Perhaps you have never heard of the survey of the USA/Canadian border along the 49th parallel? Or the survey of the Manitoba/Saskatchewan border? Or just about any major land survey. You are blowing smoke and you know it.
The entire English railroad, the Great Pacific Railway, the Great Canal of China, the Suez Canal etc etc...
J.C. Bourne in his book, “The History of the Great Western Railway” stated that the entire original English railroad, more than 118 miles long, that the whole line with the exception of the inclined planes, may be regarded as level. The 1862 British Parliament Session which approved its construction, recorded in Order No. 44 for the proposed railway, “That the section be drawn to the same HORIZONTAL scale as the plan, and to a vertical scale of not less than one inch to every one hundred feet, and shall show the surface of the ground marked on the plan, the intended level of the proposed work, the height of every embankment, and the depth of every cutting, and a DATUM HORIZONTAL LINE which shall be the same throughout the whole length of the work.”
“In a long line, like that of the Great Pacific Railway, extending across North America, the supposed curvature would, of course, be proportionately great, extending to many miles in height, but not one inch was allowed by the engineers for curvature during the whole course of the construction of that vast line of Railway. And, if we think of it, how could it be otherwise? All Railway metals must, of necessity, be straight, for how could any engine or carriage run with safety on a convex surface?” -David Wardlaw Scott, “Terra Firma” (125)
Let those who believe it is the practice for surveyors to make allowance for ‘curvature’ ponder over the following from the Manchester Ship Canal Company (Earth Review, October, 1893) ‘It is customary in Railway and Canal constructions for all levels to be referred to a datum which is nominally horizontal and is so shown on all sections. It is not the practice in laying out Public Works to make allowances for the curvature of the earth.” -Thomas Winship, “Zetetic Cosmogeny” (23)
The Great Canal of China, said to be 700 miles in length, was made without regard to any allowance for supposed curvature. -David Wardlaw Scott, “Terra Firma” (134)
“The distance between the Red Sea at Suez and the Mediterranean Sea is 100 statute miles, the datum line of the Canal being 26 feet below the level of the Mediterranean, and is continued horizontally the whole way from sea to sea, there not being a single lock on the Canal, the surface of the water being parallel with the datum line. It is thus clear that there is no curvature or globularity for the whole hundred miles between the Mediterranean and the Red Sea; had there been, according to the Astronomic theory, the middle of the Canal would have been 1,666 feet higher than at either end, whereas the Canal is perfectly horizontal for the whole distance.
Engineer, W. Winckler, wrote into the Earth Review October 1893 regarding the Earth’s supposed curvature, “As an engineer of many years standing, I saw that this absurd allowance is only permitted in school books. No engineer would dream of allowing anything of the kind. I have projected many miles of railways and many more of canals and the allowance has not even been thought of, much less allowed for. This allowance for curvature means this - that it is 8” for the first mile of a canal, and increasing at the ratio by the square of the distance in miles; thus a small navigable canal for boats, say 30 miles long, will have, by the above rule an allowance for curvature of 600 feet. Think of that and then please credit engineers as not being quite such fools. Nothing of the sort is allowed. We no more think of allowing 600 feet for a line of 30 miles of railway or canal, than of wasting our time trying to square the circle”