﻿Barus and Strouhal — Viscosity of Steel. 



465 



Table 26. — Apparatus IV. 



i?=314 cm ; £=27 cm ; Z<02 cm . Rods: No. 33, glj 

 34, annealed at ]000°, ^= + 180°. 2p=0-082 cm . 



-hard, ^=-180°; No. 



Date. 



(j>x 10 3 



h 



o xlO 3 



Date. 



0xlO 3 



h 



<£ xl0 3 



21/7, 4M5 m 



4 43 



5 23 



1-249 

 1-089 

 1-022 

 0-957 



o-oo 



0-47 

 1-13 

 1-50 

 1-95 



(*) 



— 0-149 



+ 0-010 



0077 



0-142 



29/7, 



9 h 02 m 

 12 45 

 4 31 



— 2-324 



— 2-367 



— 2-409 



189-18 



3-467 



5 45 



6 12 



30/7, 



9 h 00 m 

 1 13 

 4 22 



-2-583 

 — 2-633 



-2673 



212-61 



3-730 



22/7, 8 h 42 m 



162 



0-042 



— 0250 



-0-185 



16-45 

 19-75 

 2530 

 26 95 



0-937 

 1-057 

 1-249 

 1-284 

 1-547 

 1-658 

 1-727 





12 00 

 5 33 

 7 12 



31/7, 



9 h 52 m 

 12 41 

 4 01 



-2850 

 -2882 

 — 2-912 



236-61 



3-982 



23/7, 7 h 53 m 

 12 36 

 3 36 



-0-448 

 — 559 

 -0-628 



39-63 

 4435 

 47-35 



2/8, 



10 h 02 m 

 1 24 

 4 10 



-3-264 

 -3-291 

 -3-312 



284-95 



4-389 



24/7, 9 h 23 m 

 12 59 

 4 19 



-0-024 

 — 0-985 

 -1-038 



68-64 



2-082 



3/8, 



9 h 47 m 

 1 22 

 4 24 



-3-423 



-3-436 

 -3-442 



308.93 



4-534 



26/7, 9 h 05 m 

 12 14 

 3 52 



-1-540 

 — 1-581 

 -1-6*3 



116-14 



2-685 



4/8, 



l h 38 m 

 4 26 



-3-548 

 — 3-560 



33478 



4-654 



5/8, 



l ll 40 m 

 5 27 



— 3-660 

 —3-675 



359-31 



4*768 



27/7, 9 h 03 IU 

 12 34 

 4 10 



— 1-807 

 -1-851 

 -1-895 



140-35 



2-951 





6/8, 



9 h 14 m 

 5 28 



— 3-733 



— 3 777 



381-10 



4-855 



28/7, 9 h 29 m 

 1 16 

 4 23 



-2-081 



— 2-125 



— 2-159 



164-79 



3-222 





7/8, 



9 h 22 m 

 6 43 



-3-829 

 -3863 



405-80 



4-946 



* Adjusted r + b+f. 



Remarks on the Tables. — In experimenting with couples of 

 two glass-hard wires, or with couples in which one of the wires 

 is annealed at 100°, the degree of hardness of the harder wire 

 is an exceedingly important factor. Hence these curves 

 (tables 5, 5 A, 6, 6 A, 7, 8) appear under a variety of forms. 

 Only tables 5A, 6A, 7, 8 are used in the digest constructed 

 below. The results in tables 19, 24, 26 change their curva- 

 ture after August 1st. Since the same error is found in all the 

 wires then examined it is probably a result of temperature. 

 When minutely examined (cf. table 23, for instance), the 

 curves show a sinuous outline which is quite marked and prob- 

 ably also due to temperature, or to tremors. If the curves for 

 stated temperatures and times of annealing fail to coincide it is 

 due to differences in the tempers of the glass-hard wires, to 

 similar differences in the tempers of the annealed wires, to pre- 

 existing strains accidentally imparted to one wire or the other, 

 to lack of perfect uniformity of temper throughout the efficient 

 lengths, to unavoidable inequalities of the sectional areas of the 

 pairs of wires. The last-named error probably also effects the 

 curvature. Yiscous rotation of the arms which carry the mir- 



