from a Body cooled by a Stream of Fluid. G05 



to the table* and formuhef for Z/X previously published, 

 makes (19) a practical formula. 



9. Tables of the Values of the Function Z/X. 



z. 



Z/X. 



I 



Z/X. 



I. 



Z/X. 



3-0 



05399 



44 



05925 



5-8 



06180 



32 



0-5550 



4-6 



05964 



60 



0-6211 



34 



05656 



4-8 



0-6002 



6-2 



0-6240 



3-0 



0-5734 



50 



06040 



6-4 



0-6267 



3-8 



0-5793 



5-2 



0-6077 



6-6 



0-6293 



4-0 



0-5842 



5-4 



0-6113 



6-8 



06317 



42 



0-5885 



5-6 



0-6147 



70 



0-6339 



i 



10. Simplified Formulas for Cylindrical Tube. 



In many practical cases m 2 W, which equals irsaYW\ak, 

 is a large number, and thus we may write 



JL_± 



When we do this (19) hecomes 



/GO 



H«8VSV^ *.{-»■ £ 



3 V3 



= sm' 



Zirl 



1 . 2 5ttZ 

 5 vo *« 



- — * |sin ^ + 3 2 sm -^ + ....j 



If a = 21, so that we have lengths of the tube I, at tempe- 

 ratures 6 and — 6 Q , separated by lengths I at temperature 

 zero, we have 



H = 4 



1 



V2RV^^o(l+^+- 



.J — ^ak0 o , 



and noticing that 2 7^ — t-t\3/2 

 we get 



3 V3 5 s/h ) 2 



= 1*6888 approximately, 



H = 13\51R 



/sakXl 



O - 7rlk0 o . 



. (21) 



} 



(20) 



* Savidge, Phil. Mag. Jan. 1910, p. 56. 



t Russell, Phil. Mag. April 1909, pp. 529 & 532. 



