212 THE POPULAR SCIENCE MONTHLY. 



method, with a small telescope, upon the brightest of all the stars, he 

 was supplied by the Royal Society of London with a larger instru- 

 ment to pursue the investigation. The results of his spectroscopic 

 inquiry into the motions of many stars have been published. Where 

 these results have conflicted with the foregone conclusions of astron- 

 omy, Huggins has not hesitated to arraign the accuracy of astronomi- 

 cal data and methods. I have freely admitted the delicacy and diffi- 

 culty of the geometrical process. The spectroscopic analysis, when 

 applied to the same problem, walks upon slippery ground and must 

 take heed lest it also fall. The alleged displacement is a nice quan- 

 tity, and instrumental sources of error have been pointed out which 

 may explain away the whole of it. I lay no stress upon the large dif- 

 ference between Vogel and Huggins in the quantity of motion which 

 spectrum analysis ascribes to Sirius, inasmuch as the direction of the 

 motion is the same. We do not yet know all the elements which the 

 earth contains. The spectroscope has already added four to the num- 

 ber. There is reason to think that the stars, though having some sub- 

 stances in common with the earth and sun, are not without their pecu- 

 liarities. The lines in the stellar spectra may be out of position, not 

 because they are the displaced lines of sodium, magnesium, and hy- 

 drogen, but in consequence of novelties in the gaseous atmospheres 

 of the stars. Still, there will be a presumption, perhaps a probability, 

 in favor of Huggins's deduction, if it rests on a sound basis of theory. 

 If there is any weakness in the physical and mathematical foundation 

 of his argument, gratifying as it is to the imagination and the aspira- 

 tions of science, the whole superstructure must fall. 



-+*+- 



THE EARLY STUDY OF GEOGRAPHY. 1 



By Major WILSON. 



BEFORE concluding this portion of my address, I would draw 

 your attention to the appliances used in the minor schools of 

 this country for teaching geography, as they would seem to need some 

 improvement. The appliances to which I allude are models or relief 

 maps, wall maps, atlases, and globes. The use of models as a means 

 of conveying geographical instruction has been too much neglected in 

 our schools. If any one considers the difficulty a pupil has in under- 

 standing the drawing of a steam-engine, and the ease with which he 

 grasps the meaning of the working model, and how from studying the 

 model and comparing it with the drawing he gradually learns to com- 

 prehend the latter, he will see that a model of ground may be used in 



1 From the Opening Address of the President of the Geographical Section of the Brit- 

 ish Association. 



