98 



PROCEEDINGS OF THE AMERICAN ACADEMY. 



It is the object of this paper to present the quantitative laws that, 

 from the engineering standpoint, control continuous-current artificial 

 lines (sections of resistance and leakance) in the steady state. The 

 basis for the construction of these formulas is given in the Appendix. 

 All of the formulas apply equally to simple alternating-current artificial 

 lines (sections of resistance, inductance, capacity, and leakance) when 



A B C D E 



♦--'vwwvvwvw- • 'VWvM/yvvvvv v •■ , v^AA^fAAA^v^-^-AA/^AAAA/vvvw-^ 



v 



A 



E' 



Figure 1. — Single-conductor type of artificial line. 



interpreted vectorially, or expanded from one dimension to two, in 

 the well-known way; but in order to keep within reasonable limits 

 of space the explicit discussion of alternating-current lines cannot here 

 be considered. 



Types of Artificial Line. 



There are two types of artificial line; namely, the ground-return- 

 circuit line of Figure 1, and the metallic-return-circuit line of Figure 2, 



ABODE 



A B' C r D' E' 



Figure 2. — Double-conductor type of artificial line. 



which are sometimes respectively defined as the single-conductor and 



double-conductor artificial lines. The former is characteristic of wire 



telegraphy, and the latter of wire telephony. In order that two such 



types of line should be equivalent, ignoring questions of lumpiness, 



circuit balancing, and circuit symmetry, it is necessary and sufficient 



AB + i'B' 

 that each section AB of Figure 1 should have a resistance — 



