O O I^ T E Ts^ T S . 



Page. 



General statement 5 



I'revious tide-predicting machines 10 



British tide predictor No. 1 10 



British tide predictor No. 2 10 



British tide predictor No. 3 11 



British tide predictor No. 4 11 



British tide predictor No. 5 11 



The Ferrel or United States Coast and Geodetic Survey tide-predicting 



machine No. 1 12 



United States Coast and Geodetic Sur^'cy tide-predicting machine No. 2 13 



Description of the machine 15 



Distribution of motion 16 



Dial for months and days 16 



Connecting shafts 17 



Dimensions of parts 17 



Durability of bearings 19 



Speeds of components .• 19 



Gear wheels 20 



Releasable gears " 20 



Arrangement of components 21 



Harmonic motion of pulleys 22 



Component cranks 22 



Chain pulleys 23 



Amplitude scales 23 



Arrangement of components in front frame 24 



Summation chain 24 



Height chain 25 



Height scales : 26* 



Time chain 26 



Paper-feeding mechanism 27 



Base-line pen ....'. 28 



Curve pen 29 



Scale of the tide curve 29 



Tide curve 30 



Automatic stopping device * 30 



Speed of machine 31 



Temperature error 31 



Accuracy of the machine 32 



Amplitude unit 33 



Table A 32 



Table B 34 



Table C 35 



3 



