294 Description of the 



nearly one hundred, in the form of concentric coils, yet neither 

 could produce a heat a!)ove redness on the smallest wires. At 

 my suggestion, Mr. Peaie separated tlie two surfaces in his coils 

 into four alternating, constituting two galvanic pairs in one re- 

 cipient. Iron wire was then easily burned and platina fused by 

 it. These facts, together with the incapacity of the calorific fluid 

 extricated by the calorimotor to permeate charcoal, next to me- 

 tals tlie best electrical conductor, must sanction the position I 

 assigned to it as being in the opposite extreme from the columns 

 of De Luc and Zaniboni. For as, in these, the phaenomena are 

 such as are characteristic of pure electricity, so in one verv large 

 galvanic pair, they almost exclusivvly demonstrate the agency of 

 pure caloric. 



i 



XLVIII. Description vj the JMarine Thermometer Case in- 

 vented by Mr. Robert Jamieson, of Glasgoia*. 



I Glasgow, Maich 10, 1820. 

 , beg leave, through vou, to present for the inspection of 



the Society, a Marine Thermometer Case which I have con- 

 structed for Captain Livingston. The directions given to me by 

 that gentleman, were, to make a case capable of preserving a 

 thermometer from being broken when lowered into the sea, and 

 drawn up again from the side of a ship ; also, that it should ad- 

 mit water at any given depth, and retain it during the drawing 

 up of the instrument, so as to enable a thermometer of the usual 

 construction to indicate the temperature at different depths, un- 

 disturbed bv tlie greater or inferior heat of the surface water. 



The accompanving statement, drawn up by Captain Livingston 

 and confirmed by his own experience, of the utilitv of tiiermome- 

 trical observations to the navigator, renders wliollv unnecessary 

 any remarks of mine on the saine subject. I shall therefore con- 

 fine myself to the mechanical construction of the instrument as 

 exhibited in the drawing and model herewith transmitted. In 

 order to answer its purpose, it was necessary to combine in the 

 construction, strength, simplicity, and portability; but although 

 these objects have been attained so as to produce a practically 

 advantageous result, I am far from claiming for it absolute per- 

 fection. Longer experience and greater skill will probably be 

 able to improve upon the present first attempt ; and it is with 

 this view, and also in order to call the public attention to a sub- 

 ject which promises to be highly beneficial to this maritime na- 



* From the Transactions of Ihe Socicti/ for the Encouragement ff Arts, 

 i^nwufaclures, and Commerce, for 1820. The large Silver Medal of the So- 

 ciety was voted to Mr. Jamiegoii for this commuoication. 



tion. 



