High Frequency Apparatus Page 229

APPENDIX PARTS AND MATERIALS. In the pages which follow, a comprehensive list of raw materials, parts, and finished apparatus is offered. This list has been prepared solely as a matter of convenience to the reader and with a view to obviating the bulk of the correspondence that inevitably results from the publication of a book of this character. The author has answered as many as twenty letters in one day, giving prices, dimensions, weights, and the manufacturer's name of this and that object after the appearance of an article, and, while it is a pleasure to answer correspondence bearing upon the actual construction or use of the apparatus described, it is discouraging and costly to typewrite a list that could just as well be printed. Hence, this appendix. The materials and instruments listed may be ordered directly from the Curtis Engineering Laboratories Company, 104 Fifth Avenue, New York City. Prices subject to change without notice. Knife Switches. Unmounted, 110-250 volts, not fused. Front or back connected (specify which). SINGLE THROW DOUBLE THROW S.P. D.P. 3 P. 4 P. Amp. S.P. D.P. 3 P. 4 P. $1.00 $1.50 $2.25 $3.00 25 $1.50 $2.30 $3.50 $4.60 1.20 1.80 2.70 3.60 35 1.45 2.20 3.25 4.40 50 1.90 2.90 4.35 5.80 75 1.90 2.90 4.40 5.80 2.90 2.20 3.30 5.00 6.60 4.35 6.50 8.70 229