When the movie magatheria invented the double feature to lure pedestrians, they cooly set out to produce cheap, third-rate pictures to go along with major efforts. Gradually temptation overcame, and theatres have taken to showing two pot boilers at once. Such a disaster has overtaken the Paramount and Fenway this week. "Isle of Fury" and "The Captain's Kid" are Trivial, minor affairs, each adequate as an aperitif to an important movie, but in combination they do not approximate a full meal.

"Isle of Fury" is a scenario writer's nightmare, containing every possible dramatic situation with the exception of the World War. Margaret Lindsay and Humphrey Bogart, he of the underworld voice, are the leading players in a series of adventures on a Pacific island. A mysterious though good-looking stranger is shipwrecked into a group of pearl divers and fugitives from justice and, or civilization. Among the other thrills are an underwater fight with an octopus, a pearl robbery, a shooting, and an unveiling of a G-man. Humphrey Bogart is convincingly hardboiled and confident as he drives the natives to work in the dangerous oyster beds and strides surely through perils both criminal and amorous. Based on Somerset Maughm's "Three in Eden", the movie is a good, unpretentious thriller and enjoyable in the same way as a wild western.

Not even the Warner Bros. publicity department could straightfacedly recomend "The Captain's Kid", for the adjectives in the advance notice begin with "it is said to be". Miss Sibyl Jason is one of the cute baby actresses who set back the public with winsome appeal. Although more natural and healthy than la Temple, she is ill served by her studio. The great Duse herself would fail to delight if continually coddled by an old sea captain like Guy Kibbee. A summer resort is the scene of mild melodrame concerning a pirate treasure hunt and two gangsters up from the city. Kibbee moves pleasantly in and out of jail and spends every fifth minute kissing little Jason.