40 To the River Plate and Back 



States lie north of the equator. But when one arrives 

 below the equator one sees constellations different 

 from those which fill the northern heavens. Many of 

 them have been defined and named in comparatively 

 recent times, and bear designations which are quite 

 unfamiliar to us who have always done our star-gazing 

 " north of the line. ' We are familiar with the Greater 

 Bear and the Lesser Bear, with Cassiopeia and Androm- 

 eda; we know Orion and the Greater and the Lesser 

 Dog; but we have never seen Pavo, the Peacock; 

 A pus, the Bird of Paradise; Horologium, the Clock; 

 and Equus Pictorius, the Painter's Easel. The Air- 

 pump, the Sculptor's Workshop, the Telescope, and the 

 Microscope are constellations new to us. We do not 

 see these and twenty other constellations either in 

 Germany or the United States. 



The progress made in astronomical science during the 

 last century has been as great as that which has been 

 made in any other department of science. Much of 

 this progress is due to the refinements in instrumental 

 equipment which have been made possible by the 

 ingenuity of men who have had at their command the 

 mechanical devices of the nineteenth century. The 

 huge telescopes which are used to-day could not have 

 been constructed in those ages which lacked the steam- 

 engines, the lathes, the screw-cutting machinery, and 

 other appliances which are found in modern workshops. 

 The science of astronomy owes a great debt to such 

 consummately skilled mechanics as Alvan Clark of 

 Cambridge and others. The invention of the spectro- 

 scope and the application of the knowledge acquired 

 through its medium has vastly extended our acquaint- 

 ance with the physical composition of the sun and other 

 celestial bodies. Many of the secrets of the skies 



