ON THE RAINFALL IN THE BRITISH ISLES. 383 



Report of the Rainfall Committee for the year 1868-69, consisting of 

 C. Brooke, F.R.S. {Chairman), J. Glaisher, F.R.S., Prof. Phillips, 

 F.R.S., J. F. Bateman, C.E., F.R.S. , R. W. Mylne, C.E., F.R.S., 

 T. Hawksley, C.E., Prof. Adams, F.R.S., C. Tomlinson, F.R.S., 

 Prof. Sylvester, F.R.S., and G. J. Symons, Secretary. 



The attention of the Rainfall Committee has during the past year been 

 largely devoted to various arrangements and details calculated to secure in- 

 creased uniformity and accuracy amongst their observers ; a very consider- 

 able number of stations have been visited during the past year by our Secre- 

 tary, and the observers have been further instructed on any points in which 

 their practice -was incorrect ; besides which the following code of rules has 

 been drawn up for their guidance. 



I. Site. — A rain-gauge should not be set on a slope or terrace, but on a 

 level piece of ground, at a distance from shrubs, trees, waUs, and buildiugs 

 — at the very least, as many feet from their base as they are in height. Tall- 

 growing flowers, vegetables, and bushes must be kept away from the gauge. 

 If a thoroughly clear site cannot be obtained, shelter is most endurable fi-om 

 N. W., N., and E., less so from S., S.E., and W., and not at all from S.W. or jST.E, 



II. Old Gauges. — Old established gauges should not be moved nor their 

 registration discontinued until at least two years after a new one has been 

 in operation, otherwise the continuity of the register will be irreparably de- 

 stroyed. Both the old and the new ones must be registered at the same time. 



III. Level. — The funnel of a rain-gauge must be set quite level, and so 

 firmly fixed that it will remain so in spite of any gale of wind or ordinary 

 circumstance. 



IV. Height. — The funnel of gauges newly placed should be 1 foot above 

 grass. 



V. Rust. — If the funnel of a japanned gauge becomes so oxidized as to 

 retain the rain in its pores, or threatens to become rusty, it should have a 

 coat of gas-tar or japan black. 



VI. Flo.\.t Gauges. — If the measuring-rod is detached from the float, it 

 should never be left in the gauge. If it is attached to the float, it should 

 be pegged or tied down, and only allowed to rise to its proper position at the 

 time of reading. To allow for the weight of the float and rod, these gauges 

 are generally so constructed as to show only when a small amount of 

 water is left in them. Care must always be taken to set the rod to the zero 

 or 0. 



VII. Can- and Bottle-Gauges. — The measuring-glass should always be 

 held upright ; the reading is to be taken midway between the two apparent 

 surfaces of the water. 



VIII. Time of Reading. — Nine a.m. daily ; if only taken monthly, then 

 9 A.M. on 1st. 



IX. Date of Entr?. — The amount measured at 9 a.m. on any day is to 

 be set against the previous one, because the amount registered at 9 a.m. of, 

 say, 17th contains the fall during 15 hours of the 16th, and only 9 hours of 

 the 17th. {This rule, aiyproved of hy the Meteorological Societies of Enqland 

 and Scotland, cannot be altered, and is particularly commended to the notice of 

 observers.) 



X. Mode of Entry. — If less than one-tenth (-10) has fallen, the cipher 

 must always be prefixed ; thus, if the measure is full up to the seventh line, 

 it must be entered as -07, that is, no inches, no tenths and seven hundredths. 



