158 Capt. R. Wauchope's Signal Jbr ascertaining 



Plate III. 

 Fig. 1. Transverse section of the pale part of Taxodium disticha. 

 a. Annual layer. 



2. Longitudinal section parallel to a radius. 



3. Longitudinal section concentric. 



4. Transverse section of dark part of Taxodium disticha. 



a. Annual layer. 



5. Longitudinal section parallel to a mdius. 



6. Longitudinal section concentric. 



Plate IV. 

 Pig. I. Transverse section of Araucatia, from Moreton Bay, New 

 Holland. 



2. Longitudinal section parallel to a radius, shewing the double 



rows of discs. 



3. Longitudinal section shewing the single rows of discs. 



4. Longitudinal section concentric. 



^o^a.— Fig. 1, PI. I, is not intended to represent the most general 

 appearance of the transverse section of Pinus strobus, but that of the 

 particular part of the wood where the longitudinal sections were made. 



Estahlish7nent of Captain M. Wauchope^s Signal for ascer- 

 taining the Rates of Chronometers at the Royal Observatory, 



Greenwich, 



Dalry House, 

 My Dear Sir, Edinburgh, Gth December 1833. 



Feeling much indebted to you for the publicity which 

 has been given through your Journal, January number 1830, 

 to the plan for ascertaining the rates of Chronometers by in- 

 stantaneous signal, I have much pleasure in mentioning to you 

 that the signal is now established at the Royal Observatory at 

 Greenwich. 



Having been deeply impressed with the importance of esta- 

 blishing a signal for ascertaining the rates of chronometers at 

 Greenwich Observatory, from its central situation, I went, when 

 in London last June, to visit the East and West India Expor- 

 tation Docks and Canal, and found that there were at that time 

 upwards of fifty sail of shipping in the East India Docks fitting 

 for sea, and that there were also many hundred sail of shipping 



3 



