At the Cambridge meeting in 1932 the following resolutions of Commission 3 were adopted by the Union:

1. 1. Que l’équinoxe de 1900.0 soit adopté pour tous catalogues qui ne sont pas catalogues de précision et que quand on désirera plus tard de changer l’équinoxe celui de 2000.0 soit adopté.

2. 2. Que les abréviations (à 4 lettres) des noms des astérismes qui se trouvent dans le Catalogue of Bright Stars (Schlesinger) soient approuvées à l’exception de cinq astérismes qui seront représentés par Arie, Cane, Dlph, Tria, Tr Au (v. Trans. LA.U. 4, 221, 1932).

3. 3. Que la Commission favorise l’établissement d’une notation uniforme dans l’astronomie, à moins qu’il n’y ait pas de conflit avec de notations semblables dans les sciences alliées.

With the publication of the volume Délimitation Scientifique des Constellations and the Atlas Céleste, and the adoption of standard sets of three-letter abbreviations (Rome 1922) and four-letter abbreviations (Cambridge 1932) for the constellations, important work was brought to a close. The main task now before Commission 3 appears to be the working out and publication of a set of notations covering the whole field of astronomy.

At the 1932 meeting three proposals before the Commission were referred to the directors of the national ephemerides (Trans. I.A.U. 4, 222, 282).

1. (1) That the equation of time be given with the same sign in all almanacs.

2. (2) The question of duplicate printing.

3. (3) The possibility of adopting a uniform system for star positions.

Although the directors have discussed these by correspondence, they wish to take the opportunity of verbal discussion in Paris before presenting their final report. The proposal that duplicate printing of apparent places of stars should be eliminated has been favourably received. A joint meeting with Commission 8 is being arranged for the purpose of discussing the selection and positions of future fundamental stars; at present the general trend of opinion favours the adoption of the FK3 of the Berliner Jahrbuch.

M. Mascari a adressé, en vue des assemblées de Leyde (1928) et de Cambridge (Mass.) en 1932, un long rapport contenant les abréviations méthodiques (Transactions of the I. U.A . 3, pp. 19-39 et 4, pp. 21-2). M. Mascari a eu le regret de constater que beaucoup trop souvent, les auteurs ne font pas le plus léger effort pour lutter contre leurs habitudes et se soumettre à une discipline étroite.

M. Grouiller suggère que l’Union publie une liste des abréviations concernant les publications astronomiques proprement dites; quant à celles qui ne renferment que très occasionnellement de l’astronomie, on pourrait toujours rétablir les abréviations en se servant des listes d’abréviations générales déjà publiées par l’Union transactions of the I.U.A. 3, pp. 34-7). En ce qui concerne la bibliographie mensuelle, dirigée actuellement par M. le Comte de la Baume-Pluvinel, M. Grouiller est d’avis que la Commission adopte une motion d’approbation telle que la suivante: “La Commission a appris avec satisfaction la réunion en un seul organe des publications bibliographiques assurées par la Société astronomique de France et l’Association française d’observateurs d’étoiles variables. Elle recommande la continuation de cette publication contrôlée par une commission spéciale représentant ces deux Sociétés.”

From June 4,1932 (date of the last report) up to the present date the Bureau has distributed 452 telegrams and published 153 circulars (Nos. 382-534).

Again the Bureau has been supported by a great many colleagues and institutions.

As heretofore, the leading principle in our work has been as far as possible to procure provisional data for the continuous observation of new objects. Following this line the telegraphic service has been used when necessary to safeguard new discoveries, while in all cases possible the circulars have been depended on. Thus, as before, in dubious cases we have, to begin with, sent a telegram to a few correspondents only, asking for control. In cases of rediscovery of periodic comets and in other cases, when there was no risk of losing the object, we have distributed the announcement through the circulars.

Since the last meeting of the Union, Sir Frank Dyson, who for forty years had devoted himself to the advancement of meridian astronomy, has resigned the position of president of the Commission. The Executive Committee have done me the honour of inviting me to fill the vacancy.

I have sent a circular letter to all members of the Commission asking for a report on the meridian astronomy being carried on in the institutions with which they are connected, and for suggestions of subjects which might be discussed in Paris. In some countries, particularly Germany and U.S.S.R., there are a number of observatories carrying on meridian astronomy but not represented on the Commission, and I have asked the representatives of these countries to send me details of the work of the various institutions in their countries. The following report is largely based on the replies I have received.

La Commission n’a pas été informée de travaux particuliers importants concernant les matières d’optique. Il convient toutefois de mentionner dans cet ordre d’idées les résultats intéressants obtenus par application d’une pellicule d’aluminium comme surface réfléchissante, pour les miroirs astronomiques.

Le dépôt est fait par évaporation dans le vide et s’applique immédiatement aux miroirs en verre de petites dimensions. Pour les grandes surfaces, l’installation capable de résister à la pression atmosphérique peut présenter de grandes difficultés. Cependant, il a été possible de traiter ainsi, par exemple, le miroir de 90 cm. de diamètre de l’Observatoire de Lick. Plusieurs observatoires américains ont mis en service des miroirs aluminisés.

Mr Royds writes: “The original scheme for daily character figures called for integers ranging from 0—5 to characterise the solar activity for bright and dark flocculi. Since then it has appeared to some observatories to be desirable, particularly as the spot cycle has approached its minimum, to quote character figures intermediate between whole integers. Many observatories have introduced 0.5, 1.5, 2.5, etc., in addition to whole integers, whilst others have also used 0.2, 0.7, 1.2, etc. It seems to me that sufficient experience has now been gained to decide how far this subdivision between whole integers is to be carried. Kodaikanal would be willing to revert to the original proposal of whole integers on the scale 0.5. If it is considered desirable to interpolate half integers, I suggest that whole integers on the scale 0-10 would be easier to print and to read.”

Au cours des trois années 1932,1933 et 1934, les relevés et statistiques habituels des flocculi, des protubérances et de l’épaisseur de la chromosphère, ont été poursuivis et publiés régulièrement. Ils se répartissent de la manière suivante:

The majority of the members of the Commission have been good enough to send in full reports regarding subjects of interest to this Commission. Extracts from them relating to questions which may be the subject of useful discussion at the forthcoming meeting in Paris are given below; references to research undertaken during the last three years, particulars of which are readily available in recent astronomical publications, are omitted.

(i) 1936, June 19. The Eclipse Committees of Japan and the U.S.S.R. have been making preliminary meteorological studies of the weather conditions along the belt of totality in their respective countries. The Japanese Committee report (Bulldin, Kwasan Observatory, 283, 1934) that, while at the extreme east and west of their totality zone the weather prospects are unfavourable, for the central part, along the north-east coast of the island of Hokkaido, from Esasi to Monpetu and in a region round Syari the weather conditions are as good as in the best seasons of Tokyo and Kyoto in an ordinary year. A pamphlet giving all information is being prepared and will shortly be circulated in astronomical circles, but it may be mentioned that Monpetu and Syari are accessible by rail from the port of Otaru. There is electric current, 100 V, A.c., labour is readily available and accommodation will be possible for small parties.

The 1932 report of this Commission, and the report of the ensuing discussion, revealed an unsatisfactory position with regard to sources of the red line of cadmium which could be relied upon to give the adopted standard value for the wave-length 6438.4696 x 10−10 metre.

Dr Meggers has summarised the position very clearly in a recent paper on “ Interference Measurements in the Spectra of Noble Gases” (B.S.J. Research, 13, 293, 1934) and has expressed a strong preference for the specification of the Michelson lamp adopted in 1927 by the International Conference of Weights and Measures (see Trans I.A.U. 4, 58, 1932). He points out that the I.A.U. specification of 1925 is less restricted, inasmuch as it does not exclude high-frequency excitation and makes no mention of the volume or capillary bore of the tube, but requires that it must give interferences with differences of path of at least 200,000 waves. The last condition is considered objectionable on the ground that this is less than half of the theoretical or actual limit of the Michelson tube, and it is further considered that cadmium sources in which any such reduction in interference order occurs will certainly yield a different value for the primary standard.

The following work embodying researches coming within the scope of this commission has been published since the last meeting of the Union: La Planète Mercure et la Rotation des Satellites, by E. M. Antoniadi; Gauthier-Villars, Paris.

In addition to references to the work of other astronomers the author gives a summary of his own observations with the 0.83 m. refractor at Meudon and his conclusions.

The following Memoirs or papers not specifically referred to in the body of the Report have also been published since the last meeting of the Union: Cometa Halley. Vol. xxv of Resultados del Observatorio Nacional Argentino. This is a monograph on the Comet at its 1910 return. By C. D. Perrine. Les Comètes en 1930,1931 et 1932. By F. Baldet. (L’ Astronomie 46,497 et 48,175.) I Fondamenti Psicologici dell’ Indagine Visuale. By M. Maggini. (Memorie dellaSoc. Astron. Italiana, Vol. VIII, 2.) Théorie Photométrique des Eclipses de Lune. By F. M. Link. (Bulletin Astronomique,

8 fase. 11.) Relative Lunar Heights and Topography by means of the Motion Picture Negative.

At the meeting of the Commission in 1932 under the Presidency of Prof. E. W. Brown, it was resolved that the “Named Lunar Formations” presented in manuscript by Miss Blagg and Dr Müller should be printed and published. It is anticipated that the volume will be distributed before the meeting of the I.A.U. in Paris.

The reference maps prepared by Mr Wesley and Miss Blagg were not recommended for immediate publication. It was thought that they might be incorporated with the series of photographic maps in preparation by the Committee of the Carnegie Institution of Washington on Study of the Surface Features of the Moon. After correspondence with Dr Wright, however, it seemed better that the maps accompanying the “Named Lunar Formations” should be published with them. The Commission again expresses its great indebtedness to Miss Blagg and Dr Müller for their arduous and painstaking labour.

Trois résolutions ont été adoptées par la 4e Assemblée générale de l’Union astronomique internationale, à Cambridge (Mass.) en 1932.

Elles se rapportaient à l’opération internationale des longitudes (réalisée en 1933) et avaient pour objet:

1. (1) L’émission d’un trait d’une durée de 10 secondes après tout envoi de signaux horaires.

2. (2) La mission confiée au Bureau international de l’Heure (B.I.H.) de centraliser, discuter et publier les résultats de l’opération.

3. (3) L’approbation du programme des opérations, exposé dans le Rapport présenté à Cambridge par le Président et le Secrétaire de la Commission.

Le Président est heureux de constater que les propositions de ce Rapport ont pu être réalisées dans une très large part. Il remercie tous les Observatoires et organismes participants de leur collaboration et les félicite vivement de l’activité qu’ils ont déployée pendant la campagne scientifique de 1933.

The values given below are those published in each annual report of the international latitude work. They were calculated from the observations at five stations, except the last part of 1934 which was made without Kitab, because the observation books from Kitab since November 1934 have arrived too late at the Central Bureau.

In accordance with action taken by the Commission at the 1932 meeting of the Union, the President has taken steps to ascertain the general opinion of computers and observers in regard to the co-operation of the Nautical Almanac offices in furnishing data for the equinox of 1900. The question under discussion is that of the adoption of the standard equinox to which observations and elements should be referred, e.g. 1900, 1950, etc. The opinion is being ascertained through a questionnaire, the results of which will be reported at the meeting. In this connection Commission 4 proposes discussion of the following resolution in co-operation with Commission 20:

“That, as from 1938 January 1, the equinox used for expressing the elements of cometary orbits and for cometary ephemerides shall be that of 1950.0. Further that, as from the same date, the equinox used in giving observed positions of comets shall be that of 1950.0, unless the observer, for good reasons, used some other equinox and expressly draws attention to the equinox used.”

The past few years have witnessed a great increase in the amount of work done on meteors and in the number of observers. At several observatories programmes of work have been undertaken in the hope of solving specific problems. Several countries now have flourishing meteor societies, or sections of larger astronomical societies, devoted to this field. To solve the problems that have arisen the help of other scientists, especially in physics, geology, and meteorology, has been enlisted to the mutual benefit of all. Historical research, particularly in Asia, has added much to our knowledge of meteor showers for the past thousand or more years.

Depuis la réunion de Cambridge, en 1932, la Commission de la Carte du Ciel a vu, avec un profond regret, disparaître son vénérable et eminent Président d’Honneur, M. Benjamin Bafflaud, artisan de la première heure de l’œuvre de la Carte du Ciel. Il était l’un des rares survivants du Congrès initial de Paris en 1887. Comme directeur de l’Observatoire de Toulouse d’abord, de l’Observatoire de Paris ensuite, il avait pris aux travaux une grande part personnelle; comme Président du Comité international permanent, il avait été, pendant de longues années, l’ordonnateur et l’animateur de l’œuvre. Il n’avait jamais cessé de s’en occuper.