BIGELOW: EXPLORATIONS IN THE GULF OF MAINE. 93 



or warmer : and in August of that year, he shows all of the Gulf, in- 

 cluding the Bay of Fundy, 59° to 68°, Massachusetts Bay above 68°. 



But without access to the vessels' logs, and other unpublished data 

 from which these charts were compiled, it is useless to discuss them 

 critically further than to point out that the distribution of tempera- 

 tures within the Gulf represented on them does not accord with condi- 

 tions in 1912, with VerrilPs observations, or with the occasional surface 

 readings which I have made in other years. The surface temperatures 

 taken by the Grampus in July, 1908, while crossing the mouth of 

 Massachusetts Bay on her way to the Gulf Stream, (Bigelow, 1909) 

 were 66° to 68°, i. e., appreciably higher than they were in 1912. 

 This fragmentary data suggests that the surface waters in the Bay and 

 over the Gulf as a whole, were colder than usual during the summer of 

 1912; the result of abnormally low air temperatures during the pre- 

 ceding winter, the coldest in eastern Massachusetts for many years. 



Unfortunately the only previous records of bottom temperatures 

 within the Gulf, those recorded by Verrill, (1873-1875) are not reliable, 

 as shown by the fact that when two thermometers were used simulta- 

 neously their readings occasionally differed by as much as 4.5°, fre- 

 quently by 1° or 2°; indeed it was the exception that they registered 

 alike, and as Verrill himself pointed out, they rated differently at 

 successive standardizations. His records, taken at their face value, 

 would indicate that the bottom temperatures were distinctly lower 

 in the northeastern part of the Gulf in 1873 than they were in 1912; 

 i. e., the reading, with both thermometers, in 107 fathoms, in Septem- 

 ber, 1873, twenty-three miles southeast of Matinicus Rock, was 39.5°; 

 in 105 fathoms just east of Jeffrey's Bank it was 40°, whereas it was 

 42.8° at Station 27, in 1912. Fifteen to twenty miles southeast of 

 Cape Elizabeth, the discrepancy is still greater, for Verrill records 

 bottom temperatures of from 36° to 39.5°. But these differ so much 

 from those of the Grampus (41° to about 45°) and are so much lower 

 than he himself records from any other part of the Gulf, that it seems 

 that the instrumental readings were too low. In the deep basin off 

 Grand Manan, Verrill found the bottom temperature 37.5° in 106 

 fathoms in 1872, but we have no data to compare with his; and this 

 basin is isolated from the exterior by a sill over which there is only 

 about eighty fathoms of water. 



Fifteen miles southeast of Boon Island, in the trench west of Jeffrey's 

 Ledge, the older record is about 39° (37.5° and 40.5°) in ninety-five 

 fathoms, instead of 40.3° which we found to be the general tempera- 

 ture at that level (Stations 11, 41), though at one Station near by (12b) 



