53 STAT.] 76TI CONG., 1 ST SESS.-CHS. 128 -131 --MAY 12, 1939 the pneumatic-tube service, would have progressed had his original appointment as a substitute been made to grade one. Substitute service shall be computed from the date of original appointment as a regular classified substitute, and the salaries of the employees shall be fixed accordingly upon the date of their advancement to a regular position under section 116 of this title. Any fractional part of a year's substitute service, rendered after the enactment of this sen- tence, shall be included with his service as a regular clerk, garage- man-driver, driver-mechanic, or general mechanic in the motor- vehicle service, or employee in the pneumatic-tube service, in deter- mining eligibility for promotion to the next higher grade following appointment to a regular position." Approved, May 12, 1939. [CHAPTER 129] AN ACT To provide a differential in pay for night work to pneumatic-tube-system em- ployees in the Postal Service. Be it enacted by the Senate and House of Representatives of the United States of America in Congress assembled, That the Act entitled "An Act to provide a differential in pay for night work in the Postal Service", enacted May 24, 1928 (U. S. C., 1934 edition, title 39, sec. 828), is amended by striking out the words "motor-vehicle service" and inserting in lieu thereof the following: "motor-vehicle and pneumatic-tube services". Approved, May 12, 1939. [CHAPTER 130] AN ACT May 12, 1939 [H. R . 4785] [Public, No. 74] Postal Service. Differential in pay for night work, in- clusion of pneumatic- tube-system em- ployees. 45 Stat. 725. 39 U. S. C. §828. May 12, 1939 To extend the provisions of the forty-hour law to pneumatic-tube-system employees 1[. R . 4786fi in the Postal Service [Public. No. 75] Be it enacted by the Senate and House of Representatives of the United States of America in Congress assembled, That the first sec- tion of the Act entitled "An Act to fix the hours of duty of postal employees, and for other purposes", approved August 14, 1935, as amended, is further amended by striking out the words "motor- vehicle service" and inserting in lieu thereof the following: "motor- vehicle and pneumatic-tube services". Approved, May 12, 1939. [CHAPTER 131] JOINT RESOLUTION Authorizing the President to invite other nations to participate in the Sacra- mento Golden Empire Centennial commemorating the one-hundredth anni- versary of the founding of Sacramento by Captain John A. Sutter. Resolved by the Senate and House of Representatives of the United States of America in Congress assembled, That the President of the United States is authorized to invite by proclamation, or in such manner as he may deem proper, foreign nations to participate in the Sacramento Golden Empire Centennial to be held at Sacramento, California, from May 1, 1939, to September 10, 1939, inclusive, for the purpose of properly commemorating and observing the one- hundredth anniversary of the arrival in California, at the confluence of the American and Sacramento Rivers, of John Augustus Sutter, a Swiss adventurer, and the founding by him, through the estab- Postal Service. Forty-hour law pro- visions, extension to pneunmatic-tube- system employees. 49 Stat. 650. 39 I. .SC., Supp. IV, § 832. May 12, 1939 [H. J. Res. 221] [Pub. Res., No. 151 Sacramento Golden Empire Centennial. President requested to invite participation by foreign nations. 741 Computation.