46 Mr James Straton on the Rain-Gauge. 



In the summer months, we have gentle showers, with little 

 wind, and the records are almost identical ; but in the winter 

 months, when heavy rains, snow, and strong winds prevail, 

 then the difference is quite enormous, being fully a fourth 

 part of the quantity registered. Like the flat plate and the 

 saucer — equally useful in calm, equally useless in storm — 

 with this all-important difference, however, that the elabo- 

 rate and expensive gauge is not simply useless, but posi- 

 tively pernicious, because it is trusted in as truthful, yet is 

 really false. It is much to be regretted that the enlightened 

 and liberal intentions of the Commissioners to serve science 

 and humanity are so completely frustrated in this respect. 



Materials. — Gauges are sometimes made of zinc, tin, and 

 iron, but copper is most generally preferred. Most of those 

 which are considered the best in use, have the receiver and 

 part of the cistern of copper, the other part of the cistern of 

 glass, and a brass plate attached, on which the scale is en- 

 graved. This form of the instrument is simple enough in 

 use, but it is the most complicated and costly in construc- 

 tion, and decidedly the most liable to destruction, from al- 

 ternations of temperature, particularly from frost in winter, 

 by the unequal contraction and expansion of the different 

 substances. 



As glass is found suitable for part, it must be much more 

 suitable for the whole of the cistern, being much less liable 

 to injury from change of temperature when alone than com- 

 bined with any of the common metals ; and being suitable 

 for the cistern, it is equally so for the receiver, — for the 

 whole instrument, in a word. 



I consider glass a peculiarly suitable material for the rain- 

 gauge ; because (1.) the workmanship is so simple that the 

 price is trifling, whilst it can be accurately measured and 

 graduated, and consequently it will be as efficient in use as 

 any other material. (2.) It is also the most simple in use. 

 The scale can be engraved on the cistern ; the quantity can 

 be seen at any moment, without measuring, adjustment, or 

 calculation : the readings can be taken and the record kept 

 by any boy or girl who can read and write inches and deci- 

 mals. (3.) There is least error from evaporation. Every 



