THE INVENTION* OF DR. C. FRAUCI <* JEHKIHS OF WA^TNfJTON.D.C. A The«i" prepared by William -Hart ge Fifer a = part of hi" initiation into the Maryland Beta Chap- ter of the Tau Beta Fi Association, the Honorary En^in- rering Fraternity of the University of Maryland. P& \ SUMMARY Dr. Charles Francis Jenkins of Washington, D.G. has pro- duced some of the io"t remarkable discoveries of this raechani- cal age. He i« the father of the motion ricture industry .hav- ing invented the prototype of the motion ricture projector now u^ed in every theater in the world- He invented the apparatus which ^ent and received the first radio photographs an d a "hort while later produced an apparatus for viewing distant scenes by radio directly, and radio movie° for hone entertainment. Devel- oping the spiral wound all rarer container used the world over for the transportation of liquids in "mall quantities i» to also credited to him. He has been granted over four hundred patent and maintain a private laboratory in Washington. He owns 8 ,nd operate radio station W3XK where r^dio movie* 5 are broadcast at a regular schedule. He has made several important invention pertaining to aviation. Here truly is a man that the world can give its thanks to for many of the luxuries ^nd comforts that peorle tod^y enjoy. -1- DR. C. FRAHCI* JEHKIH** Dr. C. Francis Jenkir. i w** born in the country near Day ten, Ohio in 1B68. His* parent* were Quakers. He "pent his "boyhood on a farm near Richmond, Indiana where he attended the county grade and high school . On graduation from high school he attended Earlham College from which he was* graduated in 1PP7. After graduation he explored wheatfield* and timber re- gion" of the Northwest and cattle range" and mining camp«! of the Southwest T, nited states. He came to Wa^hington.D.C* in 1B90 a° "ecretary to dinner I. Kimball of the TT nited ^ate" Life ^ving ^rvice.the forerunner of the present TT nited "States. Coast Guard. He resigned from the notation in 1^95 to take ut> inventing as* a profession. To d--<te he ha" been granted over four hundred patent most of which are on motion ri ctu re <*, rad- io photograph e , and radio movie". He i" a member of the Frank- lin Institute, the American Association for the Advancement of ^cience, the National Aeronautical Association, and is founder of the "ociety of Votion Picture Engineers. TTe ha* v P pn awar- ded the Elliot tQresson "old Medal by the Franklin Institute and also the John <*cott Medal by the City of Philadelphia for his motion ricture machine. He has a commercial airnlane pi- lots license and ovn" and operates hi° own plane* In June 1929 he was awarded the honorary degree of Doctor of Science by Earlham College of Indiana. -2- Dr. Jenkin* Fome at 5502 <*ixteenth <*t. ,N.W. , Washington, D.C» Ur. Jenkins maintain* a private laboratory at 1519 Connecticut Ave. ,N.W. , Washington, D.C. where he employ* *even a*«l*tpnt*. He own* and operate* radio station W3XK at Wheaton Md. wher* r^dio movie* are broadcast on a regular schedule. -3- THE INVENTION" OF DR. C. FRANCI" JENKINS In hi* rrivate l^borntory on the second floor o r 1519 Connecticut Ave. , Washington ,D.C -Dr. Jenkins and hi" *ts.ff of a""i»tant" have produced *ome of the most rermrknble invention of t i ~ ^cienti^ic age* It i* due to the keen in- ventive brain of Dr. Jenkin* that we have many of our -present day luxuries =<nd comfort". PR0T0T v TE MOTION PICTURE PROJECTOR The mo*t notable of hi* early work* de^l with photo- graphy ^nd motion ricture machine*. He invented the r ir"t printer* and devploper* used by the Eastman Kodak Co. of Roch- ester, N.Y. and it i* due to the^e early di*coverie" that the motion ricture inn chine was developed. Dr. Jenkin* made the fir«t long mtrip film motion ricture mchine by fastening to- gether roll* of Kodnk film ^nd cutting them in thin strip". The pre*ent type projector u"ed the world ov<=r and which ha* made the modern motion ricture ^o*«ible i" entirely due to him. HIGH "(PEED CAMERA Thi* camera wa* de*igned for the "tudy of high veloc- ities or high *reed motion*, "uch a* the 'light of a projectile. It has a normal rate of exro*ure*.of from 1000 to 3000 pictures per second, and a* high a* 4000 Pictures per -econd have been successfully obtained. 4- It U"es standard "nrer-"peed motion picture negative film and i« developed in the u"ual manner. The film i° pro- jected in the standard projecting machine which give" a reduc- tion of 100 to 200 in the apnarant speed of the photographed object, which make" it" motion and reaction" irmch easier to "tudv. The camera u»e» 48 Zei"" Te^ar len"e s, "ize F«3*5 and of 2" focu°. The camera i * operated by an ordinary auto- mobile starting motor and a 12 volt storage battery. tannine or illumination equivalent to "un<-»hine i" sufficient ^or it* operation. The "ecret of this camera lie* in It* len*» system as each len" may work g* much a." 150 rer cent of the time, that i *•• to say, the exposure* overlap. TIRAL-WOUHD FAR ALINED ALL PAPER CONTAINER Thi« i * the familiar round wrer container which i° used in many confectionery "tore" a« a container for ice cream or other liquids which require a cheap practical method of transporting liquid". "Prom a monetary "tandroint thi<* wa" one of hi" met «ucce""ful invention". RADIO PHOTOGRAPH ^ Dr. Jenkins rrodueed the fir<*t photographs ever "ent by radio and produced the fir«t aimaratu" for viewing distant "cene" by rauio. TT i" first work on thi" mbject began in 1913 and wa° continuously -pursued *^il he was inter runted by the -5- World War to which he gave all hi" aid. After the termination of the War he developed a prismatic ring, a new contribution to the optical science. Tt i" comparable to a "olid gla«*" rri*m which change" the angle between it" °ide",giving to a beam of light x>a«"ing through an oscillating action on one "ide of the ^ri a m while holding a fixed axis of the beam on the other "ide of the rri«m. The prismatic ring "ection i" ground into the face of a gla"" di«c. From one end to a point half way around it ha« it° ba"e outward and from thi". noint around to the other end hsvin^ it« ba"e inward. r k PftiSMft Tt C /?//V g It wa" with the development of the prismatic ring that the fir"t real «ucce"" w»« obt^inpd in the tran"ni""ion of picture" and virion by rriio,for it i » by the u"e of the"e prismatic ring" and a light «en"itive cell at the "ending sta- tion that the light value* which make up the ^icture htp conv- erted into eletrical current" -mi broadcast 'i 9 i" nccom- pli"hed by "weering the picture aero"" the light sensitive cell hy mean" of the*e rotating prismatic ring". With each -6- downward "weec the picture i*? mov^d one one-hundredth of an inch to the right until the whole picture ha" osc'ed the light «»en o itive cell which convert" the light strength of the differ- ent ps.rt" of each •'lice into corresponding electrical current*. It i « immaterial whether the current modulation i" taken from a flnt photogfaph.a <=olid object or an out-door <*cene at w'::ich the transmitter i " directed. At the distant receiving end it i° onl - " nece'^ary to rut the a e light value" back again by revpr^ing the froce"". Thi* i " accomplished by having a -noint of light to draw line" aero " the photographic rlace, which i* done by the i-ri^matic ring" and by varying the strength of the different of the "ucc- e° p ive line" correTonding to the light" and "hadow* of the -ricture at the transmitter which i« done by the vary init *trf>n- gth of the incoming r^dio "iiTn^l which cau^f* corrp "bonding change" in the intensity of the light. The "puree of light i*> obtained from a filament lamp which con^i^t" of => "inglp turn coil ^nclo^pd in an atr.o-'phere of hydrogen. The variation of light i * caused by imvre«"ing the incoming raaio signal* an thi« Lamp c'fter the filament hae been brought to a dull red by a battery. -7- W.J. Brvan J. •=!. Montgomery PHOEOffRAFH <3 «ENT AND RECEIVED BY APPARA'^r ^ I SVM TE D BY DR . C . FRAHCI 5 JBHK IS <*. June, 15 , 1 9 24 . in the In/order thnt pending machine ^nd receiving machine will i run/exact synchronism a control fork was perfected. The con- trol of the sending and receiving motors i« maintained by the vibration of a rather heavy fork at each station and are ad- justed to beat together, with a slight automatic conection by fcadio as may be required td keep the folk* irt all of the re- dETfing station" in synchronism with that of the transmi Uer. It is a simrle and very dependable method. Another method of keening the motors in "ten is to have a small synchronous radio suitor controlled by rower radia- ted from the broadcasting station. It is rotated partly by thi° rndiated -rower and partly y -~' a local current jn^t as n _n- a loudspeaker is orprated. These small motor" regulate the rotation of a larger motor nnd thus kenr> t v *=m in step with the tren smiting station. Thi° method to the present time i« the ao«t practical and give* the he c t reeults in "ending ^icturp-* by r'Hdio. RADIO VISION AND MOVIES After obtaining ouch wonderful results in rndio photo- graph « Dr. Jenkins '■ mediately began to develop some practi- cal mean e of transmitting picture" of moving object'' and mot- ion picture^. When transmitted and received by th<= flat rlate method radio virion in identical in principle to the method by which radio photograph" are broadcast with the only difference being in the speed of transmission. A" in radio photographs the Picture is formed by a small srot of light moving over the picture in 'uccp'^ive parallel lines, with the light value controlled by the incoming rsdio signals. The whole -picture is covered in one- sixteenth of a second and the r^r^i stenc* 3 of vision of the human pye enables us to see the whole picture- Tn order to get this great in- crpase in speed a lens di«c i e substituted for the pair of nri- smatic rings. -9- L?.H" DIX TAilNPIR Screen The rotation of the di"c carrying the len«e" arranged in a priral cau^e" 9 the light to "weer aero" 9 the screen. A "need of one- «ixtpenth of a second v&r revolution of the di <*c will give a motion picture screen effect. The Radio Virion receiving 9 et a" designed by Dr. Jenkin* 1« very =imrle and all the a v ^arat-ii* may "be -placed in a ^mall box beside the radio "et ^nd one may ^ee a distant football game or inaugural cerera^nv or my <*ee a motion picture transmitted from a film. n-7 wF -10- Simple Standard Four Tube Radio Vision Receiver 46.7 METERS SPEAKER. NEON UMfl ■ ' 'I'M 230 TO 300 V. - C j U to 45V. CI — 2 pieces 1} 2 " square copperplates spaced C2- -.01 M.F.D. Mica coupling condensers C3— At least 1 M.F.D. C4 — At least 4 M.F.D, CS— .00025 M.F.D. C6— .00014 M.F.D. Variable condensers C7— .001 M.F.D. SW — Speaker and Neon Lamp cut-out switch All resistors must be non-inductive R— 2 to 7 megohms Rl — .025 megohms , Rp .25 megohms Rg — 1 megohms Rgl — .5 megohms LI— 5 turns 3" dia. Wo. 18 D.C.C. Wire L2 -6 turns 3" dia. No. 18 D.C.C. Wire LI and LZ — Spaced 'i" Antenna— 50 to 100 feet total length Dr. Jenkiri" made hi* fir«t fcfeboratory demonstration of Radio Virion and Radio Movie" on June 14,1923 before a very distinguished gathering of gue^t^f^ee visitors li<*t). I dkc^M 9Z^k - 0?T. ?;ii/^y^\ oW^ $$m<j*+ ^ jL&rA*. fUi ■<z ■ Km* ^0^>~v *"* <&*-~, -, hi, f H-i .^1 U/WW /%. ^ to / Uh% "1 ^.^*^-* *"-^r- <Jl—-c. t* t [/■/rr <3^ o i_J ClTWK 4 ■^%^<-W i ■ 11- HELICAL i3RUl£ BANNER With the dice "Conner the minimum ~e~nration of the aperature c determine 1 " the width of the picture and &<» the pic- ture i " -square the aperture *eparation al «so determine* the off- set of the end" of the spiral. Tn order to have a Picture 2 ir.che" square a 36 inch diameter di^c i«» required and 6 foot dia- meter di*c for a 4 inch picture* In order to have a picture of reasonable "izp with apparatus of "mall dimension* hp dpvplo^ the Helical Drum Scanner. f?BUR Tf>RGE7 CATHODE GlO* HELICAL DRHM "CA^JPTO In the peripheral wall of the drum 48 hole-> are drilled. There are four helicnl turn 1 ' of 12 hole= each. Each hole being "T-ced 2 inche" apart circumferentially and the helical turn a being £ inch apart. In the middle of the drum there i* 5 placed a 4 target c nth ode- glow neon lamp. Between the lamu and thp rer- phery of the drum are small quartz rod®, each rod ending -13- it* particular minute aperture in the peripheral wall. The p e qusrtz rod" a^ei a« they have the property of conducting li through it with a very small lo«i. The cathode target* are placed one under each of the row* of quartz rod« and are light- ed in «ucce i »^ion through b commutator, '~v the ^late current of the power tube of the receivpr. Each helicil turn of the «ean- ning aperture i° lighted inderendentlv "by its own particular glowing target, which result*, in a great economy of current re- quired for lighting the entire Picture. A "even inch diameter drum of this type will give a Pic- ture 3" X 3" which may be magnified to 6" X 6" and from four to five neo-rle mav watch it. A 10£ inch drum "ill -^ive a Picture four inches square which ma" be magnified to a ricture 10 in- ches Square. The photograph shows how the drum receiver may be u-^ed in the home. Dr. Jenkins operate? radio station W3XF* at Wheaton.Md. which operate s on a wavelength of 46.7 meter". He broadest i rr^dio movie" from this station on a regular schedule. r ^ ^mmtSK*-'- i £-; ^'^ ; L A JE^KIS 6 * RADIO. MOVII TRAtf'VTTTER W3XK, AT WHEATOH/MD, -13- PLATI RECEIVER The di «c- "canning receiver, with 48 aperature^ in the ^riral on the dJ e c,ha« a current-to-eye efficiency of le^** than one fifty thousinth of one percent. Thi* low effiency i« due to the fact that each elementary area light "ource should "be a" large a" the whole ricture and that persistence of virion of the eye i« not defended u^on for an assembly o f the element! ; area" of the ricture. Theoretically there should be no more light current than is needed to light a single elementary area at the time considered and a real nlcture should <=ri«t in the receiver whether there i« a human eye to "pe it or not; that is, it "hould he T-o^'-iW to photograph the received picture with a <»nap shot camera which cannot he done with the lens Ji'^e scanner. The rlate receiver satisfies both of these conditic and ocn^iet" of a ricture ""l«te divided into 2,304 elementary areap. This may be built by having 48 horizontal row™ of flash light bulb* with 48 bulb" in each row. The "e lamps are divided, electri clly into four groups and each lamp is indivi- dually wired to it* 5 rarticul3r contact of the "witching gear. All the lamp" in each group have a common return. The "witohin/* p.paf §fm"i*t* 0? n ooramatotor having four separate sections, one for each group of lamps, a 3,600 RIM J-B-P* synchronomous motor i» used to drive the commutst-ftf In orierati en, the incoming radio signals are distri- buted to the several lsmr* in <mcce <s< *ion and the lamp* are lighted according to the inten^it" "■ c ' the signals. The result -14- i ° a r-icture 2 feet square made up in li^ht* and halftone and "hadow. The ricture i° made up of the glowing lamp*! which Tr e i=t in light value for the a^rreciable time of about one tenth of a °econd. A" the impulse to each lamp is every one- fifteenth of a *econd the lamp i ° glowing for the whole time the corresponding elementary aref> o^ the ^cene at the broadcas- ting station is alight. That i° to iny , rer e i ■>t< a nce of light i<* u e ed in^teau of per Ki^tenoe of vision a? in the len^-di^c and dr'irr. receiver. Another advantage of the --ytem i 9 that the light cr.lor is white and net the pinkish color of a npon light. A* nearly all "uch *y stems are reversible, an excellent transmitter may be made by reversing the «y«tem,u*ing light »en< = itive cpII 15 in place of the lamps. -15- BIBLIOORAFHY Virion by Radio, Radio Photograph* and Radio photogram*. published by Jenkin* Laboratories, Inc. in 19P.5. Radiorccvie*, Radiovi=ion and Television. Published by Jenkine Laboratories, Inc. , in Feb 1929. Varioi:<» rtaort articles and sketches from tine to tine in the Electrical Engineer, Hot ion Picture Hew*, Popular Radio, Radio Hew*, Newspaper article*, etc», "beginning in 1B94. Department of Commerce OFFICE OF THE SECRETARY WASHINGTON February 1,1924, Mr .G .Francis Jenkins , 1519 Connecticut Avenue, Washington ,D .0 . Dear Mr .Jenkins: £ wish to express my appreciation for the photograph which you so kindly sent me. It represents a very startling development in radio and sometime when I hare some leisure I would be interested in discussing the method with you . Yours faithfully Ideal Radio Vision Receiver Using Standard Parts SHIELDS ._ L... 23a ZSO TO 3»¥W, 1^1—2 pieces \}4" square copper plates spaced C2 — .01 M.F.D. Mica coupling condensers C3— At least 1 M.F.D, C4— At least 4 M.F.D. CS— .0002S M.F.D. C6 -.00014 M.F.D. Variable Condensers C7— .00014 M.F.D. Variable Condensers CS— At least .01 M.F.D. CS> — .001 M.F.D. Mica Condenser Antenna -SO to 100 feet total length SW — Speaker and Neon Lamp cut-out switch "All resistors must be non-inductive" R — 2 to 7 megohms Rl -.025 megohms Rp — .25 megohms Rg — 1 megohms Rgl — .S megohms L —6 turns 3" dia. No. 18 D.C.C. LI 5 turns 3" dia. No. 18 D.C.C. L2 — f> turns 3" dia. No. 18 D.C.C. LI — and L2 —Spaced I ., " UX-222 — Requires only 3.3 volts on filament iuly 31, 1928. C. F. JENKINS SPIRAL MOUNTED LENS DISK Filed Jan. 2, 1925 1,679,086 'B Pi A fTcj 2. „_J WttrUJUti ©A. s $usu V*. OLSu~^i^, ^tvuetttot Patented July 31, 1928, 1,679,086 UNITED STATES PATENT OFFICE. CHABX.ES FBANCIS JENKINS. OF WASHINGTON, DISTRICT OF COLUMBIA. SFIBAL-MOU NTED LENS DISK. Application filed January 2. 1925. Serial Ho. 323. tfl IT) HO ■<:; :tn 3Q 40 This invention relates to apparatus for the transmission of pictures by radio, in which the picture is made up of lines across an approximately itat surface, said lines having varying values. The principal object of this invention is the design of a simple device which permits of a speed which will cover the entire pic- ture surface within the time of persistence of vision, say. one-twelfth or one-sixteenth of a second. With these and other objects in view the invention consists of the novel details of construction and combination of parts mom fully hereinafter disclosed and particularly pointed out in the claims. Referring to the accompanying drawing forming a part of this specification, Figure 1 is a front view of the lens-carrier disk, and Figure -2 a schematic drawing showing how it is employed Tn the drawing A is a disk with a plural- ity of spirally arranged holes therein, over each of which a lens is mounted, as B, B\ B", etc. The dUk is intended to be rotated between a spot-source of light L, and a pic- ture surf nee or screen M, shown edge on. When the lens 15 is in front id the light the image of the source strikes the screen near the top, as shown in full line; when the lens li" i ition to project, the image will appear on the picture surface near the bottom, as indicated by the dotted line; when other lenses come into pnsiti m to pro- ject, the images fall in successively differ- ent positio is between these extremes. It will-readily be understood that the ro- tation of tiie disk would cause the lenses lo travel across the screen from side to side; while I lie location of the lenses at different radial distances from the a.\is makes the lateral trips of each lens at different levels, so that the whole picture surface is scanned. It will also lie understood that the disk- mounted lenses could just as well scan a *&•. picture surface to he sent as they scan a screen upon which (he picture is put, with- out departing from (he spirit of my inven- tion. What I claim, is— W 1. "In combination, a stationary picture surface, a stationary Jjghf translating ele- ment, a lotatahle disk interposed between said surface and said element, said disk lift- ing provided with a v plurality of apertures M of huge dimensions as compared with an elementary area of the picture surface, and a spherical lens mounted in each aperture For imaging the picture surface and the light translating element each upon the other, M -aid apertures ami lenses being so arranged that upon rotation of the disk the lenses pass successively between said surface and said element, and successive images of the light translating element traverse the pic- 65 lure surface by adjacent parallel paths. 2. In continuation, a stationary light translating element, and a scanning device consisting of a rotatahle disk interposed be- tween the said element and a plane to be 70 scanned, said disk being provided with a plurality of apertures of large dimensions as compared with an elementary area of the scanned plane, and a lens mounted in each aperture, said apertures and lenses being so TS arranged that upon rotation of the disk the lenses will pass between said plane and said element and successive images of the light translating element traverse the plane by adjacent parallel paths, 80 In testimony whereof 1 have affixed my signature, CHARLES FRANCIS JENKINS. Oct. 8, 1929. rLD *T_D 1 C. F. JENKINS HELICAL. DRUM SCANNER Filed June 13, 1938 1,730,976 M ^pji^Ji^ ft. ex-g- " *-*^ ^ . gJSy -nvvriji @JL«sU<« «>U~_~^ W&-": Llffnii^u Patented Oct. 8, 1929 1,730,97G UNITED STATES PATENT OFFICE CHARLES FRANCIS JENKINS, OF WASHINGTON, DISTRICT OF COLUMBIA. ASSIGNOR TO JENKINS LABORATORIES, OF WASHINGTON, DISTRICT OF COLUMBIA, A COHi'ORA-- TION OF THE DISTRICT OF COLUMBIA HELICAL DRUM SCANNER Application filed June 13, 1928. Serial No. 255.015. ;u 20 is This Invention relates to radiovisors, i. e., ratus for the reception of motion pic- ■ ; i : ' ■ I l ■ - dio, and has for its prin- cipal object simple, inexpensive apparati tana!] size, and producing a relatively large i :>f superior quality. ■etofore the generally employed method for the ■ n of radio vision, radio mo\ re of a large with a plurality of scanning holes therein arranged in a spiral. Such a mechanism i'-- limited by the dimensions of the apparatus itself, for example — liming 48 lines to the pid scan- 15 ning disc two feet in diameter produces a pic inch square. For a picture two inches square with the same number of lines pei* picture, requires a disc four feet in iameter, and an enormous increase in the power cf J he motor required to drive it at speed, an increase equal to the ninth power of se in speed. Reduced to merchan- dising terms, this means a device impractical use in (he average home. A still further limitation of the disc method ofsc that the whole picture an the surface scanned is lighted simultaneously, and, therefore, requires a radio power ampli- fier (many times greater than a method so which consists of hut a small glow area). Thi >■ amplifier required still further limits Hie ;i ility of the apparatus for the average home, Eor it can id be atta e l' the usual two-stage amplifier radio The employment of a drum as (he scanning ided in the present invention, is without the limitations cited above, for ex- ample, the picture may be increased by (1) an meres e to the speed of rotation; and/or (2) an increase in the diameter oft! ' urn; and/or (3) a lesser increase in both. Among its further advantages, incident to the above, is that the scanning means is very ht, with moderate peripheral speed, and. 45 therefore, requires but a small motor. The scanning apertures, in the drum I, are all equi-distant from each other, and, therefore, distortion due to varying spa apertures in the di e method, is en- 50 tirely eliminated. 5,. 40 r,-. Also, with this drum method of scanning, "in of the scanning apertures lighted independently by its own par- r glowing target, which results in a lonomy of current required for light - ■ picture. With this and other objects in view, the invention consist- of the novel combination lements herein described, illustrated in the. drawings, and pari icularly pointed out in eo MIS. i he drawings, Figure 1 is a top view of the drum : Figure 2 an end view thereof; and Figure 8 : sectional view of the lamp eni- herewith. In the figures, A is the scanning drum; B auning apertures therein arranged in a irn helix; C the lamp which encloses the glowing targets 1 , C 2 , C 3 . and C*. Between the lamp and the inner periphery of the drum lies a funnel structure V, divided hin part'' ' into four parts oi tions. The small end of. each section of this multiple funnel structure lies over its particu- !ight target. The larger end has an opening in length equal to the circumferential separation of the scanning apertures, and a width equal to the helical separation of (he holes beginning and ending the helical turn. •■eft > re. the light from each target is confined to the illumination of bill a single helical turn of the scanning apertures. Again, as the mouth of the funnel is only as wide as the circumferential separation be- i ween any two scanning apertures, the result is that but a single aperture is illuminated at any one moment As the generally accepted method of scan- ning in receiving instruments is so well known 90 to those skilled in this art, a description of ation in meticulous detail is not be- lieved necessary. In general, however, the method consists, first, in turning the scanning drum as many times per picture as there are helical turns of the circumferential line of scanning aper- tures; second, lighting the glow targets or light sources one at a time in synchronism with each rotation of the drum, for example ioo 65 70 75 80 85 -16- wOTE: The material wed in this the«i=> wa" obtained from Dr. C. Franc i 6 * Jenkin« himself; hi*> "pcrpt'iry, •'vteil Almnnd Windridge and the intent Offi- ce* of P. q ingpr. The writer greatly RT>rreciate* their kind help and a^netance.