straight core transformers and chokes

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: dgoodfellow-at-highstream-dot-net 

I am contemplating the construction of a straight core transformer. I read 
an old Tesla coil how-to book from the 20's that was on microfilm in the 
New York public library a long time ago. My hand written notes from 20 
years ago are as follows:

"Pieces of 18" long #20 or 22 B&S gauge iron wire, stuff as many as will 
fit into an iron pipe less than 2" in diameter. Throw into a coal fire and 
leave until it dies out. Remove iron wire, clean, and coat individually 
with shellac. Push back into pipe, then push out the bundle slowly, wrap 
with cotton bandage, 1" wide, and coat with shellac.

The builder was to then create a number of thin wooden discs 6" in 
diameter, with a hole cut in the center large enough to slide them onto the 
bundle of iron wire. The primary and secondary windings would be wound 
between the disks. The disks are to be 3 1/4" apart along the bundle of 
wire. The transformer would have 4 sections, each 3 1/4" wide, with a 1" 
gap in the center, between the 2 primary windings and the 2 secondary 
windings. Just imagine 4 donuts stacked on a paper towel roll and you get 
what this is to look like.

"Primary is wound in 2 sections with #12 B&S double cotton covered wire, 2 
1/2 lbs. Wind 60 layers, with a turn of paper between each layer."

The next section is made essentially the same. For some reason, I didn't 
write down the gauge of the secondary wire, or how many turns were 
required. I do remember that it was a lot of layers.
The book claimed that a straight core was superior to a closed iron core. 
This, I wrote down word for word...

"A straight core is always best to use; for on the fall of the current from 
its maximum value to zero, the magnetic flux falls from its maximum value, 
not to zero, but to a value which depends on its residual magnetism. The 
residual magnetism in an open circuit is much less than in a closed 
magnetic circuit so that when the current suddenly becomes zero, the 
magnetic flux drops lower in an open circuit than in a closed one. As the 
electromotive force in the secondary is proportional to the fall in the 
magnetic field, it is greater with a straight core than with a closed 
circuit of iron"

So here's my plan.... I see that Mcmaster Carr sells iron wire, in 1 foot 
lengths, or rolls. It is high carbon wire. I want to take a bundle, varnish 
each piece, stuff it into a thin walled phenolic tube, cut the wooden disks 
which will divide the primary and secondary windings, and start winding a 
transformer.

I would like to hear from anyone that has knowledge of transformer design 
parameters to evaluate this, and submit your thoughts on this type of 
transformer before I start building it. Any guess on the gauge of wire for 
the secondary? How many turns?
Does anyone recognize this book? It was titled something like "How to build 
and test a complete Tesla coil" It also described the construction of a 
high voltage rectifier by filling a fish tank with battery acid and sinking 
an array of plates made of iron and aluminum,  similarly to a car battery.

Thanks to all who reply,
Dave Goodfellow