Preface.

This tale makes no claim to the character of an exhaustive illustration of all that belongs to the art of diving. It merely deals with the most important points, and some of the most interesting incidents connected therewith. In writing it I have sought carefully to exhibit the true and to ignore the false or improbable.

I have to acknowledge myself indebted to the well-known submarine engineers Messrs Siebe and Gorman, and Messrs Heinke and Davis, of London, for much valuable information; and to Messrs Denayrouze, of Paris, for permitting me to go under water in one of their diving-dresses. Also—among many others—to Captain John Hewat, formerly¹ Commander in the service of the Rajah of Sarawak, for much interesting material respecting the pirates of the Eastern Seas.

R.M.B. Edinburgh, 1876.

1 formerly   

adv.从前，以前

参考例句：

• We now enjoy these comforts of which formerly we had only heard.我们现在享受到了过去只是听说过的那些舒适条件。
• This boat was formerly used on the rivers of China.这船从前航行在中国内河里。