[LM111028], Letter from Arthur Edwin Kennelly to Electrical World, August 3rd, 1888

Item

Abstract

The following are the results of trials made at Mr Edison's Laboratory of three forms of primary battery, and may interest some of your readers.####Yours truly####a.E. Kennelly.####[page 8]####Description of the cells as supplied to the laboratory.####1st. The Roberts-Brevoort battery.####This was a zinc-carbon two-fluid cell. The outer jar --- of wood, rectangular, and metal, lined on the inside, the interest dimensions being 22.5 X 20 X 38 deep cms- (18" X 7-- " X 15" deep). It contained three carbon plates each 40 X 17.3 X 9.6 cms (15 3/4 " X 6 -- X -"), weighing about 900 grammes (2 lbs) and exposing about 1700 sq. cms (264 sq. in.) of active area in solution exclusive of the two extreme faces.####Between these three carbon plates were two of zinc, each in separate jar of porous stoneware. These zinc plates weigh about 1816 grammes (4 lbs) are about 35.6 X 15.3 X 0.4 cms (12" X 6" X-/-) and of their total surface 2150 sq. cms (333 sq. in.) expose jointly about 1850 sq. cms (287 sq. in) actively in solution.####The porous jars were rectangular with rounded corners the interior dimensions being 16.7 X 4 X 35.5 deep cms (6 1/2 " X 1-/-" X 14 " deep) and their thickness was about 0.4 cms (1/6")####The solution in the porous jars round the zinc was of common salt, about 2000 -.- (2 quarts) That in the outer cell being of a special nature about 6000 -.- in amount (1 1/2 gallons) and having the appearance of a preparation from b----nate of potash. The intervening distance between the plates constituting opposite poles was about 2.5 cms (1"), and the total quantity of liquid in the cell amounts to about 10,000 c.s. (2 1/2 gallons)####[page 9]####2nd The Mason-Wood was also a zinc-carbon -- fluid cell. The outer jar was of stoneware expanding upwards, the means internal dimensions being 25 X 12 X 31 deep cm (4-/- " X 7 X 12 1/4 " deep).####It contained two carbon plates metallically connected at their upper edges and 2.5 cms (1") ----- their dimension being 32 X 15 X 0.5 cms (116 sq. in) of surface on the outside faces in solution. They rested in a rectangular jar of porous stoneware occupying the center of the cell. The interior dimensions of the porous jar ---- 16.5 X 5.5 X 17.5 deep cms (6 1/3 " X 2 -/-" X 10 -/- " deep) and the thickness about 0.6 cm (3/16").####The zinc plates were two supported one one each side of the porous cell. Their dimensions were 33 X 15.4 X 0.5 (13" X 6" X -/- ") the weight being about 2300 grammes (5 lbs) and they exposed jointly about 1200 sq. cms (135 sq. in.) of active surface in solution.####Solution in the p---re sells rounds the ------ plates was of a special nature having the appearance of preparation from bicromate of p--sh, and about 1250 c.c (3d galon) in volume. That in the outer jar round the zinc plates was water containing 5% sulphuric acids, ams --ing to about 9000 c.c. (2 1/2 gallons). The total volume of liquid in the cell was then about 12,250 c.c. (2 gallons) and the distance separating the zinc from the carbon plates was about 3.5 cms (1 1/2").####[page 10]####3)####3rd The Fitch "Perfect" Battery.####This is a zinc carbon single fluid cell. It was submitted for trial in two format####(a) In the first form the outer jar was of glass and rectangular, closed by - circular stoneware stopper through which passed a single zinc rod and a single carbon plate. The interior dimensions were 9.5 X 9.5 X 14 deep (3 -/- " X 3 -/-" X 5 1/-" deep)####the zinc rod was 17 cm (6 3/4") long and 1 cm (-/- ") diam: weighing about 63 grammes (2 1/4 oz) The carbon plate triangular in form 17 X 5 mean X 0.7 cms (6 3/4 " X 2 " mean X 5/16") weighed about 90 grammes (3 1/2 oz). The distance between the zinc and carbon was about 2.5 cm (1") The --- is filled to a height of about 10 cms (4") with water a volume of about 1000 c.c. (1 quart) containing -- solution 150 grammes (5 1/4 oz) of a special excitant in the form of white powder.####(b) In the second form not supplied, but --t up according to directions. The outer cell was of glass and rectangular the internal dimensions bein 23 X 15 X 20 deep cms (9" X -" X 7-/-" deep) held 7 plate 4 of carbon and 3 of zinc in alternate order separated by wooden strips and {rightly?] clamped. The carbons were supplied for the purposes. They were ---- 23 X 15 X 1.2 cms (9" X 6" X 1/2") and weighed 73--- (1 lb 12 oz) The zincs were each (-- X 16 X 0.6 cm) (7 1/2" X 6 1/4" X 1/4 ") and weighed about 1470 grammes 93 1/4 lbs) they were amalgamated. the separating distance between the plates -- 0.8 cms (8/16"). The solution was about 8800 0.6 (1 gallon) rose, a height of 17 cms (6%) in the cell and -- ------ -- - -- -- ----- -- (3 -- 6 oz) of the excitant.####[page 11]####4)####------ of testing.####The method employed was the same for all the cells. ------ A set of resistances of -- 0.5 legal ohm was made of stranded platinoid wire, and the cell were set to work continuously through this resistance. The potential difference at the cell terminal was observed every few hours with a potentionate, both while the wire was -- circuit, and while disconnected for a few seconds in order to observe electromotive force. From these observations, the E.M.F., current, Internal Resistance, of each cell were calculated. These observations were plotted on curves shown at figure 1 to 4. From the curves the activity of each cell was calculated.####Roberts Brevoort. Test####These cels were set to work separately and simultaneously on the morning of June 15th on 0.5 platinoid strand. They were not interfered with in way way beyond keeping the water up to level in the porous cells by addition, according to instruction.####The EMF commenced at 2.1 volts####- internal Res. - - 0.06 -####- Current - - 3.8 amperes.####- Activity Extremely - - 7.2 Watts.#####The test lasted for 165 hours.####-- the end of this period the####EMF was 0.45 volt####Internal --- 0.8-#####Current 0.8 ampere####External Activity 0.32 Watt####[page 12: chart]####

Recipient

Date

1888-08-03

Decade

1880-1889

Type

Identifier

LM111028

Folder Set

LM111

Title

[LM111028], Letter from Arthur Edwin Kennelly to Electrical World, August 3rd, 1888

Microfilm ID

109:114

Publisher

Thomas A. Edison Papers, School of Arts and Sciences, Rutgers University