FLUIDITY AND PLASTICITY

If

Number
Diameter
Temperature
Surface

A . ....
0.0014
10
Glass 1

B ...............
0.0270
10
Glass \ Poiseuille

C ................
0.0650
10
Glass J

D
0.615
5
Lead No. 4 \ -Q i
C\R

E
1.270
5
f i ^T f c Jtteynoi Lead No. 5 J

F ..............
1.400

Lead

G ................
2.700

Lead

H
4.100

Lead

I .....
2.600
12
Varnished

J ................
8.260
21
Varnished

K ...............
19.600

Varnished

L .
28.500
21
Varnished

M ........
8.190
15
Cast iron, new

N ...............
13.700
15
Cast iron, new

O ................
18.800

Cast iron, new

P ..............
50.000

Cast iron, new

O
24 320

Cast iron, incrusted

R
24.470

Cast iron, cleaned

S ................
4.968

Glass

the oscillations in the mixed regime is entirely characteristic, it
seems hardly probable that we can always sharply differentiate the
mixed from the hydraulic regime. Indeed Couette (p. 486)

FIG. 15.—Coaxial cylinder viscometer of Couette.

found that with a tapering tube the oscillations do not appear at
all. One may draw the conclusion from Reynolds' observations