164 



Prof. A. 1). Bachc described the mode in which the self- 

 registering rain gauge, by Osier, employed at the Magnetic 

 Observatory at the Girard College, was adapted to registering 

 the fall of snow. 



He stated that in this climate, during winters of ordinary seventy, 

 if a record of the fall of snow were not kept on the same plan with 

 that of the quantity of rain, a very considerable hiatus would be 

 caused in a year's observations. In Osier's self- registering rain 

 gauge, the water is conducted by a pipe from the funnel of the gauge 

 to the reservoir in which it is weighed. To adapt this apparatus to 

 register the rate of fall of snow, it is only necessary to keep the tem- 

 perature of the funnel and connecting tube a little above that of the 

 freezing point of water. 



Prof. Bache further stated, that an arrangement for this purpose 

 had been made under his direction, by Mr. S. W. Hall, Assistant at 

 the Magnetic Observatory, which had proved completely successful. 

 The funnel of the gauge was surrounded by a metallic casing, con- 

 nected by a pipe, covered with a bad conductor of heat, to a small 

 boiler, placed upon the stove which warmed the Observatory. The 

 boiler being once supplied with water, the steam rising from it kept 

 the funnel moderately warm ; and being entirely condensed in the 

 pipe and casing, the water returned to the boiler. If no leak occur- 

 red in the apparatus, no additional supply of water was necessary. 



Mr. Walker communicated to the Society the principal 

 points of Mr. Simeon Borden's Reply to the Criticism of Mr. 

 F. R. Hassler, on the Massachusetts Survey, as reported upon 

 in the Proceedings of the Society, Vol. II. No. 18, p. 59. 



The criticisms of Mr. Hassler are alluded to in the Pro- 

 ceedings, No. 19, page 98, and may be briefly stated as fol- 

 lows: — 



1. The phrase Chronometric Survey is inapplicable. 



2. The Massachusetts Survey should have been stated to be begun in 1824 



instead of 1831. 



3. The Survey is incomplete till the soundings have been taken. 



4. A sextant of 4 inches radius is unfit for use in a trigonometric survey. 



5. The phrase vertical triangles, in No. 18, p. 60, at bottom, is improper. 



6. Mr. Hassler objects to the mode of deducing the value of a degree of the 



meridian from differences of latitude, obtained by the use of a 4 inch 

 sextant, in the table, page Gl. 



7. The rejection of the four results, stated on page 62, is considered by Mr. 



Hassler as discreditable to the work, being what is called " cooking." 



