88 



APPENDIX. 



confeqnence of which, the log line, from the firftufeof that 

 inrtrument about the year 1570, was invariably marked 

 forty- two feet to thirt)^ feconds. Norwood, when he 

 publifhed his Seaman's Praftice, ftated the true meafure to 

 be fiftv-one feet to thirty feconds ; but, as the (hip would 

 really run more tlian is given by the log, and it is right to 

 have the reckoning ahead of the fliip, he recommended 

 marking the log line fifty feet to thirty feconds. It does 

 not appear at what time an alteration either in the marking 

 the log, or the length of the glafs, took place in confequence 

 of thefe obfervations : Sir Jonas Moore in his Navigation 

 which was publifhed in the reign of Charles II. mentions, 

 that the feamen, having found the old log not to anfwer, 

 had fliortened the glafs to twenty-five feconds, which was 

 equal to a line marked fifty feet with a glafs of thirty 

 feconds ; but he rather recommends reftoring the half 

 minute glafs, and making the corredtion on the line. 

 Since that time the feamen, whether from finding the 

 allowance of one foot in fifty not a fufficient compenfa- 

 tion for the accidental errors to which the log is fubject, 

 or from a preference of a meafure nearly equal to the 

 ilatute mile, have ufed a line of forty-five feet to thirty 

 feconds, or a glafs of twenty-eight feconds to forty- two 

 feet. 



All the writers I have met with, who have treated of 

 the log, except Wilfon, have complained of the feamen 

 not having; adhered to Norwood's meafure. Norwood 



himfelf. 



