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Hence, .generic adoption, for aerophotogrammetric mapping, of tolera.nces used porordinary mapping, does not permit evaluation of the quality of work in relation toits different technique of execution.

Following, for lack of profound studies on the subject, the conditions of ,accept­ability established for normal surveys, it seems necessary to intensify controls andto ba.se on these a.n essential part of the complex operation of approval.

These controls, moreover, can efficiently- serve for a genera.l gauge of the exe­cution of altimetry on a map.

At present, altimetric tests for approval are executed, as a rule, in localizedparts of the map. The procedure is as follows: lines are drawn on the map approxi­mately normal to contours; distances between intersections of this line with the con­tours are accurately scaled and compared wi th a profile of this same line ma.de on theground. The difference between the two profiles must remain within the limits of theprescribed tolerance. The effect of irregular slopes between contours is largelyvitiated by' taking the ground profile at the scaled distance of contours.

There SIre objections to this method, both technical and economics.l, which leavethe technique of alt-imetrie approval a. problem for further study.

* * * * *The Cadastral Administration, realizing the importance of aerial Photogrammetry,dedicates more than interest to the studies of various technical problems, and themost attentive care in selecting personnel to carry out the work. It desl~es notonly to meet the difficult problems confronted but also to absolve the duty thatfa.lls to it as a great organism of the state; a dutv of contributing worthily to thenew seienee in the land of its distinguished precursor, Ignatius Porro.

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PROGRESS OF COAST ~ GEODETI C SURVEY ~LENS c.A.MERALieutenant O. S. Reading

The Coast & Geodetic Survey nine-lens aerial camera (News Notes No. 5 May-June1935) together with its transforming printer has recently been delivered by theFairchild Aerial Camera Corporation. The camera is now undergoing optical adjust­ments and tests at the offices of the Coast and Geodetic Survey in Room 1235 - Com­merce Building in Washington. It is hoped that it will be possible to take sOmetest photographs and publish preliminary results in time for the next issue of NewsNotes. Members of the Society are welcome to inspect the ca~era and the methods ofadjustment when in Washington.

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~R-MAPPING EXHIBITAT THE

AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE MEETINGST. 1&Y.!§, .M.Q., DECEMBER 30, JANUARY ~

Arthur J!.. J~ambert, a.St. Louis, Mo. Engineer Office,

U. S. War Department.

An unusual opportunity to gauge public interest in air-surveving methods was af­forded at the recent exposition of the American Association For The Advancement ofScience in St. Louis, December 30th through January 3rd last.

The Missouri Photographic Society, charged with getting up a display dealing withscientific aspects of its SUbject, reouested the writer's cooperation in furnishingsome photographs..;,from-the-air material snd it was thought that demonstrations a.nd

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explanations of the use to which this material was put might be of public interest.Realizing that this might be an excellent opportunity to display some of our wares

Lieut.-Col. P. S. Reinecke. Corps of Engineers. U. S. Armv. District Engineer incharge of the St. Louis District Office, took a long chance and authorized the writerto go ahead.

About two hundred square feet of floor space was promised and in a spirit of dig­nified elation we looked about for interesting specimens to display.

So elated was our sponsor over the rne,terlal we obviously had at our disposal thatwe swallowed the hook. line, sinker and all. And 1t was not until some tirne a.fter hehad departed that we realized that the courteous gentlemen who represented the saidsociety had neatlY and gracefully outmanouvered us at our own game. From the instanthe gained our unqualified assent he had shifted a large slice of responsibility fo'rthe forthcoming photographic exhibit to other shoulders.

Confidentially speaking~ what the writer does not know about photogrammetry wouldfill several sizeable volQmes, and this awful fact hit us amidahips with a sickeningthud about ten minutes 'after he had committed himaelf to a five-day continuous per­formance in competition with many ofCthe countrySs leading organizations and ex­ponents of science.

On taking atock we found that we had plenty of single-lens vertical photographs,used in mapping areas on the Mississippi River and its important nearQY tributaries.We also had some old mosaics made frdrn river strips and various other adjuncts andbits of paraphanalia, including some stereoscopes and the pride of the office -- thePro.iectograph, an instrument for projecting diapositive contact prints or other ma.t­ter to any desired scale, designed, made and built entirely by local talent. On ourpreliminary lay-out sketch it occupied the central space in the eL~ibit and was to bethe principal item on display. We later called it the "Elephant~ when careful '!lee.­l'!urements showed that, instead of fHUng nea,tly into the space provided as shown onthe prelimi~ary diagram, it was slightly over eleven feet long and would hardly fitinto the standard ten-foot depth booth without considerable embarrassment.

This discovery further convinced us that we had bitten off considerably more thanwe could chew, and we resolved right then and there that if by any turn of fate wemight survive the crushing blow to our pride that the impending fizzle seemeddestined to produce. we would hence'forth attend such affairs as sightseers and leavethe job of exhibiting severely alone.

After a sleepless and restless night on or about the evening of December 1st,1935 we came across an allusion to the old saying that a one-eyed man was a king ina countryof the blind. And we then recalled a recent conversation with a dis­tinguished professor of engineering at a local university - a gentleman who in thedim past found little difficulty in correctly appraising ingenious classroom effortson the part of yours truly to conceal 'ignorance. It had developed that he knewpractically nothing of air-surveying methods, for he listened with considerable at­tention and interest to the description of some comparatively simple methods usedin our office.

Other conversation of similar i~port were then recalled in more or less pro­fusion. some with eminent professional men, educators and engineers and we were againimpressed wi th the, fact that at the outset of our dissertations very few had any con­cept at all of the.methods used in either taking or using air-photographs fortopographical purposes.

Logic came to the rescue. VIe. therefore. reasoned that if' the prepondera,te pro­portion of professional persons in these exalted strata of human intelligence wereSO meagerly informed as to methods and technique of photogrammetry -- even to thepoint of confusing a ~otoKLammetris~ with the perambulating side-walk artist whotakes, developes, mounts and delivers a recognizable 11ke~ess of a Willing subject forthe customary fee of one di~e -- that the ignorance of the gr.eat mass of exhibithounds, particularly when the admission was free~ must De abysmal.

l

Comforted by these r9flections and confident, unless a real photogrammetristtrom out of tOl.l.'11 wit.h ...hom we were unacquainted chancQd by to gum the works, we feltthat we could. take ad'18nta&e of this lack of information if necessa.ry and, photo­grammetically speaking, get away with murder.

We accordingly began perfecting our pl~s.

Another fact then dawned to bring additionsl confidence.Inasmuch as we had been invited to exhibi t and no charge was to be made for the

space we occupied, we felt it would be possible to quietly and unostentatiously ex­pand when the time came and get the "elephant" into the "donkeyQ an stall. We arespeaking metaphorically and not politically: .

Another illuminating idea!It suddenly occurred that we might get help from friends.So out went a number of S.O.S. calls.The prompt and generous responses, that kept coming in for the following three

or four weeks, gradually turned our remaining spells of panic and that-empty-feelinginto growing enthusiasm.

Capt. Rumaggi and his obliging cohorts in Dayton sent us a most interestingselection of photographs and Lt. Reading and Mr. Hawley of the Coast and GeodeticSurvey loaned an interesting five-lens exhibit on the mapping of San Diego Ba7. Dr.Bauer·of the Carl Zeiss Company and Messrs. Eliel and Polley of the Fairchild Surveysresponded generously with pictures of plottir~ machines, planes, cameras and equip­ment, including interesting stereo-oblicues and multi-lens mosaics.

To assist in our technical demonstrations we prepared a few simple diagrams, il­lustrating the essentials of air-survey principles and elementary methods ra.ther thansamples of the actual work itself.

Without going into further preliminary details, let us say that assured ofsuch plentiful material all we had to think about was to wall in our space prepar~

tory to backing in the "elephant" and hanging pictures.As we are primarily interested in the photogrammet~ie aspects of the situation

we will not elucidate on the methods employed in "privately" arra.nging for the re­quired additional space, nor on the means employed to requisition certain Auditoriumproperties or the diplomatic technique exercised in rr~king certain convenienteleotrical connections, hammer in a few nails and splash on a bit of paint here andthere without offending the aesthetic sensibilities of several walking delegates whowere more interested in the preliminary arrangements than in the exhibition itself.

On Monday, December 30th, Mr. Loren Bloom, the official keeper and tra.iner ofthe "elephant", just returned from Christmas leave, loaded his charge in a largeU. S. E. D. truck, transported it to the Auditorium and seti t up in the a.mple spacethat had been provided.

At 1:0:00 A.M. the next morning we turned on the lights and waited for customers.On looking around we were struck with the many intensely interesting booths

and instinctively' felt that on the whole the exposition would be considered a suc­cess. We also confidently expected that a few visitors would stop to see our owndisplay, out of politeness if for no other reason. Then v with the initial streamthinned out, we anticipated spending the greater portions of the remaining four daysin visiting and examining the interesting things on display in~ booths.

However, such plans for making these keenlv anticipated visits in other partsof the hall soon met with unforeseen difficulties. The customers, instead ofcasually giving us the once-over as they passed by, attracted bv the large projecte~

image on the projectograph easel, photographs on the wall, mosaics casually left onthe counter or other items on display, actuallv stopped, stepped in, listened to whatwas said, and asked questions.

Unfortunately, the newspapers devoted page after page to the doings of the ~s­

societion, and this ill-timed publicity failed miserably to keep down the daily at­tendance at the e~position.

J

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The d.oors opened officially at 10:CO A.M • .daily. The originally advertised c10s­lng time was 3:00 P.M., and it was understood that there would be no night sessions.

These had ~een deemed a~ple hours for such a technical type of displa~, especiallyfor the numerous commercial exhibits, whose space was paid for. to contact any delegatewho might be inter~sted enough to stop in. look over the lay-out and sign the custo~~

blank requesting a catalogue.~ut, owing to the conspiracy of the press. the publiC in general took-an unex­

pected ,interest 1n the proceedinj?,s and neElrly ruined the whole show.The place was moderately jammed at all times. Some early risers actually sneaked

1n ahead of ti'l1e and were on hand to see lHlme dilatQrv booth attendants uncover theirwarea~ Furthermore, the official closing time was advanced to 6~OO P.M. and a nightsession held on ~ig Thursdp-y by popular recuest.

Fortunatel~ no real photogrammetrists showed u~ to call our hands and by Fridaymor~ing, when our larynxs finally gave out. Bloom and the writer had convinced hun­dreds of interested visito~ that we were personally the world's cha~pion aerial map­pers in captivity. In fact, but for our extre~e modesty, we mi~ht b~ tempted to saythat nU!l1erous -persons competent to judge, priv6.tely assured us that we had one of theMQst interesting exhibits at the exposition.

~siness wa~ so good Thursday afternoon that we had to send for help. Fox, thethird conspirator, joined us after lunch and brought a sorely needed set of fresh vocalchords. into play for the remainder of the sessions. Keeping his hat on when be firstarrived be remained incognito and mingled with the orowd long enough to get onto ourline. Then he put on his "attendant" badge and held his audiences spellbound wi thdissertations cribbed from his associates, to which he added numerous improvements ofbis own ..

~loom and I rather resented his sudden success and immense popularity with thecrowd. Fox seemed to sense this pecull~r attitude on our part, so, in the interest ofharmony we waited until he was well along on a dissertation on the stere~scope andbad arrived at that portion Qf his talk when he ~t hi~ eyes into the hood to checkup on the instruments adjustment. Then without further ado we left him in sale chargewhile we joined with, the merry throng at other parts of the building.

A.side from pUrely t,echnics.,l discussions. '918 were frequently interrogated. byuniversity professors and various teachers of sciences and, physics in both collegesand_ high schools. M~ of these sought information as to the feasibi 11 tv of incluct­l,ng courses deal1ngwith air-surveying in their curriculums g (or is it curricula?).We hope that we were not exceeding our authorities or overstepping our bo~nds too farwhen we aEsure.d several in this grou'O that various government departments, would beglad to cooperate with their institutions in this respect.

We might go on indefinitely with our reflections, but we will slow down a.nd startto end our chronicle by saying that in the forty-two hours of exhibition tim~ in­volved between three thousand and thirty-$ive hundred individuals stopped at the boothlol),g enough to f1nd out that making maps from air-photographs wa,s a most interestingand useful process. Of these, t~e majority listened intently to what was being saidand ~t least twenty-five percent of these asked questions.

Now, spe~ing COnfidentially, -- as one photogrammetrist to another g we must con­fess that though we feel we put on a most interesting display and told a lot aboutmap-making methods, we carefully avoided giVing away any of the real technical secretsof the craft. From its inception we plotted to interest and amuse rather thaninstruct. In fact, behind the entire exhibit plan lay the idea of dabbling a littlein Public Relations and getting some good publicity for the department. This. hQ~­

ever, we carefully concealed from the customers. To the very end they imagined they·were in the hands of experts. as evidenced by SUCA remarks as the followingl

"'Ie dido't know the War Department did anything like this?"wWhy do&sn't the Government bring more o.f this to our attention?"'then the tax-payers know their money 1s being spent on thingS! like this ,they

don't object so much to appropriations."After the show was over and all property had been properl~ returned or accownted

for, Bloom. Fox, and the writer were congratulating ourselves on the wonderful suc­cess we had had in arousing so much public interest in air-surveying.

But someone is always taking the jov out of life, and we were soon made to real­ize that, although our lucid ezplanations did help some. it was the general romantieinterest in the airplane and in photographs made from airplanes that wat chieflyresponsible for having made our exhibit a success.

Yes, there is still a romantic appeal to mankind's continuing conqUest o·! theair. Photography, too, is still a mysterious process to the average individual.Map-making is a respected but more or less uninteresting process. However, eomQinemap-making with the mysterious new airplane photographs and cameras and the romanticwings that can' carry them to what has so long been the unattainable heights - andyou have a combination that is capable of unli~ited imaginative appeal.

Perhaps the true import contained within this more or less facetious account ofa most interesting event is so artfully concealed that no one will suspect its pres~

ence. If so, let us sugg€S~ a further hint by quoting a remark made near the closeof the recent scientific exposition, in explanation of its widespread and somewhatunexpected popularity:

~lOO~ scientist: Misunderstanding, incomprehension, public derision, persecu­tion, poverty, etc • • . •

"99~ scientist plus l%Barnum: The· World at his feet!"

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.ill FAIRNESS 19.~M. S. Wright

Soil Conservation Service

The So11 Conservation Service, probably J1\,:>re than some of the older establishedGovernment bureaus, has been occasioned. co~s ider inconvenience and delay in theletting of cOntracts covering urgently needed aerial surveys by prospectiYe bidderswho, instead of examining the ~pecificatlons and maps within a reasonable time afterthey are received and filing at once any requests for clarification or amendment, de­laY' such requests until 8_ few days, or even hours) before the time fixed for theopenings of the bids, with a consequent pos tponement of the opening date. Whilethese amendments or revisions are so~etimes helpful in clarifying the specificationsinsofar as the bidder's interpretation is concerned, it is unfair to di stant co"Opet­itors for representatives who happen to be in Wa9hln~ton or nearby to de~ay theirrequests for consideration of proposed changes or amendments. Thi~ practice worksandefinite hardship on the remote bidd~rs who have for~arded their bids and bid bondsand who, upon receiving amendments or revisions. usually sent by wire G have to rushthro~gh revisions of their estimates and submit new bid bonds to the newly submittedbids. I t is also unfair to bidders who have made s. specie.1 trip to Washington to bepresent at the opening.

It would appea.r" that anY1:lrotests or suggestions for revisions of specificationsmight reasonably be prepared in writing and submitted at least a w~ek before the timoset for opening the bids. This would no t only give the Government a be t ter opportun­itY' to study the. sugges'ted changes, but would allow all distant and absentee bidderstime to prepare their bids and send them in by regular or air mail and would be muchmore fair to all concerned.