8d Mr. Herschel's account of a series of observations 



less than eight out of the twelve nights' observations were 

 totally lost, as to any result they might have afforded, and 

 the remainder materially crippled ; so that a much more 

 moderate estimate of the value of our final result must be 

 formed, than would otherwise have been justified. Still it is 

 satisfactory to be able to add, (such is the excellence of the 

 method) that a result on which considerable reliance can be 

 placed, may be derived from the assemblage of the observa- 

 tions of these four nights ; and when it is stated that this" 

 result appears not very likely to be a tenth of a second in 

 error, and extremely unlikely to prove erroneous to twice 

 that amount, it will perhaps be allowed that, under such cir- 

 cumstances, more could hardly be expected. 



