Vol.. 6, 1920 
INTERNATIONAL ASTRONOMICAL UNION 
365 
(a) Collimators 
(b) Mires 
(c) Nadirs 
(d) Impersonal right-ascension micrometers 
(e) Personal equation apparatus 
(/) Reversing prism on ocular — on microscopes 
(g) Screens or other devices for magnitude 
(h) Flexure — how determined 
(i) Clock — how safeguarded from temperature and barometric changes 
(J) Thermometer installation— use of whirling thermometers — Assman thermometers 
— or other devices 
(k) Printing chronograph 
(/) Devices for stabilizing mercury reflecting surfaces 
(m) Methods of determining corrections for irregularities in the forms of the pivots 
4. Remarks on any novel devices in use, with comments on the value of the same. 
5. Reflected observations of stars. Are they made — how used? 
6. Application of photography to meridian work. 
7. Method of determining graduation errors. 
VI. PUBI^ICATIONS 
1. The present practice varies from publication of the minute detail 
of observations to that of giving only the final results. It is suggested that 
this matter be considered and that a recommendation be made in order 
on the one hand to save the great waste of material and effort involved in 
unnecessarily extended publication and on the other hand to secure the 
publication of as much detail as the consensus of opinion shall decide is 
actually desirable. 
2. Uniformity should be observed in star names, in number of decimals 
for right-ascension and declination, and in use of declinations instead of 
north polar distances. 
3. Standard equinoxes should be adopted. 
4. No proper motions should be applied in observational catalogues to 
reduce from the epoch of observation to the date of equinox of the cata- 
logue. . 
VII. SOUTHEJRN OBSKRVATORIKS 
Attention is called to the need of more southern observatories for meridian 
work in view of the relative weakness of the positions of the southern stars. 
Benjamin Boss, Chairman, Frank Schi^esinge^r, Frank B. Litteji^i. 
REPORT OF THE COMMITTEE ON COOPERATIVE WORK 
WITH THE SPECTROHELIOGRAPH 
In several reports presented to the International Union for Cooperation 
in Solar Research, the advantages of photographing the sun frequently 
with the spectroheliograph at several stations widely separated in longi- 
tude have been pointed out. Without enumerating these, it is evident 
that a more nearly continuous record of the rapidly changing phenomena 
of the sun's atmosphere than we now possess would provide material for 
