786 RECORD OP CURRENT RESEARCHES, ETC. 



fully considered ; and the singular property of castor oil, discovered 

 by the writer, is referred to. 



As the author's paper on " A Searcher for Aplanatic Images," 

 was inserted in the ' Transactions,' he now introduces a new form 

 which offers some advantages, by its extended traverse, by its sim- 

 plicity and economy of light with increase of magnifying power. 



Finally, some examples are given of producing transcendent 

 definition in cases found hopeless by a niimerous body of observers. 

 The means also of its attainment are minutely described. 



