LXXXIV. DISCUSSION. 
most unexpected closes on a line of levels most roughly done, 
while at other times when accuracy was the first consideration, it 
had been a most difficult matter to obtain a reasonable close. 
Except in flat country where equal sights could be obtained, it 
might be said to be impossible to level from morning to night and 
obtain anything like favorable results, as the refraction element 
entered so largely into all observations made in the densest part 
of the atmosphere. As all the work done by the Water Conser- 
_ vation Department, was by contract, it seemed natural to infer 
that all the daylight would be utilised when possible, and thus 
when very good closes were made the errors must have compensated 
ina very fortunate manner. In the survey of India, where the 
most elaborate precautions were taken to insure accuracy in 
levelling, and one mile to two miles a day was regarded as good 
work, where staves were standardized at the beginning and end 
of each work, and were marked as being one-ten-thousandth of a 
foot too long or too short, an error of one inch in 356 miles was 
looked upon as an unusually good close. 
The error in No. 3 line of levels, referred to in Mr. McKinney's 
paper, was equal to one inch in 2324 iniles, which might be taken 
as comparing very favorably with the best work by the best men 
in the older countries of the world. The average daily rate of 
progress attained by the surveyors on this work would have been 
a valuable addition to the paper, and also a statement of the 
distance between bench marks on the routes. It was only by 
cross levelling between intermediate bench marks on the various 
routes, that a true check on the work could be obtained, and this 
would probably be carried out as settlement extends, and the 
serious work of water conservation and irrigation is undertaken. 
That such work will be undertaken at an early date, must be the 
wish of all who have the interest of this country at heart. The 
most casual observer, who travelled in the inland plain country 
was struck with the wonderfully luxuriant growth, where water 
was judiciously applied to the apparently useless soil. The val 
able information obtained thus far by the Water Conservation - 
