No. 62. Hardness and Durability Testing of Metals.

No. 63. Heat Treatment of Steel.—Hardening, Tempering, Case-Hardening.

No. 64. Gage Making and Lapping.

No. 65. Formulas and Constants for Gas Engine Design.

No. 66. Heating and Ventilation of Shops and Offices.

No. 67. Boilers.

No. 68. Boiler Furnaces and Chimneys.

No. 69. Feed Water Appliances.

No. 70. [Steam Engines].

No. 71. Steam Turbines.