeting of the Union.

Prof. Kopff regretted that the results of the meridian observations made at Besançon and Rome could not be used in the formation of the Catalogue of Primary Reference Stars as these were received too late for inclusion.

The report of the Chairman was approved and accepted as printed.

On the occasion of the meetings of Commission 12, a joint meeting was held in Cambridge with the Committee on Solar and Terrestrial Relationships. Since the meeting at Leiden the Committee had suffered the heavy loss of two members, Dr L. A. Bauer and General G. Ferrié, whose activity in the Committee had been so great and so highly appreciated. On the termination of the period of office of the Chairman, Prof. Chapman, the International Council of Scientific Unions had nominated Abetti to be Chairman from January 1932.