the Viscosity of Arr. HOD 
§7. Practical Example. The following observations were 
made with two flow tubes. 
Volume of can and tubes (found by mass of water) =S=9646 c.c. 
Barometric height =hj=76°36 cm. 
Barometric pressure = P)=gphy=1-016 x 106 dyne cm.™. 
Density of mercury =p=13-56 grm. cm.~°. 
Length of flow tube 1 =/=64-82 cm. 
Mass of mercury filling flow tube I = M=3-671 grm. 
Hence a2= M|mpl=0-001329 cm.2, a= 1-767 x 10-6 em.?. 
By $6, P=5 >q?. (2 =) = 2-00068. 
Tf 3 n=Kt/)r, 
Je (hey Oe een 
then k= BSI ii Zq°.\ 2 q = ACT a) 5 
Thus, for tube I, 
fe RUDIS SOS SOs ry ent =p 
eamencre 1000s | 
The results obtained with tube I are shown in the following 
table. The table also includes results found with tube II. The 
data for tube II were 
1=77-56 cm., a)*=1:386x10-° cm.4, F= 4 =q?. (s 7) = 100467, 
Hence, for tube II, Kk=7'356 x 10-7 dyne cm. ~°. 
Tube| Time | Gauge readings| P,;— P)|P2—-Py| == 
secs. | cm. cm. cm. cm. 
I 0 | 36:26 | 13-80 | 22-46 OLOW AIO PANS. | 
120 | 30-20 | 19-93 10-27 
i O | 33°81 | 16-28 | 17:53 Oe Ba || este so WO 
120 | 29:08 | 21-08 8:00 
i Qj SISO | Ue ISS) 0:749 | 1:80 x 10™ 
120 | 27-80 | 22-40 5-40 
th) 0 | 36:39 | 13:66 )22-73 0-742 | 1:78 x 10- 
180 | 30°10 | 20-06 10-04 
en On 0315) 20-00) L015 Oe DI) Wee x WO 
180 | 27-40 | 22-77 4°63 
Tl | 0 | 32:49) 17-65 | 14-84 | O-SD || UG) se WO 
180 | 28-30) 21-88 | 6-427 
