High altitude balloons of that day were not of the size and volume of those sent aloft in the present. The envelopes of the helium filled "Skyhook" type balloons were not as strong back then. The seams of the mylar could not be bonded as well as they are now so to get the volume of helium needed to get these balloons to a level where they would expand to hundreds of feet in diameter at altitudes of 75,000 to 100,000 feet while supporting heavy payloads. In 1954 it was more likely that the balloons would get to about 100 feet in diameter at 75,000 feet and certainly well below that expansion at 14,000 to 19,000 feet.
Since this subject came up in another case some years ago I had discovered specs for the helium balloons [the US military WS-119L (128TT)] of that period (1953-54-55) and that these balloons did not exceed 128 feet in diameter at 100,000 feet. Assuming a size of perhaps 70-80 feet across at 19,000 feet the distance now becomes a factor where acuity is concerned and hardly the arresting phenomenon the flight crew observed.
Nova Scotia, Canada
[Don LEDGER is a pilot and a well-known UFO researcher. He authored two books on UFOs and one on the investigation of a 1998 airliner crash off the coast of Novia Scotia that killed 229 people.]