TIDE-PEEDICTIKG MACHINE KO. 2. 15 



Owing to various causes it was not until February, 1910, that the 

 machine was completed, excepting as to polishing, plating, and 

 lacquermg. It was immediately put into use for predicting the 

 more compHcated tides for the 1912 and 1913 tide tables, thus afford- 

 mg opportunity for dismounting, finishing, and reassembling in time 

 for predicting the 1914 tide tables. 



DESCRIPTION OF THE MACHINE. 



The names or symbols of the components represented in this 

 machine are given in Tables B and C. 



As regards the general form of the machine, the reader is referred 

 to plates 6 and 7. The first presents a full view of the right side 

 showing a desk supporting the dial case; behind it, regarding the 

 desk end as the front of the machine, a tall frame mounted on a 

 depression m the base, called the front component frame; and behind 

 this another long and lower one, called the rear component frame 

 Plate 7 shows the front of the dial case with the dials, pointers, curve 

 sheet, pens, etc., and, looking toward the rear, the left side of the 

 component frames. This side carries the mechanism for summing 

 the cosine or height series; its parts will hereafter be referred to as 

 the height cranks, height puUeys, height chain, etc. Upon the other 

 or right side are disposed the cranks, pulleys, chain, etc., for summing 

 the sme terms of the derived or time series, hereafter designated as 

 time cranks, pulleys, chain, etc. 



A fair idea of the size of the machine as a whole is obtained from 

 the following dimensions: Horizontal distance from front edge of 

 desk to rear edge of rear base plate, 129i inches; vertical distance 

 from floor to top of front component frame, 74i inches; extreme 

 width — 1. e., width of base plates— 24 inches. 



The dial case is mounted upon an iron base 2^ feet high to permit 

 of the use of a wooden covering (the latter was not in place when the 

 photographs were taken) for the desk top. This case is made up of 

 two hard-rolled brass plates A inch thick, 19 inches wide, and 2U 

 mches high, secured to each other by six brass posts U inch diameter. 

 Ihe shafts of the hour and minute and the day and month dials have 

 their bearings m these plates (plate 9). The vertical shaft, f inch 

 diameter, runs m brackets secured to the rear plate, the intermediate 

 shalts being mounted in the same manner. 



The front component frame is made up- of two hard-rolled brass 

 plates 3^ inch thick, 24 inches wide, and 56i inches high, secured to 

 each other, 7 inches apart, by ten |-inch brass posts. 



Each of the sides of the rear component frame, of the same thick- 

 ness and material as those of the front frame, is composed of two 

 pieces joined horizontally at the medial line. The sides thus formed 

 held together 7 inches apart by fifteen }-inch posts, are 40i inches 



