[LM111016], Letter from Arthur Edwin Kennelly to Thomas Alva Edison, August 2nd, 1888

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Title

[LM111016], Letter from Arthur Edwin Kennelly to Thomas Alva Edison, August 2nd, 1888

Editor's Notes

The following are the results of the trials we have made with Mr Fitch's "perfect" battery.####The first best was made with the cells in the form supplied by Mr Fitch, in which the zines has the rod shop. Five of these cells made up in the manner described by Mr Fitch in his printed and written instructions were set to work steadily on one ohm of wire. The EMF commenced at 1.33 volts####current - - 0.5 ampere####-- Int. - - 2.0 w nearly.####In one hour the EMF had fallen to 0.44 volts 0.25 ampere####Int. --- 2.0-- nearly.####After this the EMF slowly fell until it was 0.2 volts####after 72 hours the current being then 0.1 ampere.####The seond best was inside with two cells made up in the manners recommended by Mr Fitch and as follows:####Each meter glass cell 23x13 --- holds the solution 1 gallon of water containing 8 packets of Mr Fitchs [excitant?]. The plates were -- , form of Mr Fitch's carbons 23 X 15 X 1.3 cms and three zinc amalgamated 19 X 16 X 0.6 cms clamped together with separating blocks of wood 0.8 ems shick. The active exposed surface of zinc was about 1350 sq. cms.####The two cells set up in precisely the same way were set to work simultaneously on separate wires of 0.5 platinoid.####The ----- accompanying, shows the behavior of cells. The current was less than one ampere soon after commencing work and fell [slowly?] to 0.8 amperes after 96 hours. The highest EMF was 0.7 volts after the first half hour.####The [cell?] is clean, en--- to set up, and like the Belanche may be good for discontinuous work, but for the supply of a strong and continued current such is requiredfor the phonograph motor it appears ---- the above results to be totally unfitted, and one practical enlargement of the plate surface would fit it for such work####I remain Dear Sir####Yours very truly####A.E. Kennelly.####3rd August 8####Editor####The Electrical World####Dear Sir####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.####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 was of wood, rectangular, and metal lined on the inside, the [interest?] dimensions being 22.5 X 20 X 38 deep cms. - (15" X 7 7/8" X 15" deep). It contained three carbon plates each 40 X 17.3 X0.5 cms (15 3/4" X 6 3/4 X 5"), weighing about 900 grammer (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 1815 grammes (4 lbs) are about 35.6 X 15.3 X 0.4 cms (14" X 6" X --") and of their total surfaces 2150 sq. cms (333 sq. in.) expose jointly about 1850 sq. cms (287 sq. in) actively in solution.####The porous jars were rectangular with sounded corners the interior dimensions being 16.7 X 4 X 35.5 deep cms. ( 6 1/2" X 1 5/8" 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 c.c. in amount (1 1/2 gallons) and having the appearance of a preparation from [bieronate?] 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.c.( 2 1/2 gallons)####The Mason Wood was also a zinc carbon -- fluid cell. The outer jar was of stoneware expanding upwards, the mean internal dimension being 25 X 18 X 31 deep cms (4 7/8 " X 7 X 12 3/4" deep).####It contained two arbon plates metallically connected at their upper edges and 2.5 cms (1 ") [apert?] their dimension being 32 X 15 X 0.5 cms (12 1/2 " X 5 3/4 X 1/3 ") and exposing jointly about 750 sq. cms (116 sq. in) of surfae on the ouside faces in solution. They rested in a rectangular jar of porous stoneware occupying the center of the cell. The porous interior dimensions of the porous jar [average?] 16.5 X 5.5 X 17.5 deep cms (6 1/2 " X 2 1/8 " X 10 7/8 " deep) and the thickness about 0.6 cm (3/16 ").####The zinc plates were two, supported one each side of the porous cell. Their dimensions were 33 X 15.4 X 0.5 (13" X 6" X 1/5 ") The weight being about 2300 grammes (5 lbs) and they exposed jointly about 1200 sq. cm (185 sq. in) of active surface in solution.####Solution in - porous cell sounds the ------- plates was of a special nature having the appearance of preparation from bicromate of p----h, and about 1250 c.c. (3rd gallon) in [asalume?] That in the outer jar round the zinc plates was --ater containing 5% sulphuric acid, [amounting?] to about 9000 c.c. (2 1/2 gallon). The total volume of liquid in the cell was total volume of lilquid in the cell was theirs about 1-,250 c.c. (2.5 gallons) in the distance separating the zinc from the carbon plates about 3.5 cms (1 1/2).####3rd The Fitch "Perfect" Battery. (3####This is a zine carbon singular fluid cell. It was submitted for trial in two format#### (a) In the first form the outer --- was of glass and rectangular, closed by a circular stoneware stopper through which passed a single zinc rod and a single carbon plate. The interior dimensions were 4.5 X 9.5 X 14 deep (3 3/4" X 3 3/4 " X 5 1/2 " deep)####The zinc rod was 17 cms (6 3/4 ") long and 1 cm (3/8") 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 cms (1") The --- is filled to a height of about 10 cms (4"0 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 a white powder.####(b) In the second form not supplied, but at up according to directions, the outer cell was of glass and rectangular the internal dimensions being 23 X 15 X 20 deep cms (9" X 6" X 7 7/8" deep) held 7 plates 4 of carbon and 3 of zinc in alternate order separated by wooden strips and rightly lamped. The carbons were supplied for the purpose. They were each 23 X 15 X 1.3 cms (9" X 6" X 1/2") and weighed 730 [qr?] (14r 12oz) The zincs were each (19 X 16 X 0.6cm) (76" X 64" X 8") and weighed about 1470 grammes (3 1/4 lbs) They were amalgamated. The [deparating?] distance between the plates was 0.8 cm (0/16"). The solution was about 3800 c.c. (1 gallon) rose, a height of 17 cms (6 3/4") in the cell and [estimated?] ---- 12 07 ------ -- --- (3-- 6 oz) of the excitant####[Note in the margins: a active surface a zinc in solution was about 13560 sq. cm 210 -----####Method of Testimony####The method employed was the same for all the cells. If a – of resistances of 0.5 legal ohm was made of stranded plati--- wire, and the cells were set to work continuously through this resistance. The potential [defenses?] at the exit terminal was observed every few hours with a [potentionate?], both where the wire was in circuit, and write discriminated, for a few seconds in order to observe electromotive force. From these observations, the E.M.F. current, Internal Resistance: of each cell was calculated. These observations were plotted on curves shown at figures 1 to 4. From the curves the activity of each cell was calculated.####Roberts Brevoort, Test####Three cells were set to work separately and simultaneously on the morning of June 15th on [A.S.W?] platinoid st—nd. They were not [interfered?] with in any way beyond keeping the [ratio?] up to level in the porous ells by addition, according to instructions####The EMF commenced at 2.1 volts####- Internal Res. - - 0.6 - #### - Current - - 3.8 amperes#### - Actively Externally - - 7.2 Watts.####--- test lasted for 165 hours.####On the end of this period the####EMF was 0.45 volt####Internal --- 0.08 - ####Current 0.8 ampere####External activity 0.32 Watt####[Page 12 is a chart]####

Mentioned

Date

1888-08-02

Type

Folder/Volume ID

LM111-F

Microfilm ID

109:112

Document ID

LM111016

Publisher

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