Lengths of indicator cards

Oct., 1884.]

Lengths of Indicator Cards.

297

so long as to lap on the barrel and break the pencil point ; and it is generally desirable to get as long a card as the speed will allow.

Table of Lengths of Indicator Cards. STI%O]~ E

OF lo

Y

~

PISTO~.

Inches. 4 5 6 7 8 9 ]0 11 12 13 14 15 ]6 18 20

:::::::i:i:i iiii::::::i: ............

25

i::il.!i!ii!i.,i i

...

2

. . . . . . . . .; . .j . . . . . . . :::::::ii::: .............

............ ............

'2"25

3

3'5

4'5

2'5

2'75 3

3'5

3'75 4 4"5

•

5

24 30 36 4O 42 48

Of course the higher the speed the shorter the card must b% both to prevent " f l i n g i n g " at the ends and to allow a convenient "pull-out" for hooking on. VOLCANIC INTERI~UPTIONS O F TELEPI-IONES.--I)uring the eruption at I~rakatoa 7 telephonic communication was almost impossible at Singapore, the words being drowned by a singular noise which sounded, on a subterranean cable of 1~ kilometers, like pistol shots. The distance between Singapore and the Strait of Sunda, is about 800 kilometers, (497"11 miles). The phenomena seemed to be of an electric nature, rather than aeoustic.--JLu-

mitre _Electrique,

May

3, 1884.

C.