298 SCIENTIFIC RECORD FOR 1884 



We see from this that in general the average of G4 per cent, will rep 

 resentall these observations with equal accuracy, and that there is nosen- 

 sible diminution in the quantity of rain from G7 up to 2G0ieet above the 

 earth's surface. It is also well known that there is only a slight per- 

 centage of increase in the velocity of the wind as we go from 07 up to 260 

 feet, and the conclusion drawn from other observations is, therefore, 

 corroborated by this present table, according to which the rapid dimi- 

 nution of rain caught by gauges whose altitudes are between zero and GO 

 feet is due almost wholly to the increase of the wind at the high alti- 

 tudes. The large deviations from average results shown by different 

 gauges, even at the same altitude, depend upon the shape of the rain- 

 gauge and its location, and especially upon the configuration of those 

 parts of the building that are near it. (Z. 0. G. M., xvii, p. 294.) 



[The results given by Bornstein (§143) show that this injurious effect 

 of altitude is almost wholly neutralized by Mpher's improvement.] 



146. Capt.C. Eung, of Copenhagen, describes a form of self-registering 

 rain-gauge which he calls the sine balance, wherein the weight of the 

 water is balanced by a heavy lever arm; the water acts on a constant 

 leverage, and the weight on a variable one the sine of whose angular 

 variations is proportional to the weight, and is recorded upon an end- 

 less, sheet of i)aper. The same principle applies to the record of evapo- 

 ration, the growth of plants, &c. The cost of this ombrograph, as 

 manufactured by Kemp & Lauritzen in Copenhagen, is about $75. (/>. 

 M.Z.,1, p. 4G1.) 



147. Dr. Maurer describes a form of self- registering rain-gauge which 

 preserves a continuous record of the rainfall and the time; it is manu- 

 factured by Hottinger, of Zurich, and has already been extensively in- 

 troduced by Austrian, Eoumaniau, and other meteorological services. 

 {Z. 0. G. M., XIX, p. 180.) 



148. Dr. Assmanu, of Magdeburg, has established a station upon the 

 Brocken, where he has erected a self-recording rain-gauge, which ap- 

 parently runs without trouble throughout the whole winter; the snow 

 caught therein is melted by the heat from the chimney, and immedi- 

 ately flows to the measuring apparatus in the room below, thereby avoid- 

 ing the great loss that occurs when strong winds blow. The rain-gauge 

 is surrounded by a large shield of wire net work, as suggested by Nipher. 

 The exjieriments have shown that snow at a temperature of — G° centi- 

 grade, on being thrown into the gauge,was within G seconds collected 

 within the room below, as warm water at a temperature of 10^. An 

 apparatus for the measurement of the quantity of frost formation that 

 accumulates on every exposed surface is described as follows : Two iron 

 rods, 1 meter high, have at their lower ends a wide-open flask, into 

 which flows the water which may result from any melting due to the 

 sun's heat. One of these rods and flasks is exposed at the moment 

 when the other is taken in ; when brought in all the frost upon the rod 



