118 REPORT—1883. 
Report of the Committee, consisting of Mr. Rosert H. Scortr 
(Secretary), Mr. J. Norman Lockyer, Professor G. G. STOKES, 
Professor BALFouR STEWaRT, and Mr. G. J. Symons, appointed 
for the purpose of co-operating with the Meteorological Society 
of the Mauritius in their proposed publication of Daily Synoptic 
Charts of the Indian Ocean from the year 1861. 
THE Committee, appointed at the York meeting in 1881, and reappointed 
at Southampton in 1882, have to report that, in his latest letter from the 
Mauritius, dated June 21, 1883, Dr. Meldrum informs them that, ‘ owing 
to an increase of routine work, the synoptic charts have not made much 
progress since March. However, one month’s charts are in the hands of 
Messrs. A. and K. Johnston, and others will be so soon. The isobars 
have entailed much labour, and they have not yet been finished. 
‘If we cannot present any of the charts to the British Association at 
its next meeting, we cannot help it. For my own part I have worked 
hard, but I am short of assistance.’ 
Under these circumstances the Committee have not thought them- 
selves justified in applying for any portion of the grant of 501. placed at 
their disposal by the General Committee, inasmuch as none of the charts 
have as yet appeared. 
They would, however, request reappointment, with a second renewal 
of the grant, inasmuch as the work is actually in an advanced stage of 
preparation. 
Report of the Committee, consisting of Professor CAYLEY, Professor 
G. G. STOKES, Sir WiLLIam THomson, Mr. JAMES GLAISHER, and 
Mr. J. W. L. GuatisHer, on Mathematical Tables. 
In the Report for 1881 it was stated that the Factor Table for the sixth 
Million had been completed and stereotyped. The Introduction to this 
Million, which relates to enumerations and comparisons extending over 
the whole nine millions, was completed during the present year, and the 
volume has been published by Messrs. Taylor and Francis. The gap of 
three millions between the third million and the seventh million, is there- 
fore now filled in, and the tables extend from unity to 9,000,000. The 
dates of publication of the nine millions are—second, 1814; third, 1816; 
first, 1817; seventh, 1862; eighth, 1863; ninth, 1865; fourth, 1879; 
fifth, 1880 ; sixth, 1883. 
The results of the enumeration of the primes in the sixth million 
were given in the Report for 1881. 
The Introduction to the Sixth Million, which occupies 103 pages, con- 
tains a detailed account of the enumeration of the primes in the first nine 
millions, with a comparison of the results with the values given by 
Legendre’s, Tchebycheff’s, and Riemann’s formule. 
The number of primes is given in each successive group of 1000 
numbers from unity up to 9,000,000, and there are also similar tables for 
groups of 10,000; 100,000; 250,000, and 500,000. The enumeration 
according to centuries is also given in a series of ninety tables, showing 
the numbers of centuries which contain no prime, one prime, two primes, 
three primes, &c., in each group of 10,000 numbers ; and there are similar 
