CURRENT METERS 19 



Audible indicator i, such a* the telephone and the 

 signalling device, have the advantage of enabling the operator 

 to detect an\ MM ^ul.mh. caused by trouble *ith the meter, 

 battery, ele< my part of the equipment. A slop- 



watch is necessjiiN l-.i tic |...|..- r observation of time. 



fling device* are *..m.-imie used, particularly 

 \\hen in. -.i-iii in- tli.- di-rharge of large navigable streams. 

 tin- purpose specially designed boats manned by several 

 assistants are used. 



I MI ^i -i-i \DQfC Mi \ i. K. The Mi-pending d-\ic.-. - 



o||-|-t- ,,| .1 |, M 1 .,| ..I -,,Mie |orm i.|' e.dde. rilll-t pn>\ id*' f.,f 



lowering the m.-i.-i ..n.l \\. i-ht into the \\.ttn and also for com* 

 pl'-tr nt \shich includes the contact chaml<T. 



llic in. -I. i. .in.l the recording device. 



nxl in common use in n>mi< < ii,m v\ith the el 

 recorder consists of a ' inch tube (55) gr.nlu.tt.-il to feet and 

 tent! OHM -in. -lire in carrying, it is made in 1.5 or 



2 foot sections fittcl \>ith *crc\\ tlin-ad>. the 2 foot section being 

 -i.m.l.ml. 'I'hc -IT! the rod are connected l\ flu-h joini* 



\\hich oll'cr no obstruction to the mmcmcnt of the sliding 

 hanger. 



Two metlunU oi li.m^ini: the mcii-r on the rod are in use. 

 By tin- firM the head and tail of the meter are attached to a 

 -in ling hanger (54). \\lrn h can be moved up and down the rod 

 or cluinpeil in .m\ |>o>ition. On the hottom of the rod there 

 is a flat '. \\hich keeps it from >inkin.t: into the bed of 



the stream, and at the top there i- a plug (56) for conne< 

 one ..l ih, NMres from the recording de\ The circuit 



l.et\\een ih, MI. tei cups and the recording device is made by 

 attaching one of the \\ires from the recording device to the plug 

 in the top of the rod. The other wire follows down the rod 

 ami i- attache.! to the contact plug of the meier. In the second 

 method the rod (58) is connected i>\ the screw socket ( 

 in the yoke. 



The rods (51) for use \%ith either type of meter are of J4 

 inch in!. m- graduated to feet and tenth- and. lor cMMxenience 

 in carrying, are made in 1.5 or 2 foot sections which s< 

 together. The bottom rod connects with the contact chain ler 

 (49) by a screw, and is cut so that the zero reading is the plane 



