390 O. Becker — Gravity Determinations at Sea. 



believes that the redaction of the observations made at these 

 two places is on the whole without value. He ought, how- 

 ever, to have noticed the comparison of the corrections k a for 

 the four series of observations, proving that a combination of 

 the observations made on shore with those made on board was 

 impossible, because the photographic barometers were greatly 

 altered, having been dismounted for the transport from ship 

 to land, and vice versa. I have, moreover, expressly drawn 

 attention to this fact. Hence the observations made in Rio de 

 Janeiro and in Lisbon could not be reduced together. Regard- 

 ing the two visual barometers, the mean value of the readings 

 was taken : (in consequence of their greater want of precision), — 

 this also cannot be taken into consideration, for, on my second 

 cruise, I could not make any observations with them. In this 

 place, he also says, that the terms with b, e, d, of his formula 

 »5) as well as l\ were omitted in the adjustment of the observa- 

 tions made on laud, and that they were only taken into account 

 for the adjustment of those made at sea. I repeat, that this is 

 not so ; on these two cruises c and d do not enter into the equa- 

 tions of the observations made at sea. 



As to the differences resulting for the observations made on 

 board ship, when the ship was anchored in the harbor, engines 

 at rest, and when the ship was in motion, her body being put 

 into regular vibrations through the working of the engine, I 

 regard it as proved that these differences are a consequence of 

 the above-mentioned different conditions under which the 

 whole apparatus works, and which are typical for each ship, 

 depending upon her construction. (Coinp. p. 159 of "Best. d. 

 Schwerkraft anf dem Schwarzen Meere."') 



Further on Bauer states that the observations made on the 

 vessels at rest agree badly. This, of course, cannot be other- 

 wise, for, as is well-known, highly damped barometers, when 

 perfectly at rest, do not have very accurate readings. 



I considered it quite a matter of course, that all the influ- 

 ences coming into consideration on one cruise were to be 

 derived independently from the observations made on the par- 

 ticular cruise ; as already stated, I had continually to change 

 ship, and, therefore, the instruments had to be dismounted and 

 packed for transport. Sometimes the} 7 remained packed for a 

 long time before being put together agaiu for use. Consider- 

 ing these circumstances, it cannot be supposed that the correc- 

 tions of the barometers would remain constant. 



Further on Bauer asserts (in italics): "The corrections for 

 Hecker's thermometers were never redetermined after they 

 had once been furnished by the German Physikalische Reichs- 

 anstalt." This places the matter in a wrong light. 



The corrections for the calibration of the boiling thermome- 



