[PRCo] Re: PennDOT historical maps (was: West Penn Street Car??)

[Fred Schneider]

But remember, Don, that the USGS maps are all plane table mapping  
technology.  The aerial surveys of today are a whole lot more  
accurate in some ways.

On Jun 25, 2008, at 9:52 AM, Donald Galt wrote:

> On 25 Jun 2008 at 8:31, Edward H. Lybarger wrote:
>
>> There was a lot of sloppy mapmaking in those days.
>> But the fact that it was
>> done at all with the available tools is
>> remarkable.
>
> Yet, the best mapmaking of the early XX century is stunning, like  
> any work that
> an artist takes seriously. By and large, USGS topos at 1:62500 and  
> 1:125000 are
> exquisitely engraved and highly accurate (surveying may have been  
> harder than
> it is nowadays, but was not to be sniffed at). They can easily  
> stand being
> blown up to double size, thereby yielding even greater detail.
>
> And that's just the US. The best of European government mapping of  
> that era is
> if anything even better.
>
> Of course, GIGO as you say. It's not that unusual with slightly  
> earlier 1:62500
> maps to find railways crossing contour lines back and forth like  
> roller
> coasters.
>
> That rendering of the Charleroi interurban is an example of  
> careless freehand -
> quite possibly taking a smaller-scale map as its source. A similar  
> example is
> on the Cambria County map, where the Southern Cambria line across  
> country to
> Ebensburg and Nanty Glo appears drawn in two or three strokes.
>
> Don G
>
>