Note on Continuous Beams. 503 



the manner above described possess the following useful 

 properties : — 



Constancy of resistance, 



Small temperature-coefficient, 



Negligible capacity, 



Negligible self-induction, 



Ease of adjustment to definite value; 

 and to these may be added the power of standing a high 

 voltage without variation ; a megohm having been subjected 

 to 105 volts for five days without experiencing any detectable 

 alteration in its value. 



My best thanks are due to Prof. Chattoek for his many 

 valuable suggestions and kind help during this research. 



LI I. Note on Continuous Beams. (^ 



To the Editors of the Philosophical Magazine. 

 Gentlemen, 



I NOTICE in the September issue of the above magazine a iQ 

 " Note on Continuous Beams," by Mr. H. J. Tomlinson 

 and Professor Karl Pearson, in which reference is made to 

 my paper " On a Method of Determining the Reactions at 

 the Points of Support of Continuous Beams " (Proc. Royal 

 Society, vol. lxii.). 



Whatever may be the relative merits of graphical and 

 arithmetical methods of solution, it is always desirable to have 

 both, and I wish therefore to call attention to a few points in 

 the solution I offered which may tend to remove the objections 

 preferred by the authors of the note. 



In the first place, as stated in my paper, almost all the 

 arithmetical work to which objection has been raised can be 

 replaced by the simple graphical construction there given, the 

 plani meter being used to measure the areas from which the 

 coefficients for the final equations are obtained. The arith- 

 metical method was preferred owing to the fact that in order 



" M" 

 to construct the original — j- curve a certain number of 



ordinates must in general be calculated, and these may be 

 used in avoiding the planimeter. 



The arithmetic involved is simple, and although the tables 

 appear formidable yet they can be quickly constructed by 

 means of the slide- rule, and the tabular form itself has a 

 certain value in office work. 



After having shown how the reactions cculd be obtained 

 I hardly thought it necessary to indicate that the bending- 

 moment and shearing-force curves could be erected from these 

 data if thought desirable. 



