May 23, 2017· attempted to return null from a method with a primitive return type (double). double,mapper . xml,, null double,,0 .
Jun 28, 2021· ：org.apache.ibatis.binding.BindingException: Mapper method 'com.dao.UserDao.getSum' attempted to return null from a method with a primitive return type (long).：1、sum()wherenull,resultType,。
Quarrying by use Of Channeling Machines. In this method, the channeling machines are driven by steam, compressed air or electricity are used to make vertical or oblique grooves or channels on the rock mass, These machines make rapidly the grooves having a length of about, 24 m, a width of about 50 mm to 75 mm and depth of about 240 cm to 370 cm.
Apr 29, 2021· The string str is a primitive. So in the moment of accessing its property, a special object is created that knows the value of the string, and has useful methods, like toUpperCase(). That method runs and returns a new string (shown by alert). The special object is destroyed, leaving the primitive …
May 26, 2020· 10 Primitive Survival Skills that Will Keep You Alive. Don't rely solely on modern technology and gear in a survival situation By Tim MacWelch ... Most methods involve a drill being spun back-and-forth on a board (reciprocation is the key to most friction methods). It can also be done with a sawing motion (again, going back-and-forth).
Apr 02, 2020· As a case in point, another study published this week in Nature journal used modern techniques to date a well-preserved skull found in a quarry at Kabwe, Zambia, in 1921.
4. Hillside Oven. An outdoor, hillside oven requires you to dig into a hillside and frame out an oven space using large, flat rocks. Build your fire inside the oven and put your food on top of the fire. Close up the front of the oven with another large, flat rock, and voila – a closed cooking space! 5. Stone Age Griddle.
Few texts concerning Egyptian engineering methods have survived the centuries, and in recent years experimental archaeology has been the main means for discovering the methods used for building the structure. ... Quarrying Stones for the Pyramids . ... and discovered that dampening the sand in front of the primitive device reduces friction on ...
Aug 04, 2021· The Great Wall easily required the greatest human effort of any ancient construction!100 million tonnes of bricks, stone, and soil were transported and assembled by millions of soldiers, peasants, prisoners, and animals using basic rope, wood, and basket systems on remote terrain ranging from parched desert to steep mountain ridges.. Read on and find out more about the labor force, terrain ...
Sep 26, 2015· 7 Primitive Cooking Methods You Still Need to Know Today. by Claude Nelson. September 26, 2015. 45. by C. Nelson. Long before we had pots and pans, men and women knelt over fires and used what nature provided to put food on their …
Architecture - Architecture - Techniques: The techniques of architecture in the sense that they will be considered here are simply the methods by which structures are formed from particular materials. These methods are influenced not only by the availability and character of materials but also by the total technological development of society, for architecture depends on an organized labour ...
Snares operate on the basic principle of tangling or strangling the target animal in a free running noose that becomes fastened around the head or feet of the quarry. The problem with using primitive methods is that cord constructed using primitive methods is not as strong and resistant to the twisting and biting subjected to it by captured ...
Mar 04, 2009· Primitive Physic: Or, an Easy and Natural Method of Curing most Diseases. John Wesley is of course well known as a founder of Methodism and writer of sermons; less well known is this medical work. His uncle was a physician; and his Puritan great grandfather had, on being thrown out of his parish after the 1660 restoration, studied theology and ...
Plug & Feather Method. Plug & Feather - Farmer's Version (circa 1774-1810) An early version of the plug & feather method. The method was an improvement over the blasting method as it often times produced pieces of stone with a flat face suitable for building with. Unlike later versions, the early plug & feather method used a maximum of 3 holes.
A founding Board Member of the Society of Primitive Technology SPT; an international organization whose aims are recording, preserving and teaching all facets of primitive technology ( skills, crafts and life ways). I am currently on the Board of the Rancocas Nature Conservancy RNC, and have served as a consultant in cultural resource studies in the Watershed since 1989.
Ice Age Lamps By Sophie A. de Beaune and Randall White, Scientific American magazine, March, 1993 issue. Benjamin Pressley lives in Stanley, North Carolina. Conquering The Darkness: Primitive Lighting Methods was published in the Bulletin of Primitive Technology, Issue #12, Fall 1996. Return to the SPT Articles, Books & Back Issues Home Page.
that quarrying with very primitive tools was carried on quite extensively in certain areas in Ohio, Tennessee, ia, and ... The method of quarrying bowlders of quartzite, fracturing by hammerstones, and reducing the quarry product to "blanks" suitable for later specialization, is well illustrated in figure 107, ...
Feb 22, 2020· Slow-going and dangerous it may have been, but ancient mining techniques were clever. The earliest mines sought cosmetic pigments for funerals. Picks and hammer stones are examples of stone age tools. Later, ancient man discovered metals which provided materials for …
1. Pitfall. A pitfall is about as simple as a trap gets for large game. A pitfall trap is simply a hole in the ground, one deep enough to completely prevent the animal from escaping or climbing out and ideally deep enough to injure or kill the animal when they fall in. All such traps will have straight, vertical or nearly vertical sides to make ...
While primitive methods were used in the beginning, the diamond wire cutting method used in Italy today became widespread. This is a pleasing situation. It is an undesirable method of operation of marble quarry because of the deterioration of quality of explosive use.
Primitive vs. Reference Data Types Primitives vs. References. primitive types are the basic types of data byte, short, int, long, float, double, boolean, char; primitive variables store primitive values; reference types are any instantiable class as well as arrays. String, Scanner, Random, Die, int[], String[], etc. reference variables store ...
Aug 09, 2021· Native Americans Tools and Weapons – Hammerstone Tools. These stone age tools are what is often used to create the flaking tools. They are made of huge stones, often attached to a stick, and is used to strike down bigger stones such as flint. They are also used for breaking bones and for pounding things, especially for food processing.
The hard part of the dry process method is grinding the clay. The hard part of the wet process is all the kneading required to mix the sand in thouroughly. Time. The wet process takes more time, using it will result in good usable clay in about a week. ... I've been making primitive pottery since I was a teenager in the 80's. My work focuses on ...
Metallurgy: Prehistoric metallurgy, mining and extraction of ores. Article: (Bulgaria - c. 3,000 BC) - Thousands of uniformly 'pressed' gold 'beads' were discovered in a Thracian horde in the Bulgarian 'Valley of the Kings'.The beads, which are only millimetres in diameter, have the appearance of minute 'washers', which show evidence of 'pressing' on both sides.
Apr 25, 2014· The techniques, equipment and even the quarry of Alabama's hunters and fishermen have changed greatly over the past 100 years. Unknown to even many of the most avid outdoorsman there are those who ...
The process of taking out stones from the natural rock is known as " quarrying " stones thus obtained are used for various engineering purposes. Before discussing the methods of quarrying, let us discuss the natural bed and plane of cleavage, which ply an important role in quarrying operation.
Ventilation methods were primitive, often limited to waving a canvas at the mouth of the shaft, and most tunnels claimed the lives of hundreds or even thousands of the slaves used as workers. In ad 41 the Romans used some 30,000 men for 10 years to push a 3.5-mile (6 …
Nov 24, 2017· The most primitive method of stone cutting involved simply hitting a soft stone with a harder one. This process dates back to, appropriately enough, the Early Stone Age. ... The Egyptians' quarrying technique consisted of digging a trench around a block of stone, then cutting beneath the stone and pushing it out.