H. A. Hazen — Prevailing Wind Direction. 



463 



and 14*3. If we should have 5 and 14'3 it would be much 

 better to multiply the whole number by 10 and enter the 

 table with 50 and 143, i. e., the larger the numbers used 5 

 provided they are within the limits of the table the easier the 

 computation. , 



The instructions in this paper have been prepared by Mr. E. 

 A. Clark. 



June 7, 1887. 



Tens. 

 

 10 

 20 

 30 

 40 



50 

 60 

 70 

 80 

 90 



100 

 110 

 120 

 130 

 140 







0-0 



7-1 



14-1 



212 



28-3 



35-4 



42-4 

 49-5 

 56-6 

 63-8 



70-7 

 77-8 

 84-9 

 91-9 

 99-0 



Table I. — Multiples of cosine 45° (-7071). 



Units. 



1 

 •7 



7-8 

 14-8 

 21-9 

 29-0 



36-1 

 43-1 

 502 

 57-3 

 64-3 



71-4 

 78-5 

 85-6 

 92-6 

 99-7 



15 

 22 

 29 



36 

 43 



50 

 58 

 65 



72 

 79 

 86 

 93 

 100 



3 



2-1 



9-2 



16-3 



233 



30-4 



72-8 

 79-9 

 87-0 

 94-0 

 101-1 



8 37-5 38 



8 44-5 45 



9 51-6 52 



58-7 59 



1 65-8 66 



73 

 80 

 87 

 94 

 101 



5 



3-5 

 10-6 

 17-7 



24-7 

 31-8 



38-9 

 46-0 

 530 

 60-1 

 67-2 



74-2 

 81-3 

 88-4 

 95-5 

 102-5 



6 

 4 

 11 

 18 

 25 

 32 



39 

 46 

 53 

 60 

 67 



75 

 82 

 89 

 96 

 103 



7 



4-9 

 12-0 

 19-1 

 26 : 2 

 33-2 



75-7 

 82 7 

 89-8 

 96-9 

 103-9 



5-7 

 12-7 

 198 

 26-9 

 33-9 



764 

 83-4 

 90-5 

 97-6 

 104-7 



9 Tens. 

 '4 

 10 



6 40-3 41-0 



7 47-4 48-1 48 



7 54-4 55-2 55 



8 61-5 62-2 62 



9 68-6 69-3 70 



77 

 84 

 91 

 98 

 105 



20 

 30 

 40 



50 

 60 

 70 

 80 

 90 



100 

 110 

 120 

 130 

 140 



150 106-1 106-8 107-5 108-2 108 9 109-6 110-3 1110 111-7 112*4 150 



In using this table find the tens and hundred of the number to be multiplied 

 by cos 45° in the left hand column and the units in the upper horizontal line. 

 The product will be found at the intersection of the horizontal and vertical lines 

 from these. For example, 148 x cos 45° at the intersection of 140 and 8 we find 

 104 7 answer. 



