Those two books (both by Kerksis & Dickey) have entirely different content. Notice the difference in the titles ...specifically, "Field" artillery and "Heavy" artillery projectiles.
If I recall correctly, the K&D Field Artillery Projectiles book was published in 1968, and their Heavy Artillery Projectiles book in 1972.
At the time of the civil war, there were three basic Classes of artillery:
Field Artillery
Siege-&-Garrison Artillery
Heavy Artillery
"Field" refers to cannons which were lightweight enough for the army to haul around on frequently-muddy roads without great difficulty (during "campaigning in the field"). "Heavy" refers to the huge cannons whose enormous weight made them impractical to frequently haul from place to place ...and therefore they were emplaced in permanent fortifications such as river and seacoast defense forts.
The "middleweight" class, called Siege-&-Garrison artillery, referred to cannons which were heavier than the Field calibers, but were still light enough for the army to use if they did not need to be moved very often ...such as, during the long-lasting siege of a city. Examples of Siege-&-Garrison artillery are 30-pounder Parrott Rifle, 32-pounder Howitzer, and 8-inch mortar.
Regards,
Pete