Vegreville egg
The Vegreville egg is a giant sculpture of a pysanka, a Ukrainian-style Easter egg. The work by Paul Maxum Sembaliuk is built of an intricate set of two-dimensional anodized aluminum tiles in the shape of congruent equilateral triangles and star-shaped hexagons, fashioned over an aluminum framework. The egg is long and three and a half stories high, weighing in at . It is the second largest pysanka in the world. The biggest one was built in Kolomyia, Ukraine in 2000.
Gwiazda Polski
Its bag was made in Legionowo of Japanese silk covered with rubber, and the 500-kilogram gondola was constructed by engineer Jan Alfred Szal. Gwiazda Polski was an impressive construction. Its height was 120 meters, capacity of the bag was 124,700 m³, size - 12,300 m², and weight - 1500 kg. As costs of this undertaking were high, a special stamp, depicting the balloon was issued by the Polish Mail. Also, individual donors, including members of the Polish community in USA, helped with funding. 
The violet-color stamp was issued on September 15, 1938. Its market price was 75 , but it was sold for 2 zlotys, with the 1.25 zloty surplus being donated to the Scientific Council of the Flight. Altogether some 65,000 such stamps were printed, and the mail office in Zakopane used specially made seals with depiction of the balloon on all letters and postcards in these days. Today those stamps are scarce, their prices reach up to 200 zlotys 
Curiously enough, the balloon, which had been planned to land somewhere in Volhynia, carried several pieces of mail, sent to Łuck, Rowne and other places. After the fire, the Polish Mail sent those letters in the ordinary way sealed with information that the flight had not taken place due to fire.