Lighthouses can be identified by their basic design characteristic. Lighthouses were built using many different techniques to match the environments they needed to stand up to. Some lighthouses were built on cribs in the middle of the water, rocky out cropping's or on high sandy bluffs for example which required different construction techniques. They also varied in many cases due the to local contractors who constructed them.
Light towers themselves can be round, pryamidal, skeletal, conical or square/integral for example. These terms describe the towers you typically see in Michigan and other areas. Other types seen on the ocean coastal regions might include screw pile for example. These were lighthouses built in the middle of a bay on a rock and were anchored by screwing large steel screws into the rock or ocean floor to secure them down. Other types also exist but we will concentrate on the styles found in Michigan.
Round tower lighthouses are typically built of brick and may or may not be encased in a steel shell for protection. They may be large or small. A large example of a round brick one is South Manitou Island. A steel encased brick tower would be Big Sable Point and small steel tower would be Manistee Pierhead light. All are round in construction but use either brick or steel to finish them off. These towers are typically painted.
Pryamidal lighthouses are constructed of wood or steel and are in the shape of a pryramid. North Manitou Island Light which was washed away in a storm and Manistique Breakwater light are examples of this type of construction. This style was not used as much as others were. Canada used this style frequently. These could be separate towers from the keepers dwelling, connected or integrally built into the house. Some other examples are Munising an Ontanogon pierhead beacon lights.
Skeletal lighthouses are those who use a steel skeleton framework to support the light on top. Only a few were constructed of wood. Whitefish Point and South Fox Island are examples of steel skeletal framework lighthouses. These were designed to have little wind resistance and provide a solid framework.
Conical lighthouses can be classified similar to Round lighthouses. If the light tower gets narrower at the top then you can classify it as conical. An example would be Tawas Point or Point Iroquois lighthouses. Keepers typically passed through a small building or entrance room to the tower before climbing it. This entrance room could be connected to the dwelling or be separate form the dwelling all together..
Square/Intergral lighthouses are one with the tower built into the house and are square in design. Examples of this would be Round Island in Lake Huron, Big Bay Point on Lake Superior or Copper Harbor. Some were duplexes where two keepers families lived while others such as Round Island and Copper Harbor were single family dwellings.
Schoolhouse lighthouses were constructed similar to an old schoolhouse and thus the name. Examples would be Copper Harbor, Harbor Point and Grand Island North lighthouses. The house is typically all brick with an integrated tower built into the keepers dwelling. This was a common style. Others were designed with wood such as Old Mission Point. It was a simple design and was used frequently in the Great Lakes and was cost effective for harbor lights.