60 REPORT—1885. 
and quaterdiurnal compound tides, would also require special treatment, 
which may easily be devised. 
At ports, where the diurnal tide is nearly as large or larger than the 
semidiurnal, special methods will be necessary. 
Although the treatment in terms of mean longitudes makes the cor- 
rections larger than in the other method, yet it appears that the compu- 
tation of a tide-table may thus be made easier, with less reference to 
ephemerides, and with amply sufficient accuracy. 
Report of the Committee, consisting of Mr. Rospert H. Scorr 
(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. 
Drawn wp by Mr. R. H. Scorr. 
Tue Committee have the honour to forward, for the inspection of the 
members of the Association, a copy of the Charts for the month of March 
1861, with some specimens for January of the same year, and the com- 
plete number for February which appeared some yearsago. These docu- 
ments have recently arrived from the Mauritius. 
As the work has now made decided progress, the Committee have 
applied for and obtained the grant of 50/. placed at their disposal by the 
General Committee. 
As soon as the requisite documents are received from Dr. Meldrum, 
the Committee will submit a formal account of their expenditure with 
tle necessary vouchers. 
Report of the Committee, consisting of Mr. JAMES N. SHOOLBRED 
(Secretary) and Sir WituiaM TuHomson, appointed for the re- 
duction and tabulation of Tidal Observations in the English 
Channel, made with the Dover Tide-gauge; and for connecting 
them with Observations made on the French coast. 
Your Committee herewith beg to submit the High Water and the Low 
Water Observations for the years 1880, 1881, 1882, and 1883, obtained 
from the records of the self-registering tide-gauges at the ports of Dover 
and of Ostend respectively. 
The observations, in erder to facilitate comparisons, are reduced to 
Greenwich time and to the common datum-plane of 20 feet below the 
Ordnance datum of Great Britain. 
As the reduction and tabulation of the present series of tidal observa- 
tions has proved a longer operation than was anticipated, there has been 
hardly sufficient time to consider the best form in which those observa- 
tions should be placed for comparison, nor for the more suitable deductions 
which may be drawn from such comparison. 
Your Committee, therefore, request to be reappointed. 
re 
