It is judicially settled that ``The details with which the
exemptions in this Act have been made preclude their enlargement by
implication'' and ``no matter how broad the exemption, it is meant to
apply only to'' the employment specified in the statute. Conditions
specified in the language of the Act are ``explicit prerequisities to
exemption.'' Accordingly, it is the well-established rule that
exemptions from the Act ``are to be narrowly construed against the
employer seeking to assert them'' and their applications is limited to
those who come ``plainly and unmistakably within their terms and
spirit.'' An employer who claims such an exemption has the burden of
showing that it applies. See Wirtz v. Lunsford, 404 F. 2d 693 (C.A. 6);
Addison v. Holly Hill, 322 U.S. 607; Maneja v. Waialua, 349 U.S. 254;
Phillips v. Walling, 334 U.S. 490; Arnold v. Kanowsky, 361 U.S. 388;
Mitchell v. Kentucky Finance Co., 359 U.S. 290; Walling v. General
Industries Co., 330 U.S. 545.
