1896.] Mr. A. Siemens on Gable Laying on the Amazon Biver. 217 



WEEKLY EVENING MEETING, 

 Friday, May 15, 1896. 



Sir Frederick Bramwell, Bart. D.C.L. LL.D. F.E.S. Honorary 

 Secretary and Vice-President, in the Chair. 



Alexander Siemens, Esq. M. Inst. C.E. M.B.I. 

 Cable Laying on the Amazon Biver. 



When it had been decided to connect Belem, the capital of the State 

 of Para, by means of a subfluvial cable with Manaos, the capital of 

 the State of Amazonas, a preliminary journey became necessary, 

 during which landing places at the various intermediate stations had 

 to be selected, some reaches of the river explored, as no reliable 

 charts exist, and various other details ascertained in order to facilitate 

 the laying of the cable. This preliminary survey took place in 

 October of last year during the hottest season, when the river was at 

 its lowest ; while the cable was laid during January and February of 

 this year, when the rainy season had commenced and the river was 

 rising. 



The difference in temperature between the two journeys was on 

 the average not more than about 6J° Cent. (10° Fahr.), but a great 

 advantage during the laying was the almost continuous presence of 

 clouds, which mitigated the fierce heat of the sun and kept the tem- 

 perature at a very pleasant level. 



A diagram on the next page shows the curves of the variation in 

 temperature during the cable-laying expedition, giving the daily 

 maximum and minimum temperature registered by a thermometer 

 hung up under the officer's bridge in the open air, but sheltered from 

 the sun. The third curve represents the temperature of the water, 

 which was measured by a thermometer on the refrigerating machine, 

 fixed at a point where the water pumped in from outside first enters 

 the machine. Besides the date, the places where the observations 

 were taken are marked on the diagram, and it will at once be noticed 

 how very equable the temperature was on the main river. The 

 fluctuations in the air temperature mostly indicate the absence or 

 presence of clouds, but the water temperature remained perfectly 

 constant during the whole time spent on the upper reaches of the 

 river, the proximity of the sea lowering the temperature only to a 

 small extent. 



A glance at the map of South America explains, without much 



