32 SCIENTIFIC CATALOGUE. 



Penrose (F. C.) ON A METHOD OF PREDICTING BY 



GRAPHICAL CONSTRUCTION, OCCULTATIONS OF 

 STARS BY THE MOON, AND SOLAR ECLIPSES FOR 

 ANY GIVEN PLACE. Together with more rigorous methods 

 for the Accurate Calculation of Longitude. By F. C. PENROSE, 

 F.R.A.S. With Charts, Tables, etc. 4to. izs. 



The author believes that if , by a graphic method, the prediction ef 

 occupations can be rendered more inviting, as well as more expedi 

 tious, than by the method of calculation, it may prove 'acceptable to 

 the nautical profession as well as to scientific travellers or amateurs. 

 The author has endeavoured to make the whole process as intelli 

 gible as possible, so that the beginner, instead of merely having t* 

 follow directions imperfectly understood, may readily comprehend 

 the meaning of each step, and be able to illustrate tJie practice by the 

 theory. Besides all necessary charts and tables, the work contains 

 a large number of skeleton forms for working out cases in 

 practice. 



ROSCOC. Works by HENRY E. ROSCOE, F.R.S., Professor of 

 Chemistry in Owens College, Manphester : 



LESSONS IN ELEMENTARY CHEMISTRY, INORGANIC 

 AND ORGANIC. With numerous Illustrations and Chromo- 

 litho of the Solar Spectrum, and of the Alkalies and Alkaline 

 Earths. New Edition. Thirty-first Thousand. i8mo; cloth. 

 4*. 6d. 



It has been the endeavour of the author to arrange the most important 

 facts and principles of Modern Chemistry in a plain but concise 

 and scientific form, suited to the present requirements of elementary 

 instruction. For the purpose of facilitating the attainment of 

 exactitude in the knowledge of the subject, a series of exercises and 

 questions upon the lessons have been added. The metric system sf 

 weights and measures, and the centigrade thermometric scale, are 

 used throughout this work. The new edition, besides new wood 

 cuts, contains many additions and improvements, and includes the 

 most important of the latest discoveries. f ' We unhesitatingly pro 

 nounce it the best of all our elementary treatises on Chemistry" 

 Medical Times. 



SPECTRUM ANALYSIS. Six Lectures, with Appendices, En- 

 gravings, Maps, and Chromolithographs. Royal 8vo. 2U. 



