1896. THE PREPARATION OF CHALK FOSSILS. 309 



well, and do not be induced to buy one of those tall silver-plated 

 erections which cost from ;^io upwards. What is kno\<rn in the trade 

 as a " S.S.White Engine," with flexible coil and short stem has 

 served me for three years without breaking down, and one wants 

 nothing better than that. If the machine does not work easily while 

 one is sitting down, discard it at once, as a proper instrument will 

 enable one to work for hours without causing fatigue. Indeed, when 

 one gets used to the movement, it becomes almost a reflex action. 

 Above all things, in choosing the engine, fit a brush or bur into the 

 hand-piece, and see if it travels true. If the hand-piece ' wobbles,' 

 the brush v/ill deviate from the straight line and describe a small 

 circle, and it will inevitably smash every specimen with which it 

 comes in contact. This engine should not be a costly affair, and 

 should be within the reach of most large collectors ; indeed, I venture 

 to say that no workshop will be complete without it. An excellent 

 engine can be bought for £2 los., and the small bristle brushes cost a 

 penny each, and the steel burs about los. a dozen. The latter can be 

 recut for a trifling cost when they are blunted. The softer bristle 

 brushes, and those made of badger-hair, should be made at home, so 

 that they can be made to suit the specimen in hand. The hand-piece 

 of the engine is the only part likely to get out of order, and occasion- 

 ally that gets clogged with dust, and has to be detached and sent to 

 the dental depot. 



It is impossible, in a short communication like this, to describe 

 the actual working of the various little tools, or to describe the tools 

 themselves, or the manufacture of the brushes. The makers will be 

 pleased to show them to anyone who is interested, and it will be a 

 pleasure to me to give a short demonstration on the process to those 

 who care to call upon me. The knives and steel brushes can be 

 obtained only of Down Brothers, St. Thomas' Street, Borough, and 

 the large bristle brushes only from Claudius Ash & Sons, Broad Street, 

 Golden Square. The burs and small bristle brushes are supplied by 

 Rutterford & Son, 11 Poland Street, Oxford Street. A dental-engine 

 can be got from Rutterford or Ash, and it is worth while to get a 

 friendly dentist to help you to chose one. 



No claim is made for any special originality in this application of 

 the dental-engine, but it is asked that the method should have a fair 

 trial, as it is reasonable to think that it is destined to revolutionise the 

 cleaning of fossils in soft rocks, and to enable the palaeontologist tO' 

 develop specimens which have hitherto been severely left alone. 

 Nobody who has once experienced the satisfaction of working with 

 this simple mechanical assistance will ever revert to the tedious and 

 clumsy method of knife and tooth-brush, and the mere time saved will 

 alone repay the worker for the small outlay. This method of cleaning 

 fossils has recently been introduced into the Natural History Museum,, 

 Cromwell Road, and into the Woodwardian Museum, Cambridge. 



A few suggestions as to mounting fossils when they are cleaned 



