CHARLES BABBAGE. If'l 



those who have credited it; whereas the forger is one who, wishing to 

 acquire a reputation for science, records observations which he has never 

 made. This is sometimes accomx3lished in astronomical observations 

 by calculating the time and circumstances of the phenomenon from 

 tables. The observations of the second comet of 1784, which was only 

 seen by the Chevalier d'Angos, were long suspected to be a forgery, and 

 were at length proved to be so by the calculations and reasoning of 

 Eucke. The pretended observations did not accord among each other 

 in giving any possible orbit. But M. Encke detected an orbit, belong- 

 ing to some of the observations, from which he found that all the rest 

 might be almost precisely deduced, provided a mistake of a unit in the 

 index of the logarithm of the radius vector were supposed to have been 

 made in all the rest of the calculations. {Zach. Gorr. Astro7i., torn, 

 iv, p. 456.) 



Fortunately, instances of the occurrence of forging are rare. 



Trimming consists in clipping off little bits here and there from those' 

 observations which differ most in excess from the mean, and in sticking 

 them on to those which are too small ', a species of " equitable adjust- 

 ment," as a radical would term it, which cannot be admitted in science. 



This fraud is not, perhaps, so injurious (except to the character of the 

 trimmer) as cooking, which the next paragraph will teach. The reason 

 of this is, that the average given by the observations of the trimmer is 

 the same, whether they are trimmed or untrimmed. His object is to 

 gain a reputation for extreme accuracy in making observations; but 

 from respect for truth, or from a prudent foresight, he does not distort 

 the position of the fact he gets from nature, and it is usually difficult to 

 detect him. He has more sense or less adventure than the cook. 



Of Coolcing. — This is an art of various forms, the object of which is 

 to give to ordinary observations the appearance and character of those 

 of the highest degree of accuracy. 



One of its numerous processes is to make multitudes of observations, 

 and out of these to select those only which agree or very nearly agree. 

 If a hundred observations are made, the cook must be very unlucky if 

 he cannot pick out fifteen or twenty which will do for serving up. 



Another approved receipt, when the observations to be used will not 

 come within the limit of accuracy which it has been resolved they shall 

 possess, is to calculate them by two different formulas. The difference 

 in the constants employed in those formulas has sometimes a most 

 happy effect in promoting unanimity among discordant measures. If 

 still greater accuracy is required, three or more formulas can be used. 



It must be admitted that this receipt is in some instances most 

 hazardous ; but in the cases where the positions of stars, as given in 

 different catalogues, occur, or different tables of specific gravities, spe- 

 cific heats, &c., it may safely be employed. As no catalogue con- 

 tains all stars, the computer must have recourse to several ; and if he is 

 obliged to use his judgment in the selection, it would be cruel to deny 



