Open main menu

Page:Popular Science Monthly Volume 90.djvu/966

This page needs to be proofread.


��Popular Science Monthly

��the 8-hour or normal rate. With the 3- series, 8-paralIel battery the most con- venient way is to charge it with bichromate batteries. These cells are cheaply and easily made of zinc and carbon scrap. They have a potential of about 2 volts and are high in amperage. Connect the two groups of 5 in series and place the two groups in parallel. Also connect the 8 units of storage-battery in parallel and connect with


��^ OFF

��F)&7 When the storage-battery is used on an audion it is necessary to supply an end switch

the bichromate batteries. Be sure to con- nect the zinc element of the bichromate cells with the negative of the storage- battery. This is shown in Fig. 5. This method of connecting the storage cells in parallel series is only for the purpose of charging. When used on the discharge they must be disconnected at the binding posts and connected in series as in Fig. 6.

The cells during the charge should give off gas. Toward the end of the charge they should gas freely. A failure to gas is a sure sign something is wong. An insuffi- cient voltage or a short circuit in some one cell may be the trouble. When the negative begins to gas freely, or when the electrolyte turns to a milky color, it is a good sign that the cells are charged. A slight overcharge will do no harm. An overcharge is fre- quently used to clean out the elements.

The battery fully charged will give a voltage of about 60 when connected in series. To provide the most efficient volt- age for an audion it is necessary to supply an end cell switch, as shown in Fig. 7. The voltage will soon drop to about 50 where it remains practically for the life of the charge. Do not discharge to a lower voltage than 42. A light charge should be given every two weeks.

��A New Wireless Station on the African Coast

ANEW wireless station has been erected on Cape Juby, on the African coast. In cases of need at sea the service is avail- able for ships in distress. As the installa- tion on Teneriffe Island is less than 100 miles from the Cape Juby plant, communi- cation with the Canary Islands is possible and, through them, with the Spanish mainland.

Cape Juby is a sandy and practically barren projection into the Atlantic Ocean some 67 miles from the Island of Fuerteven- tura of the Canary group, and in the same latitude. It is a part of that section of the western Sahara which extends along the Atlantic coast and connects the Mogador district with that of the Rio de Oro. The last named was recognized as Spanish territory by the treaty of Paris of 1900. Water is very scarce on the cape, although it can be obtained in the ravines by sinking wells. The interior region is said to support great numbers of sheep and to produce excellent crops of wheat, barley and corn. The ocean fisheries at this point are very abundant.

��A Light Signal to Designate a Blown Fuse

WHERE there are a number of fuses on one block and the block is placed in a dark corner, a blown fuse is hard to locate without a light or pocket flashlamp. To eliminate the wiring for a lamp and have a light ready to locatethe burned-out fuse the arrangement shown was' installed. Each of the fuse-cartridges in the block was shunted through a low candlepower lamp. Such a lamp will not affect the rating of a


��A low candlepower lamp glows when the fuse is blown and until another is installed

fuse to any extent and will not glow until the fuse is blown. — Jessie C. Haskell.

�� �