120 



stated respecting the magnetic chariots and hodometers 

 of the Emperor Tching-wang, if you can entirely rely 

 on your authority, gives a far higher idea of the ancient 

 civilization of China than any other fact which has yet 

 been produced. 



In a word, I must congratulate you on the appear- 

 ance of this work as on another great achievement ; 

 and if, as fame reports, it is only the forerunner of 

 another, on the early discovery of America it is 

 only another proof that your funds are inexhaustible ! 

 May you have many years of health and strength 

 granted you to pour them forth, and may each suc- 

 ceeding contribution to our knowledge afford yourself 

 as much delight in its production as it is sure to do 

 your readers in its perusal. 



Miss Gibson writes word that you have more than 

 once inquired of her when my Cape observations will 

 appear. No one can regret more than myself the 

 delay which has taken place ; but it has been unavoid- 

 able, as I have had every part of the reduction to 

 execute myself, and the construction of the various 

 catalogues, charts, and minute details of every kind 

 consume a world of time quite disproportionate to 

 their apparent extent. However I have great hopes of 

 being able to get a considerable portion in the course 

 of the next year into the printer's hands. Some of 

 the Nebulae are already in process of engraving. Per- 

 haps the subject which has given me most trouble is 

 that of the photometric estimation of the magnitudes of 

 Southern stars, and their comparison with the Northern 

 ones. A curious fact respecting one of them, 7 Argus, 

 has been communicated to me from a correspondent 

 in India, Mr. Mackay ; viz., that it has again made 



